242 THE POPULAR SCIENCE MONTHLY. 



the microbe-ferment of the butyric fermentation was also the agent in 

 decomposition ? He would prepare an artificial liquid, consisting of 

 phosphate of potash, magnesia, and sulphate of ammonia, added to 

 the solution of fermentable matter, and in the medium thus formed 

 would develop the microbe-ferment from a pure sowing of it. The 

 microbe would multiply and provoke fermentation. From this liquid 

 he would pass to a second and then to a third fermentable solution of 

 the same composition, and so on, and would find the butyric fermenta- 

 tion appearing in each successively. This method had been sovereign 

 in his studies since 1857. He now proposed to isolate the microbe of 

 blood infected with carbuncle, cultivate it in a pure state, and study 

 its action on animals." As he was still suffering from a partial paraly- 

 sis, he employed M. Joubert to assist him and share his honors. In 

 April, 1877, he claimed before the Academy of Sciences that he had 

 demonstrated, beyond the possibility of a reply, that the bacillus dis- 

 covered by Davaine and Rayer in 1850 was in fact the only agent in 

 producing the disease. It still remained to reconcile the facts ad- 

 duced by Messrs. Jaillard and Leplat with this assertion. The ani- 

 mals which they had inoculated died, but no bacteria could be found 

 in them. M. Paul Bert, in similar experiments, had found a disease 

 to persist after all bacteria had been destroyed. An explanation of 

 th« discrepancy was soon found. 



The bacteria of carbuncle are destroyed as soon as putrefaction 

 sets in. The virus with which these gentlemen had experimented was 

 taken from animals that had been dead twenty-four hours and had 

 begun to putrefy. They had inoculated with putrefaction, and pro- 

 duced septicaemia instead of carbuncle. All the steps in this line of 

 argument were established by irrefragable proof. M. Pasteur after- 

 ward had a similar controversy with some physicians of Turin, at the 

 end of which they shrank from the test experiment he offered to go 

 and make before them. " Remember," shortly afterward said a mem- 

 ber of the Academy of Sciences to a member of the Academy of Medi- 

 cine, who was going — in a scientific sense — to " choke " M. Pasteur, 

 " M. Pasteur is never mistaken." 



Having discovered and cultivated the microbe that produces hen- 

 cholera, Pasteur turned his attention to the inquiry whether it would 

 be possible to apply a vaccination to the prevention of these terrible 

 diseases of domestic animals. He found that he could transplant the 

 microbe of hen-cholera to an artificially prepared medium and culti- 

 vate it there, and transplant it and cultivate it again and again, to the 

 hundredth or even the thousandth time, and it would retain its full 

 strength — provided too long an interval was not allowed to elapse 

 between the successive transplantations and cultures. But if several 

 days or weeks or months passed without a renewal of the medium, 

 the culture being all the time exposed to the action of oxygen, the in- 

 fection gradually lost in intensity. A virus was produced of a strength 



