ASIATIC CHOLERA. 369 



virulent, and the virulence is increased by cultivation in the 

 peritoneal cavities of a succession of guinea-pigs. This successive 

 cultivation is carried on until a virus is obtained which proves fatal 

 in a few hours when inoculated into the peritoneum. A culture 

 from the peritoneum is obtained on an agar plate-cultivation, and 

 a pure sub-culture on agar is thoroughly shaken up with broth. 

 This constitutes the vaccinating fluid. It may be used as a living 

 vaccine, or the comma-bacilli killed by the addition of carbolic 

 acid. 



Haflfkine, having studied the pathological and physiological effects 

 on some sixty persons, mostly scientists interested in the subject, and 

 finding the treatment to be harmless, transferred his operations to 

 localities in India affected by cholera. The inhabitants of the 

 northern part of India were the first to come forward and submit 

 themselves to the inoculation. In the course of the first year 

 22,703 were inoculated in the North-West Provinces and Oudh, 

 and in the Punjab. All classes of] the population were included. 

 In the second year operations were carried out in those parts of 

 the country where cholera always prevails, and where, therefore, the 

 method could be more satisfactorily tested. 



From March 1894, to July 1895, 19,473 individuals were 

 inoculated in some of the most affected localities. 



Prom observations made at Calcutta by Dr. Simpson, from March 

 1894 to August 1895, cholera occurred in 36 houses containing 

 inoculated people. There were 521 inhabitants in the infected 

 houses, of whom 181 were inoculated from 1 to 459 days before the 

 occurrence, while 340 remained uninoculated. The uninoculated had 

 45 cases with 39 deaths from cholera ; the inoculated had 4 deaths, 

 1 occurring 451 days after the first inoculation, and 3 others from 

 1 to 4 days after the first inoculation. These four cases had not 

 been re-inoculated. If the occurrences in inoculated and non-inocu- 

 lated during the first 10 days were set aside, and those considered 

 that occurred after the 10 days expired, then, according to Dr. 

 Simpson, the proportion of cases was 19-27 and that of deaths 17'24 

 times smaller in the inoculated then in the uninoculated. 



Cholera broke out in the Gya gaol, and inoculations were made 

 after 6 cases, with 5 deaths, had occurred. During the stay of the 

 prisoners in the gaol, there were 209 uninoculated, with 7 cases and 

 5 deaths, and 211 inoculated, with 5 cases and 4 deaths. 



In July and August in the same year cholera attacked the East 

 Lancashire Regiment. Out of 773 men there were 133 inoculated 

 and 640 uninoculated, 



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