28 THE POPULAR SCIENCE MONTHLY. 



me in the belief that it is not unworthy to be brought before this 

 body. 



In preparing this discussion of the subject, I have not had access 

 to such information as would have been desirable concerning the work 

 which is being done in many institutions, nor have I been able to con- 

 sult with others who are especially engaged in its management. In- 

 deed, it was this very lack of accessible information, this very impos- 

 sibility of personal consultation, with which I met in the outset, that 

 convinced me of the importance of directing the attention of the sec- 

 tion to the subject. 



What the section could do in the direction indicated seems to be 

 tolerably clear and certain. Whether it is wise or desirable that it 

 should undertake to do anything is a matter which I willingly leave 

 for it to determine. 



MICEOSCOPIC LIFE IN THE AIE. 



By LOUIS OLIVIER. 



ANCIENT Pantheism animated all nature. Gnomes in caverns, 

 naiads in springs, sylphs in the air, represented life, pervading 

 everything. Twenty centuries having passed, science has resuscitated 

 these elementary genii under the form of organic germs ; and we are 

 forced to-day to recognize that the reality surpasses all the bold con- 

 ceptions of the fable. From pole to pole the atmosphere transports 

 myriads of microscopic animals and plants. They are counted by 

 hundreds in each cubic metre of air that we breathe in Paris. Devel- 

 oping themselves in the organic infusions into which they fall, they 

 soon determine their complete decomposition ; and they play their 

 parts in virulent diseases and in fermentations. No doubt is permis- 

 sible on this point after the admirable labors of M. Pasteur ; and every 

 day a new workman brings his stone as a contribution to the grand 

 edifice of which this illustrious physiologist has drafted the plan and 

 himself laid the impregnable foundations. 



A considerable work has just appeared on this subject. For sev- 

 eral years, M. Miquel has pursued interesting researches upon the 

 microbes of the air ; and, in addition to the regular publication of his 

 investigations in the " Annuaire " of the Observatory at Montsouris, 

 he has just completed an important memoir, which includes valuable 

 facts respecting these organisms. We propose to show here how this 

 department of science has been developed, and what means of carry- 

 ing out its objects it possesses. F. A. Pouchet devised the aeroscope 

 that bears his name, for collecting dust from the air. It consists of 

 a small cylinder connected with an aspirator ; a disk of glass coated 



