66 PASTEUR 



neighbourhood where there was much dust, 

 much slower when it was taken, for instance, 

 from the cellar of the Observatory, and in some 

 cases there was no alteration at all. 



In spite of these results, Pasteur's experi- 

 ments continued to be disputed. He resolved 

 to undertake a scientific campaign, against 

 which his adversaries should no longer be able 

 to stand out. Armed with sixty-three globes, 

 he set forth, in September, 1860, for the moun- 

 tain heights of the Alps. He halted first at Ar- 

 bois, where he took some specimens of air ; then 

 from Mount Poujet he proceeded to Chamou- 

 nix, and there he opened some of his globes 

 on the Mer de Glace. There, in that pure air, 

 far from human crowds, germs and spores 

 ought either not to exist or else to be very rare. 

 The results proved that he was right. Out of 

 twenty globes opened on the mountain heights 

 nineteen remained sterile, while in the case of 

 those into which air was admitted at lower 

 levels the proportion of sterile ones, out of the 



