678 THE UNIVERSE. 



of the country than in that of towns. Experience began by 

 invalidating this view ; then it was found that the respirable 

 gas is nevertheless a little more rare in the latter than in 

 the midst of the fields. M. Houzeau, one of our most able 

 chemists, in some experiments carried on upon a large scale, 

 found that oxygen is really a little more abundant in the 

 depths of forests, which distil it incessantly from every pore 

 of their leaves, than in our towns, where a hundred thousand 

 mouths absorb and consume it. 



This is what we know for certain relative to the chemical 

 composition of the air; let us now speak of its microscopy, 

 so easy to study, and which has yet given rise to so many 

 puerile fables. 



The ancient theogonies, full of mystery and poesy, peo- 

 pled space with an infinity of invisible and charming divin- 

 ities, who animated every part of creation. The gnomes 

 were scattered in the depths of the earth, the fire had its 

 salamanders, the naiads sported beneath the crystal waters, 

 and the sylphs, light and diaphanous as the plains of air, 

 everywhere lent life to the atmosphere in the long and 

 graceful gyrations of their dances. 



Modern philosophers, without being more precise than 

 antiquity, have been less happy. Instead of sylphs they 

 have filled, nay, surcharged, the air with an incalculable 

 quantity of germs, always ready to shed everywhere fe- 

 cundity and life. Fiction for fiction, we like that of our 

 predecessors better ; it is much more attractive, and, more- 

 over, much less crude. 



By means of these germs disseminated in every part, and 

 entering by myriads wherever the vehicle in which they 



