136 LOUIS PASTEUK. 



a passing remark, being doubtful of its importance, 

 and perhaps of its accuracy. This doubt might have 

 removed from Pasteur's mind the thought of examining 

 the significance of these little corpuscles, but, amid the 

 general confusion of opinions, Pasteur was attracted to 

 the study of these little bodies all the more readily 

 because it related to an organic element which was 

 visible only with the microscope. This instrument 

 had already rendered such services to Pasteur in his 

 delicate experiments on ferments, that he was fasci- 

 nated by the thought of resuming it again as a means 

 of research. 



I. 



On June 6, 1865, Pasteur started for Alais. The 

 emotion he felt on the actual spot where the plague 

 raged in all its force, in the presence of a problem 

 requiring solution, caused him at once to forget the 

 sacrifices he had made in quitting his laboratory at 

 the Ecole Nor male. He determined not to return to 

 Paris until he had exhausted all the subjects requiring 

 study, and had triumphed over the plague. 



In a few hours after his arrival he had already 

 proved the presence of corpuscles in certain worms, 

 and was able to show them to the President and 

 several members of the Agricultural Committee, who 

 had never seen them.' The following day he installed 



