16 



ELEMENTS OF STATIC ELECTRICITY. 



mutual repulsion of bodies at the same potential, since 

 this difference of potential between the electrified bod- 

 ies and their surroundings must produce attraction and 

 tend to separate them. 



But such outward attraction would not disprove the 

 existence of repulsion, though it might account for 

 some of its phenomena. 



THE GOLD LEAF ELECTROSCOPE As our investi- 

 gations now require a more sensitive instrument than 

 any which has yet been described, we here introduce 

 the gold leaf electroscope. 



Fig. 4 Gold Leaf Electroscopes. 



The style represented at A, Fig. 4, is convenient, and 

 easily constructed. It consists of a half-gallon tincture 

 bottle, fitted with an ebonite stopper, through the center 

 of which passes a small brass rod about five inches long, 

 which terminates about three-fourths of an inch above 

 the stopper in a brass disc about two inches in diame- 

 ter, having a round rim about three-sixteenths of an 



