UN ELECTRICAL ATTRACTIONS AND REPULSIONS. $l\ 



more will the aqueous attraction act on it, and to the 

 greater distance. 



3d Experiment 



" On a plate of metal five or six inches in diameter put 3d experi- 

 some shreds of gold leaf, and two inches above them let a 

 similar plate of metal be suspended from the conductor, 

 so as to be electrified by it. These little bits of gold leaf 

 will be immediately attracted by the upper plate, and after- 

 ward suddenly repelled to the lower, so that these attrac- 

 tions and repulsions will continue as long as the conductor 

 remains electrified. 



M To render this experiment the more pleasing," con- 

 tinues our author, " we may substitute for these bits of 

 gold leaf little painted figures, which, alternately attracted 

 and repelled by the upper plate, will appear to dance be- 

 tween the two." 



This phenomenon, as the preceding experiments, is to be No repulsion, 

 explained by the double play of affinities. These bits of 

 gold leaf, or little figures, are alternately attracted toward 

 the upper plate in consequence of their affiuity for the elec- 

 tric fluid, and toward the lower, which has a communica- 

 tion with the ground, and consequently a reciprocal affi- 

 nity for the fluid, till the conductor no longer contains 

 enough of the fluid to overcome their weight. Lastly, take 

 a fine needle with two points, that can move freely be- 

 tween the two plates, it will raise itself up, and stand erect, 

 till the electricity of the conductor is exhausted. 



4th Experiment, 



To the conductor attach a metal rod terminating in a 4th expert- 

 point. Present to this the inside of a glass, holding it in men ' 

 both hands; then place on a table some balls of pith of el- 

 der, cover them with the glass, and they will immediately 

 begin to leap up against its sides. They will continue do- 

 ing this for some time." 



In this experiment there is nothing extraordinary, and Explained on 

 . . .,.1-t i ,.l * mi similar princi- 



it is easily explained m the same manner as the others. 1 he p i ei 



substance of glass has the property of setting itself in mo- 

 tion, and then attracting the electric fluid, both by friction 



and 



