THE 



POPULAR SCIENCE 

 MONTHLY. 



JAirUAEY, 1886. 



nrOCULATIOX AGAINST HYDKOPHOBIA * 



By M. LOUIS PASTEUR. 



THE prevention of rabies, as I have described it, in my own name 

 and the names of my collaborators, in previous notes, certainly 

 constitutes a real progress in the study of that malady, a progress which 

 was, however, more scientific than practical. Its application was preca- 

 rious. Of twenty dogs that I had then treated, I could not assert that 

 I had made more than fifteen or sixteen proof against rabies. 



It was expedient, on the other hand, to finish the treatment by a 

 final exceedingly virulent inoculation, with virus of control, in order 

 to confirm and strengthen the refractory state. Finally, prudence made 

 it necessary to keep the dogs under obsei'vation for a longer time than 

 the period of incubation of the disease produced by the direct inocu- 

 lation of the last virus ; and it thus required an interval not less, per- 

 haps, than three or four months to be assured of a fully refractory 

 condition. These necessities considerably limited the application of 

 the method. The method, also, did not accommodate itself readily to 

 contingencies, which were always immediate, growing out of the acci- 

 dental and sudden character of the bites of rabid animals. It was 

 therefore necessary to obtain, if possible, a more rapid method, and 

 one more capable of giving a security which might be considered per- 

 fect over dogs. Besides, how, before reaching that stage of progress, 

 could we venture to make an experiment on man ? 



After almost innumerable experiments I obtained a preventive 

 method, practical and prompt, of which sufiiciently numerous and 

 assured successes have been gained upon dogs to give me confidence in 

 its general applicability to all animals, and to man himself. 



* A paper read in the French Academy of Sciences, October 26, 1885. 



VOL. XXTIII. — 19 



