326 THE CHEMISTRY OF CREATION. 



a city were as surely doomed to destruction 

 as though the windows of heaven were opened, 

 and her living multitudes engulfed in a 'deluge 

 of waters. 



It is, however, impossible for such a condition 

 as a dead calm to exist in the atmosphere of 

 any region. It is true that to the senses there 

 may be no apparent motion in the air, and every 

 leaf of the forest may hang idly and unstirred on 

 the branches. But there are invisible movements 

 incessantly occurring in the stillest air. Not 

 only by day, but even in 



" The stillness of a moonshine heaven," 



these insensible commotions are constantly 

 taking place. Not only in the open air, but 

 in the closest shut apartment, the airy particles 

 are never at rest. This is easily proved. Let 

 the windows be closed up with shutters all but 

 a little hole through which a pencil of sunlight 

 may stream. Standing at a little distance, we 

 may perceive that the whole track of the sun- 

 beam is as it were animated. Particles of dust 

 are seen incessantly rising, falling, moving now 

 in this now in that direction, thus plainly indi- 

 cating that the air in which they float is moved 

 without ceasing. 



A part of these insensible and imperceptible 

 motions of the air are due to its elasticity and 



