ANTI-CHARBON VACCINE 



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mouse inoculate another, a little older, and it will 

 die. Passing by this method from younger to older 

 mice, we come to kill adult mice, guinea-pigs, then 

 rabbits, then sheep, etc. Thus, by transmission, 

 the virus gains strength as it goes. Doubtless this 

 increase of virulence, that we bring about by experi- 

 ment, occurs also in Nature ; and it is easy to see 

 how a microbe, usually harmless to this or that 

 species of animals, might become deadly to it. Is 

 not this the way that infective diseases have 

 appeared on the earth from age to age ? 



" See how far we have come, from the old meta- 

 physical ideas about virulence, to these microbes that 

 we can turn this way or that way — stuff so plastic 

 that a man can work 07t it, and fashion it as he 

 likes." 



Pasteur's note on the attenuation of anthrax 

 was presented to the Academie des Sciences on 

 28th February 1881 ; and the test-inoculations at 

 Pouilly-le-Fort were made in May of that year. It 

 was hardly to be expected that every country, in 

 every year, should obtain such results as France 

 now takes as a matter of course ; and at one time, 

 about eighteen years ago, there was in Hungary 

 a " conscientious objection" to the inoculation of 

 herds against the disease. In Italy, from 1st May 

 1897 t0 3 ot h April 1898, the issue of anti-charbon 

 vaccine from one institute alone, the Sero-Thera- 

 peutic Institute at Milan, was 165,000 tubes, enough 

 to inoculate 33,734. cattle and 98,792 sheep. And 

 in France, between 1882 and 1893, more than three 

 million sheep, and nearly half a million cattle, were 

 inoculated. 



