Conducting Rods. 37l 



grove of Lombardy popnlars, but knew no instance of violence done 

 to them by lightning or to the buildings which they shaded. 



Has the maple, the willow, or the birch, been known to suffer 

 from electricity ? 



Facts in relation to this question are few indeed, but what there 

 are, led to the conclusion that some trees are better conductors of 

 electricity than others. 



5. Are the amount and operations of the electric fluid con- 

 siderably affected by the growing and ripening harvest ? 



It may be regarded as an established fact, that a chemical 

 change in the form of bodies is attended with the development of 

 electricity. 



Now in the production of electricity by the sulphate of copper 

 battery, we have the decomposition of water and of the salt; and 

 the formation of an oxide of copper, and a new salt, the sulphate 

 of zinc ; and in this process, abundant electricity is set at 

 liberty. 



M. Becquerel,by a series of experiments, has shown that between 

 the plant and the soil flows an electric current, the soil being 

 positive and the plant negative ; that by the banks of a stream 

 the phenomena are complex, the alkaline waters being negative, 

 and acid waters positive. If so, then the deposit of the salts of 

 soda-potash and ammonia in vegetables may be the cause of their 

 negative electricity. And when a thunder cloud surcharged with 

 oositive electricity approaches the ripening harvests, the con- 

 ditions become such as to favor a discharge of electricity between 

 them. 



Arago says, that wheat fields, after a thunder storm of sheet 

 lightning, suffer from the breaking of the stalk and the dropping 

 of the heads of wheat. That the growing and ripening harvest 

 exercises an influence on the electrical condition of the air, may be 

 affirmed on the same grounds that warrant our conclusion that trees 

 and forests act in this way. Evidence on this subject is not abun- 

 dant, and it is to be hoped that the facts and opinions just present- 

 ed may stimulate other minds to other and more extensive re- 

 searches. 



For the Committee, 



JACOB BATCHELDER, Chairman. 



