rv .] SPONTANEOUS GENERATION. 373 



mated to amount to a tenth of that of the whole world, 

 and represented a money -value of 117,000,000 of francs, 

 or nearly five millions sterling. What may he the sum 

 which would represent the money- value of all the in- 

 dustries connected with the working up of the raw silk 

 thus produced is more than I can pretend to estimate. 

 Suffice it to say that the city of Lyons is built upon 

 French silk as much as Manchester was upon American 

 cotton before the civil war. 



Silkworms are liable to many diseases; and even 

 before 1853 a peculiar epizootic, frequently accompa- 

 nied by the appearance of dark spots upon the skin 

 (whence the name of " Pebrine " which it has receiv 

 ed), had been noted for its mortality. But in the 

 years following 1853 this malady broke out with such 

 extreme violence, that, in 1858, the silk-crop was re- 

 duced to a third of the amount which it had reached 

 in 1853 ; and, up till within the last year or two, it 

 has never attained half the yield of 1853. This means 

 not only that the great number of people engaged in 

 silk-growing are some thirty millions sterling poorer 

 than they might have been ; it means not only that 

 high prices have had to be paid for imported silkworm 

 eggs, and that, after investing his money in them, in 

 paying for mulberry-leaves and for -attendance, the cul- 

 tivator has constantly seen his silkworms perish and 

 himself plunged in ruin ; but it means that the looms 

 of Lyons have lacked employment, and that for years 

 enforced idleness and misery have been the portion of 

 a vast population which, in former days, was indus- 

 trious and well to do. 



In 1858 the gravity of the situation caused the 

 French Academy of Sciences to appoint Commissioners, 

 of whom a distinguished naturalist, M. de Quatrefages, 



was one, to inquire into the nature of this disease, and, 

 17 



