1 6 THE BEGINNINGS OF IIFE. 



living organisms ^ , and similarly, dead organic par- 

 ticles have been shown to be less and less numerous in 

 the atmosphere in proportion to the elevation obtained -. 

 In these latter experiments M. Pasteur made use of 

 yeast-water (alone or sweetened), and of urine — all 

 three of them fluids, which, after having been boiled, 

 are apt to possess only the second degree of fermenta- 

 bility. So that when we find M. Pouchet, in concert 

 with MM. Jolly and Musset, repeating these experi- 

 ments, with the sole difference that they took strong 

 infusions of hay — which experiment has almost inva- 

 riably shown to possess the first degree of fermenta- 

 bility — and that all their flasks, after a time, yielded 

 organisms from whatever mountain elevation the air 

 had been taken, this combined evidence tends most 

 strongly against the view of M. Pasteur. As the 

 germs in the fluids and in the flasks, in each set of ex- 

 periments, had been previously destroyed by ebullition, 

 and since in each set, also, air of the same character 



^ The subsidence of the atmospheric particles has been demonstrated 

 by Professor Tyndall (' Proceedings of Royal Inst.' 1870, p. 11). After 

 speaking of experiments in closed flasks, in which the air has been 

 either calcined or filtered, Gerhardt (' Chimie Organique,' t. iv. p. 545) 

 says : — ' Si dans les premieres experiences Fair calcin6 ou tamise s'est 

 montre beaucoup moins actif que I'air non soumis ^ ce traitement, c'est 

 que la chaleur rouge ou le tamisage enleve a I'air non seulement les 

 germes des infusoires et des moisissures, mais encore les debris des 

 matieres en decomposition qui y sont suspendues, c'est-a-dire les ferments 

 dont I'activite viendrait s'ajouter k celle de I'oxygene de I'air.' 



2 See M. Pouchet's ' Nouvelles Experiences sur la Generation Spon- 

 tanee/ &c., p. 69. 



