132 THE LIFE OF PASTEUR 



when, during a few days' stay at Chambery, she was seized 

 with an attack of typhoid fever, to which she succumbed 

 after two months of painful suffering. I was only able to be 

 with her for a few days, being kept here by my work, and 

 full of deceiving hopes for a happy issue from that terrible 

 disease. 



"I am now wholly wrapped up in my studies, which alone 

 take my thoughts from my deep sorrow. 



' Thanks to the facilities which you have put in my way, 

 I have been able to collect a quantity of experimental observa- 

 tions, and I think I understand on many points this disease 

 which has been ruining the South for fifteen or twenty years. 

 I shall be able on my return to propose to the Commission of 

 Sericiculture a practical means of fighting the evil and sup- 

 pressing it in the course of a few years. 



"I am arriving at this result that there is no silkworm 

 disease. There is but an exaggeration of a state of things 

 which has always existed, and it is not difficult, in my view, to 

 return to the former situation, even to improve on it. The 

 evil was sought for in the worm and even in the seed ; that was 

 something, but my observations prove that it develops chiefly 

 in the chrysalis, especially in the mature chrysalis, at the 

 moment of the moth's formation, on the eve of the function 

 of reproduction. The microscope then detects its presence 

 with certitude, even when the seed and the worm seem very 

 healthy. The practical result is this : you have a nursery full ; it 

 has been successful or it has not ; you wish to know whether to 

 smother the cocoons or whether to keep them for reproduction. 

 Nothing is simpler. You hasten the development of about 100 

 moths through an elevation of temperature, and you examine 

 these moths through the microscope, which will tell you what 

 to do. 



" The sickly character is then so easy to detect that a woman 

 or a child can do it. If the cultivator should be a peasant, 

 without the material conditions required for this study, he can 

 do this : instead of throwing away the moths after they have 

 laid their eggs, he can bottle a good many of them in brandy 

 and send them to a testing office or to some experienced person 

 who will determine the value of the seed for the following 

 year." 



The Japanese Government sent some cases of seed supposec 

 to be healthy to Napoleon III, who distributed them in the 



