148 PASTEUR AND HYDROPHOBIA III 



The period of incubation of hydrophobia being 

 usually four or five weeks, it seemed to M. Pasteur 

 not impossible that he might succeed by the method 

 which he had carried out in dogs in rapidly producing 

 in human subjects a state of refractoriness to the 

 poison of rabies by using a virus of rapid activity, 

 and so, as it were, overtake the more slowly acting 

 virus injected into the system by the bite of a mad 

 dog. 



Whatever may have been his theoretical concep- 

 tions, M. Pasteur determined to have recourse to the 

 one great and fertile source of new knowledge ex- 

 periment. 



It is known that inoculation with vaccine virus 

 during the latent period of small-pox has an effect in 

 modifying the disease in a favourable direction, and 

 so in any case it was to be expected that the inocula- 

 tion of individuals during the latent period of hydro- 

 phobia might produce favourable results. M. Pasteur 

 had every reason to believe that, at any rate, the 

 inoculation which he proposed would not have injuri- 

 ous results. He could proceed to the trial with a 

 clear conscience, feeling sure that he was in any case 

 giving the bitten person a better chance of recovery 

 than he would have if left untreated. 



The first human being treated by Pasteur was the 

 child Joseph Meister, who was sent from Alsace by 

 Dr. Weber and arrived in M. Pasteur's laboratory on 

 the 6th of July 1885. This child had been bitten a 

 few days previously, in fourteen different places, by a 

 mad dog, on the hands, legs, and thighs. MM. Vul- 



