VETERINARY PROBLEMS. 19 



spicuoiis in the studies to which I have alluded, succeeded 

 in cultivating the virus of a contagious disease in such a 

 manner that other germs were excluded. It was the virus 

 of fowl cholera, and he soon learned that the preservation of 

 this virus, under certain conditions in the laboratory, modified 

 it, diminished its virulence, and enabled him to use it safely 

 for conferring an immunity, as vaccine is used for protecting 

 from small-pox. 



Anthrax virus was then subjected to similar conditions, and 

 it, too, was changed into a vaccine. We have all heard of 

 the wonderful success of the vaccinations with attenuated 

 anthrax virus in France, — how hundreds of thousands of 

 -animals have been made insusceptible to this destructive 

 «courge at a very slight expense, and almost without loss. 

 We have also heard criticisms of Pasteur, criticisms of his 

 methods, doubts of his alleged discoveries, insinuations in 

 resrard to his standins^ as a scientist, — all orio-inatinsr from 

 men who envy him the position which he has attained 

 by years of patient toil, and by a devotion to science of 

 which few are capable. But let us forget these unpleasant 

 things ; they are unworthy of the scientific men of this gen- 

 eration ; let us rise superior to national jealousy, superior 

 to personal envy, and during the lifetime of such worthy 

 men, make it known that their gifts to humanity are duly 

 appreciated. 



Though the discovery of the attenuation of virus can no 

 longer be contested, Pasteur's theory in regard to this has 

 become untenable. I was, perhaps, the first to show that it 

 was not the oxygen of the air which produced the change in 

 germs, but that it was a loss of activity due to their old age, 

 when preserved where multiplication was impossible. Chau- 

 veau has since added evidence which makes it very certain 

 that this view is correct ; and he and others have shown that 

 the same loss of activity results from other unfavorable con- 

 ditions of life, such as high temperature and contact with 

 certain chemical substances known as disinfectants. There 

 are, then, various ways in which an attenuated virus or vac- 

 cine may be produced, and some of these are much quicker 

 and more uniform in their results than that of Pasteur, but 

 all have certain objections. Pasteur's method requires much 



