744 POPULAR SCIENCE MONTHLY. 



and, above all, more intensive that is to say, the virulent cord is 

 injected several times." 



The statistics arranged with reference to the location of the 

 bite are given by Perdrix as follows : 



Bitten upon the head, 684 ; died, 12 = 1'75 per cent ; 

 Bitten upon the hands, 4,396 ; died, 9 = 0-2 per cent ; 

 Bitten upon the limbs, 2,839 ; died, 6 = 0'17 per cent. 



In the infectious diseases of man, which have been proved to 

 be due to pathogenic bacteria, the most satisfactory evidence of 

 the value of protective inoculations has been obtained in cholera 

 and in diphtheria. In the first-mentioned disease protective in- 

 oculations were practiced on a large scale in Spain, during the 

 epidemic of 1884 and 1885, by the method of Ferran. This con- 

 sisted in the introduction of a small amount of a pure culture of 

 the cholera spirillum into the subcutaneous connective tissue, by 

 means of a hypodermic syringe. Shakespeare, who was sent by 

 our Government to investigate the merits qf this method of 

 prophylaxis, was disposed to think well of it. He says : 



" There is still another result of the preventive inoculations of 

 Ferran apparently shown by these statistics. I refer to the ap- 

 parent marked shortening of the course of the epidemic after a 

 large percentage of the inhabitants have become inoculated. It 

 would seem, therefore, from analysis of the official statistics, that 

 the practice of the anticholeraic inoculation after the method of 

 Ferran, besides giving the subject inoculated a considerable im- 

 munity from attack and death by cholera, furnishes a means of 

 bringing an epidemic rapidly to an end." 



More recently Haffkine has advanced evidence in favor of the 

 protective value of subcutaneous inoculations with cholera cul- 

 tures. His experiments in India have been made in Calcutta, 

 Gaya, Cawnpore, and Lucknow. Those exposed, during the epi- 

 demic prevalence of cholera, under the same conditions as to 

 locality, water supply, etc., are divided into two groups, the inoc- 

 ulated and the non-inoculated. In the first group, which includes 

 500 inoculated individuals, 21 cases occurred, of which 19 were 

 fatal, a mortality of 3 '8 per cent. In the second group were 1,735 

 individuals ; the number of cases in this group was 174; number 

 of deaths, 113; percentage of mortality, 6'51. 



Whether this method will be found to have any great practi- 

 cal value can only be determined by more extended experiments. 

 But in view of the fact that other measures of prophylaxis, well 

 known to sanitarians, are sufficient for the prevention of cholera 

 epidemics, and that nurses and others who necessarily come in 

 contact with cholera patients are not likely to contract the disease 

 if they use proper precautions with reference to their food and 



