102 



ANTHRAX 



" Along with the bacilli, there are blood-cells and 

 blood-plasma, and these contain the true amorphous 

 virus of anthrax." Then came Pasteur's work, and 

 reached its end in the experiments at Chartres, and 

 the famous test-inoculations ( 1 88 1 ) at Pouilly-le- 

 Fort. 



In the Agenda du Chimiste (1896) M. Roux 

 gives the following account of this work, which he 

 watched from first to last : — 



" Vaccination against charbon has now been put 

 to the test of practice for fourteen years. Wherever 

 it is adopted, there the losses from charbon have 

 become insignificant. It was followed by vaccina- 

 tion against swine-measles, rouget des pores, the 

 special study of our poor friend Thuillier. But 

 the immediate result of Pasteur's vaccinations is 

 their least merit : they have given men absolute 

 faith in a science that could show such good works, 

 they have started a movement that is irresistible ; 

 above all, they have set going the whole study of 

 immunity, which is bringing us at last to a right 

 way of treating infective diseases. 



" Virulence is a quality that microbes can lose, 

 or can acquire. Suppose we came across the 

 anthrax-bacillus so far attenuated, in the way of 

 Nature, that it had lost all power to kill — of course 

 we should fail to recognise it ; we should take it 

 for an ordinary bacillus of putrefaction : you must 

 watch it through each phase of its attenuation, to 

 know that the harmless organism is the descendant 

 of the fatal virus. But you can give back to it the 

 virulence that it has lost, if you put it, to begin 

 with, under the skin of a very delicate subject, a 

 mouse only one day old. With the blood of this 



