CHOLERA. 279 



man) for a powerful vaccine, which, were it not preceded 

 by the weaker form, would bring about extensive tissue- 

 necrosis and perhaps death. Protection certainly seems 

 to follow the operation of these vaccines. 



Haffkine's studies embrace more than 40,000 inocula- 

 tions performed in India. From his latest paper (Dec. , 

 1895) the following extract will show the results : 



u i. In all those instances where cholera has made a 

 large number of victims, that is to say, where it has 

 spread sufficiently to make it probable that the whole 

 population, inoculated and uninoculated, were equally 

 exposed to the infection, in all these places the results 

 appeared favorable to inoculation. 



U 2. The treatment applied after an epidemic actually 

 breaks out tends to reduce the mortality even during the 

 time which is claimed for producing the full effect of the 

 operation. In the Goya Garl, where weak doses of a 

 relatively weak vaccine had been applied, this reduction 

 was to half the number of deaths ; in the coolies of the 

 Assam-Burmah survey-party, where, as far as I can gather 

 from my preliminary information, strong doses have been 

 applied, the number of deaths was reduced to one-seventh. 

 This fact would justify the application of the method in- 

 dependently of the question as to the exact length of time 

 during which the effect of this vaccination lasts. 



"3. In L,ucknow, where the experiment was made on 

 small doses of weak vaccines, a difference in cases and 

 deaths was still noticeable in favor of the inoculated 

 fourteen to fifteen months after vaccination in an epidemic 

 of exceptional virulence. This makes it probable that a 

 protective effect could be obtained even for long periods 

 of time if larger doses of a stronger vaccine were used. 



" 4. The best results seem to be obtained from applica- 

 tion of middle doses of both anticholera vaccines, the 

 second one being kept at the highest possible degree of 

 virulence obtainable. 



4 * 5. The most prolonged observations on the effect of 

 middle doses were made in Calcutta, where the mortality 



