98 THE LIFE OF PASTEUR 



where Pasteur slept ; nearly all of them presented altera- 

 tions. 



In the meanwhile the guide was sent to Chamonix where a 

 tinker undertook to modify the lamp in view of the coming 

 experiment. 



The next morning, twenty flasks, which have remained cele- 

 brated in the world of scientific investigators, were brought to 

 the Mer de Glace. Pasteur gathered the air with infinite pre- 

 cautions ; he used to enjoy relating these details to those people 

 who call everything easy. After tracing with a steel point a 

 line on the glass, careful lest dusts should become a cause of 

 error, he began by heating the neck and fine point of the bulb 

 in the flame of the little spirit-lamp. Then raising the vessel 

 above his head, he broke the point with steel nippers, the long 

 ends of which had also been heated in order to burn the dusts 

 which might be on their surface and which would have been 

 driven into the vessel by the quick inrush of the air. Of those 

 twenty flasks, closed again immediately, only one was altered. 

 " If all the results are compared that I have obtained until 

 now," he wrote, on March 5, 1880, when relating this journey 

 to the Academie, "it seems to me that it can be affirmed that 

 the dusts suspended in atmospheric air are the exclusive origin, 

 the necessary condition of life in infusions." 



And in an unnoticed little sentence, pointing already then to 

 the goal he had in view, " What would be most desirable would 

 be to push those studies far enough to prepare the road for a 

 serious research into the origin of various diseases." The 

 action of those little beings, agents not only of fermentation but 

 also of disorganization and putrefaction, already dawned upon 

 him. 



While Pasteur was going from the Observatoire cellars to the 

 Mer de Glace, Pouchet was gathering air on the plains of 

 Sicily, making experiments on Etna, and on the sea. He saw 

 everywhere, he wrote, ' air equally favourable to organic 

 genesis, whether surcharged with detritus in the midst of our 

 populous cities, or taken on the summit of a mountain, or on 

 the sea, where it offers extreme purity. With a cubic deci- 

 metre of air, taken where you like, I affirm that you can ever 

 produce legions of microzoa." 



And the heterogenists proclaimed in unison that "every- 

 where, strictly everywhere, air is constantly favourable to life." 

 Those who followed the debate nearly all leaned towards 



