OF DEW. 197 



surfaces ; and as the air has access to all surfaces, 

 except the interior surfaces of air-tight vessels, 

 the dew may form on the side of a substance or 

 under it, just the same as on the top ; for while 

 the water in the air is invisible vapour, and floats 

 in the air, it must go with the air wherever that 

 goes ; and though it is under an inverted basin on 

 the grass, there is no reason, if the surface cools 

 as rapidly, why there should not be dew there as 

 well as any where else. If, indeed, the basin is 

 inverted before sunset, there should be, and really 

 there is, more dew there than upon the same sur- 

 face of the exposed grass. Take a large flower- 

 pot, and turn it down a little before sunset, and 

 leave it a little after sunrise, on the same spot, for 

 a week, and you will find a circle of stronger and 

 greener grass than that around. Even if you 

 keep the pot constantly on the place till the grass 

 becomes yellow, you will find that it is light that 

 has been wanting, and not moisture. Every 

 gardener knows that fact, and acts practically 

 upon it, when he turns down a flower-pot over 

 his pipings of pinks or carnations to make them 

 strike, by nourishing them with the gentle dew 

 which their own cool leaves melt out of the 

 warmer air. A shady tree will refresh a man 

 with dew when he escapes from the burning sun, 

 even though he be so hot that that dew is evapo- 

 rated again before it touches him. 



The dew forms into beautiful drops on those 

 surfaces, between which and it there is a sort of 

 repulsion. Vegetable leaves when in action have 

 that quality, and hence the beauty of the morning 

 dew on the grass. If those who are fond of look- 

 ing at gems would get up in the morning, when 

 s 3 



