300 THE LIFE OF PASTEUR 



menon, " if you take each of these attenuated cultures as a 

 starting-point for successive and uninterrupted cultures, all 

 this series of cultures will reproduce the attenuated virulence 

 of that which served as the starting-point ; in the same way 

 non-virulence will reproduce non-virulence." 



And, while hens who had never had chicken-cholera perished 

 when exposed to the deadly virus, those who had undergone 

 attenuated inoculations, and who afterwards received more 

 than their share of the deadly virus, were affected with the 

 disease in a benign form, a passing indisposition, sometimes 

 even they remained perfectly well ; they had acquired 

 immunity. Was not this fact worthy of being placed by the 

 side of that great fact of vaccine, over which Pasteur had so 

 often pondered and meditated? 



' He now felt that he might entertain the hope of obtaining , 

 through artificial culture, some vaccinating-virus against the 

 virulent diseases which cause great losses to agriculture in the 

 breeding of domestic animals, and, beyond that, the greater 

 hope of preserving humanity from those contagious diseases 

 which continually decimate it. This invincible hope led him 

 to wish that he might live long enough to accomplish some new 

 discoveries and to see his followers step into the road he had 

 marked out. 



Strong in his experimental method which enabled him to 

 produce proofs and thus to demonstrate the truth ; able to 

 establish the connection between a virulent and a microbian 

 disease; finally, ready to reproduce by culture, in several 

 degrees of attenuation, a veritable vaccine, could he not now 

 force those of his opponents who were acting in good faith to 

 acknowledge the evidence of facts? Could he not carry all 

 attentive minds with him into the great movement which was 

 about to replace old ideas by new and precise notions, more 

 and more accessible? 



Pasteur enjoyed days of incomparable happiness during that 

 period of enthusiasm, joys of the mind in its full power, joys of 

 the heart in all its expansion ; for good was being done. He 

 felt that nothing could arrest the course of his doctrine, of 

 which he said ' ' The breath of Truth is carrying it towards 

 the fruitful fields of the future." He had that intuition which 

 makes a great poet of a great scientist. The innumerable ideas 

 surging through his mind were like so many bees all trying to 

 issue from the hive at the same time. So many plans and pre- 

 conceived ideas only stimulated him to further researches; but, 



