134 LOUIS PASTEUR. 



Pasteur at first declined this offer. It was at the 

 moment when the results of his investigations on 

 organised ferments opened to him a wide career ; it 

 was at the time when, as an application of his latest 

 studies, he had just recognised the true theory of the 

 fabrication of vinegar, and had discovered the cause of 

 the diseases of wines; it was, in short, at the moment 

 when, after having thrown light upon the question of 

 spontaneous generation, the infinitely little appeared 

 infinitely great. He saw living ferments present every- 

 where, whether as agents of decomposition employed to 

 render back to the atmosphere all that had lived, or 

 as direct authors of contagious maladies. And now 

 it was proposed to him to quit this path, where his 

 footing was sure, which offered him an unlimited 

 horizon in all directions, to enter on an unknown 

 road, perhaps without an outlet. Might he not expose 

 himself to the loss of months, perhaps of years, in 

 barren efforts ? 



M. Dumas insisted. ' I attach,' said he to his old 

 pupil, now become his colleague and his friend, * an 

 extreme value to your fixing your attention upon 

 the question which interests my poor country. Its 

 misery is beyond anything that you can imagine.' 



' But consider,' said Pasteur, * that I have never 

 handled a silkworm.' 



* So much the better,' replied M. Duinas. ' If you 

 know nothing about the subject, you will have no 



