chap, ix PROTECTIVE INOCULATION 245 



the value of a prophylactic injection of the Haffkine 

 fluid. 



Simpson (in the Practitioner for December 1905) 

 says : " The Indian Plague Commission, while accepting 

 the facts which proved the general protective effect of the 

 prophylactic, were indisposed to follow Haffkine in his 

 conclusion as to protection in the incubation stage. They 

 recorded their opinion that, ' in view of the short incuba- 

 tion period of plague, and in view of the fact that our 

 experience in the case of other diseases, both in animals 

 and man, indicates that protection is not at all rapidly 

 established, it seems to us unlikely that the anti-plague 

 inoculation can exert any favourable influence on persons 

 who are already incubating plague.' 1 Further facts laid 

 before them appear, however, to have somewhat modified 

 their view, for in the conclusion to their Report they 

 state that ' inoculation does not appear to confer any 

 great degree of protection within the first days after 

 the inoculation has been performed.' 2 



" Calmette and the Oporto International Commission 

 went still further, for they demonstrated, by actual 

 experiment on mice, that Haffkine's prophylactic rendered 

 these animals immune only after an elapse of eight to 

 ten days, and that the prophylactic, given simultaneously 

 with a small and feeble dose of the plague virus, increased 

 the virulence of the disease, rendering death certain even 

 in cases in which there might otherwise be a percentage 

 of recoveries. 



" Calmette and Salimbeni, in their Report, conclude 

 that ' it is certain that after injection of the prophylactic, 



1 Report of the Indian Plague Commission, vol. v. p. 252. 

 * Ibid. p. 262. 



