ANTHRAX. 141 



of preparing a vaccine virus, which is, however, 

 analogous to that of Pasteur. He subjects the lymph 

 of the blood of a diseased animal to a temperature 

 of 50, and thus transforms it into vaccine. Toussaint 

 considers the high temperature to be the principal 

 agent of attenuation, and ascribes little or no im- 

 portance to the action of the oxygen in the air. 



Chamberland and Roux have recently made re- 

 searches with the object of obtaining a similar 

 vaccine by attenuating the primitive virus by means 

 of antiseptic substances. They have ascertained that 

 a solution of carbolic acid of one part in six hundred 

 destroys the microbes of anthrax, while they can live 

 and nourish in a solution of one part in nine hundred, 

 but without producing spores, and their virulence is 

 attenuated. When a nourishing broth is added to 

 a solution of one in six hundred, the microbe can live 

 and grow in it for months. Since the chief condition 

 of attenuation consists in the absence of spores, this 

 condition seems to be realized by the culture in a 

 solution of carbolic acid, one in nine hundred, and it 

 is probable that a fresh form of attenuated virus 

 may thus be obtained. Diluted sulphuric acid gives 

 analogous results. 



However this may be, the vaccine prepared by 

 Pasteur's process is the only one which has been 

 largely used, and which has afforded certain results to 

 cattle-breeders. 



Public experiments, performed before com mis- 



