1 86 BACTERIA IN DAILY LIFE 



titles of stronger and stronger venom are in turn injected, 

 first considerably diluted, and then more concentrated ; 

 and when the animals have already acquired a sufficiently 

 perfect immunity, the venoms derived from as large a 

 number of different species of snakes as possible are 

 injected. The duration of the treatment is of consider- 

 able length at least fifteen months before the serum 

 is sufficiently active to be used for the purposes of treat- 

 ment." 



An immense number of animals have been 

 vaccinated by this method at the Pasteur Insti- 

 tute at Lille, where Dr. Calmette is now director ; 

 and in one of his memoirs we are told that they 

 have horses there which have yielded during a 

 period of eighteen months serum extremely active 

 against venom. These horses receive in a single 

 inoculation, without suffering the least inconveni- 

 ence, doses of venom sufficient to kill fifty horses 

 fresh to the treatment. 



Large quantities of this serum have been for- 

 warded from the Lille Institute to various parts 

 of the world where venomous serpents are most 

 frequently met with, and already important evi- 

 dence has been collected as to its efficacy in cases 

 of human beings bitten by dangerous reptiles. So 

 impressed with its importance are Indian medical 

 authorities, that its preparation has been included 

 in the work which the new great bacteriological 

 institute at Agra is carrying on. 



