306 THE LIFE OF PASTEUR 



little ones of whom I was one. I am now the only survivor of 

 my paternal and maternal families." 



In the first days of August, Toussaint, the young professor 

 of the Toulouse Veterinary School, declared that he had suc- 

 ceeded in vaccinating sheep against splenic fever. One process 

 of vaccination (which consisted in collecting the blood of an 

 animal affected with charbon just before or immediately after 

 death, defibrinating it and then passing it through a piece of 

 linen and filtering it through ten or twelve sheets of paper) had 

 been unsuccessful ; the bacteridia came through it all and 

 killed instead of preserving the animal. Toussaint then had 

 recourse to heat to kill the bacteridia: "I raised," he said, 

 "the defibrinated blood to a heat of 55 C. for ten minutes; 

 the result was complete. Five sheep inoculated with three 

 cubic cent, of that blood, and afterwards, with very active 

 charbon blood, have not felt it in the least." However, several 

 successive inoculations had to be made. 



"All ideas of holidays must be postponed; we must set to 

 work in Jura as well as in Paris," wrote Pasteur to his assist- 

 ants. Bouley, who thought that the goal was reached, did not 

 hide from himself the difficulties of interpretation of the alleged 

 fact. He obtained from the Minister of Agriculture permission 

 to try at Alfort this so-called vaccinal liquid on twenty sheep. 



"Yesterday," wrote Pasteur to his son-in-law on August 

 13, "I went to give M. Chamberland instructions so that I 

 may verify as soon as possible the Toussaint fact, which I will 

 only believe when I have seen it, seen it with my own eyes. 

 I am having twenty sheep bought, and I hope to be satisfied as 

 to the exactitude of this really extraordinary observation in 

 about three weeks' time. Nature may have mystified M. 

 Toussaint, though his assertions seem to attest the existence of 

 a very interesting fact." 



Toussaint 's assertion had been hasty, and Pasteur was not 

 long in clearing up that point. The temperature of 55 C. 

 prolonged for ten minutes was not sufficient to kill the bac- 

 teridia in the blood ; they were but weakened and retarded in 

 their development ; even after fifteen minutes' exposure to 

 the heat, there was but a numbness of the bacteridium. Whilst 

 these experiments were being pursued in the Jura and in the 

 laboratory of the Ecole Normale, the Alfort sheep were giving 

 Bouley great anxiety. One died of charbon one day after 

 inoculation, three two days later. The others were so ill that 



