1880—1882 85 



M. Nocard wanted to sacrifice one in order to proceed to 

 immediate necropsy ; Bouley apprehended a complete disaster. 

 But the sixteen remaining sheep recovered gradually and 

 became ready for the counter test of charbon inoculation. 



Whilst Pasteur was noting the decisive points, he heard 

 from Bouley and from Roux at the same time, that Toussaint 

 now obtained his vaccinal liquid, no longer by the action of 

 heat, but by the measured action of carbolic acid on splenic 

 fever blood. The interpretation by weakening remained the 

 same. 



"What ought we to conclude from that result?" wrote 

 Bouley to Pasteur ' It is evident that Toussaint does not 

 vaccinate as he thought, with a liquid destitute of bacteridia, 

 since he gives charbon with that liquid ; but that he uses a 

 liquid in which the power of the bacteridium is reduced by 

 the diminished number and the attenuated activity. His vac- 

 cine must then only be charbon liquid of which the intensity 

 of action may be weakened to the point of not being mortal to 

 a certain number of susceptible animals receiving it. But it 

 may be a most treacherous vaccine, in that it might be capable 

 of recuperating its power with time. The Alfort experiment 

 makes it probable that the vaccine tested at Toulouse and found 

 to be harmless, had acquired in the lapse of twelve days before 

 it was tried at Alfort, a greater intensity, because the bac- 

 teridium, numbed for a time by carbolic acid, had had time to 

 awaken and to swarm, in spite of the acid." 



Whilst Toussaint had gone to Rheims (where sat the French 

 Association for the Advancement of Science) to state that it 

 was not, as he had announced, the liquid which placed the 

 animal into conditions of relative immunity and to epitomize 

 Bouley 's interpretation, to wit, that it was a bearable charbon 

 which he had inoculated, Pasteur wrote rather a severe note on 

 the subject. His insisting on scrupulous accuracy in experi- 

 ment sometimes made him a little hard ; though the process was 

 unreliable and the explanation inexact, Toussaint at least had 

 the merit of having noted a condition of transitory attenuation 

 in the bacteridium. Bouley begged Pasteur to postpone his 

 communication out of consideration for Toussaint 



One of the sheep folded over splenic-fever pits had died on 

 August 25, its body, full of bacteridia, proving once more the 

 error of those who believed" in the spontaneity of transmissible 

 diseases. Pasteur informed J. B. Dumas of this, and at the 



x 2 



