BOOK VIII. 



THE AlPt AND ITS COEPUSCULES. 



The aerial ocean .which envelops the earth is from 

 fifteen to sixteen leagues high. It is the medium for 

 diflPusing animation and life, and its disappearance would 

 be immediately followed by a general destruction of ani- 

 mals and plants, and the silence of death. 



The vital principle of the air, or oxygen, enters into its 

 composition to the extent of iVd-. It has been generally 

 thought that this element is found in the same proportion 

 over the whole sxirface of the globe. According to M. 

 IMartins, the air of the Faulhorn, one of the highest moun- 

 tains in Switzerland, yields the same percentage of oxygen 

 as that of Paris. 



Paradoxes have always had a certain success. Some 

 chemists maintained that the air in hospitals, drains, and 

 even the foulest places, maintains all its purity.^ Notwith- 

 standing these different assei'tions, as a great deal of oxygen 

 is consumed in populous cities, whilst plants are continually 

 pouring it out into the atmosphere, it seemed a jyriori as 



1 In a prize memoir of a ]oroviiicial academy, M. Julia Fontenelle Las 

 maintained tliat tlie air of hospitals, and even of sewers, is as pure as that of our 

 fields. 



