68 
Pasteur and his Work, 
all the cultivations from every part of Europe were either dis- 
eased or suspected of being so ; and throughout the extreme 
East, Japan only was exempt. The plague had followed the 
trade in silkworm eggs, just as cattle diseases have followed the 
trade in cattle. 
In 1865, the weight of cocoons had fallen so low, that the 
French revenue sustained a loss of 100,000,000 francs, ami the 
silk-cultivating Departments were in despair. Agricultural and 
scientific societies, municipal bodies and governments, were all 
seriously engaged in attempting to discover the cause and a 
remedy. And there was no lack of hypotheses, suggestions, 
and cures ; while scores of pamphlets upon the malady were 
published every year, and experiments were undertaken to 
elucidate the mysterious scourge, and limit its ravages. 
The disease was known as " pebrine," owing to the peppered 
appearance of the skin of diseased worms. 
In 1865, in response to a petition signed by 3600 mayors, 
municipal councillors, and capitalists of the severely-visited 
Departments, the French Government appointed a Commission to 
investigate the malady, and Dumas was selected as its Chairman 
or reporter, because of his great scientific reputation and his 
personal interest in one of the afflicted Departments. While 
preparing his report, it occurred to him that Pasteur was the 
man best fitted to carry out investigations as to the measures 
required to combat the plague. But Pasteur at first declined 
to undertake such a heavy task, inasmuch as his success in the 
enquiry into organised ferments, in their relation to the manu- 
facture of vinegar and diseases of wines, had opened prospects 
of a prosperous career — in fact, it was at the moment when, dis- 
posing of the vexed question of spontaneous generation, the " in- 
finitely little " had become to him, and to science, the " infinitely 
great." He saw living ferments everywhere, either as the active 
agents in decomposition or in producing contagious disorders. 
To forsake a course which he had so fruitfully pursued and made 
his own, with all its prospective advantages, and to enter upon 
another which was novel to him, and the determination of which 
might be the reverse of satisfactory, appeared to be too much 
of a sacrifice. Dumas appealed to his friendship and his 
patriotism. " But consider," said Pasteur, " that I have never 
handled a silkworm." " So much the better," replied Dumas. 
" If you know nothing about the subject, you will have no 
other ideas than those which you will derive from your own 
observations." 
Being at length persuaded to undertake the duty, he had to 
decide upon the method to be adopted in his endeavour to dis- 
charge it. For seventeen years hypotheses and observations with 
