TEEES AS ELECTEIC AGENTS. 



To a poetical mind there is no exercise more agreeable 

 than that of tracing in the economy of Nature certain 

 trains of causes and effects that seem to represent her as 

 a kind benefactor, aiming to promote the happiness of 

 all creatures. While we treat of the beauty of trees and 

 of their capacity to afford shelter, shade, and salubrity, it 

 is pleasant, while continuing our observations, to find no 

 end to the advantages that flow from them. We have 

 studied them as the beautifiers of landscape, as the sources 

 of vitality and salubrity in the atmosphere, as our shade 

 in summer and our shelter in winter ; as the cause of 

 equability, both of temperature and of moisture. We 

 may also discover in them and their branches an infinite 

 number of lightning-rods, presenting millions of points 

 both for the discharge and the absorption of electricity. 

 Trees differ from other plants in this respect only by pre- 

 senting their points at a greater elevation, where they can 

 act more immediately upon the clouds. 



Trees, especially in dense assemblages, may therefore, 

 in frequent instances, be the immediate occasion of show- 

 ers, by conducting to the earth the electric fluid of the 

 clouds, and inducing that non-electric \state which pre- 

 cedes the discharge of rain. This seems to be effected 

 by electric disorganization. An organized cloud is an 

 aggregation of vaporous particles, which are suspended 

 in the atmosphere and held in a state of union with- 

 out contact. Being in a similarly electrified condition, 

 they are kept separate by that law of electricity which 



