JULY. 239 



less : in that case I presume we do not see the flash itself, 

 but the illumination of the atmosphere consequent on it ; 

 the reflection in the sky, as it is called ; the clouds contain- 

 ing the electricity being beneath the horizon, and therefore 

 invisible. 



C. What an exhilarating freshness and purity there is 

 in the air, this morning ; similar to that which is perceived 

 on mountain summits, or any great elevation. 



F. For this we are indebted to the trees and plants 

 around us : all vegetables give out oxygen by day, the life- 

 giving part of the air we breathe ; but after the excitement 

 of a thunder-storm, it is evolved in much greater profusion, 

 which has a refreshing and enlivening effect on animal 

 spirits. 



C. How delightfully fresh and green the trees and 

 herbage look ! the leaves are yet sparkling with the rain- 

 drops: see the long, seedy grass bowing its heavy head 

 under the weight of moisture ; what a silvery appearance it 

 has ! it is almost ready for the scythe. 



F. Let us climb this hill, whence we may look down 

 on the lowlands and bottoms. I should have rather said, 

 we can look towards them ; for I perceive they are hidden 

 by a dense film of mist or fog, that lies upon them. 



C. What is the cause of its covering the land so par- 

 tially ? 



F. When the rain fell last night, the earth had been 

 heated to a considerable extent: much of the water was 

 evaporated, and rose in invisible vapour, but now that the 

 morning air is cool, the vapour is condensed, and falls in the 

 form of a thick fog upon the low lands. Often during a 

 season of dry weather, if we stand on a hill at early day 

 light, we may trace the river through all its circuitous wind- 

 ings through the forest, (though no part of it is visible,) by 

 the belt of white fog which hangs over it, but which is 



