230 LOUIS PASTEUR. 



from it beyond its actual application, which is the one 

 result achieved. 'Vaccination is vaccination,' an 

 opponent of Pasteur's, who was driven hard, was 

 obliged to say. The opponent found no other answer, 

 and he could not have found any other. The cow-pox 

 is a malady belonging exclusively to a race of animals. 

 Man can only observe it ; he cannot produce it. Sup- 

 press cow-pox and there will be no more vaccination. 

 In the French discovery, on the contrary, it is the 

 deadly virus itself which serves as a starting point for 

 the vaccine. It is the hand of man which makes the 

 vaccine, and this vaccine may be artificially prepared 

 in the laboratory, in sufficient quantity to supply all 

 needs. What a future is presented to the mind in the 

 thought that the virus and its vaccines are a living 

 species, and that in this species there are all sorts of 

 varieties susceptible of being fixed by artificial cultiva- 

 tion ! The genius of Jenner made a discovery, but 

 Pasteur discovered a method of genius. 



' This is but a beginning,' said M. Bouley on the 

 day when Pasteur announced these facts to the 

 Academy of Sciences. ' A new doctrine opens itself in 

 medicine, and this doctrine appears to me powerful 

 and luminous. A great future is preparing ; I wait 

 for it with the confidence of a believer and with the 

 zeal of an enthusiast.' 



