£>g ELECTRICAL EXPERIMENTS ON GLASS. 



them ; Franklin by plus and minus; du Fay by two fluids 

 • neutralized in bodies, the particles of which repel and at- 

 tract each other ; Sec. 

 Is not the fluid ' Does not this experiment demonstrate, that the attrac- 



le y the t j ong wn j cn ac t here between the surfaces of the glass reci- 

 a; Taction be- * t ° 



tween the two procally, retain the fluid on the upper side notwithstanding 

 surfaces of the we take off tnfi cap ? wn i] e> jf ^ op p 0s j te sur f ace be not 



insulated, the cap takes it off at a distance of three or four 

 lines above it, if we touch the cap with a metallic body 

 communicating with the ground without establishing a com- 

 plete circuit; because then the ground wholly absorbs that 

 which is accumulated on the opposite surface. To verify 

 this fact, I have repeated the transvasation of water, in the 

 three following manners. 

 Water poured I charge a bottle filled with water, and pour the water 

 intcTanuninsu- mto anotner bottle standing on a plate of lead, that has a 

 latjd bottle, communication with the ground. Whether I be insulated 

 or not, when I do this, the two bottles divide the charge 

 between them. But to retain the charge in that which ha9 

 lost its water, I must place myself on an insulating stool 

 when I pour into it fresh water, unless it be from a glass 

 vessel; otherwise, as the electric fluid may escape both by 

 my body, and by the metal on which its outer surface rests, 

 and which can conduct the opposite electricity into the 

 ground, the bottle will discharge itself entirely on one side 

 by my body, and on the other toward the ground ; in the 

 same manner as a charged bottle touched by the hand, while 

 there is a communication between the ground and its oppo- 

 site side. 

 and into an in- On the contrary, if T charge a bottle highly, and pour its 

 j»ulated bottle. W ater into an insulated bottle, the water will convey away 

 nothing, and the whole charge remains in the bottle ; be- 

 cause there is no attraction of any substance to act on the 

 electric fluid, the glass, which I suppose to be saturated 

 during its fusion, having no longer any affinity to attract it. 

 It is like a full sponge, which takes up no more water, un- 

 less it can part with some of what it contains to another 

 body. It is not in the coatings then, that the fluid is re- 

 tained, but in the glass itself, and on its two sides. If, as 

 I have remarked above, I make the tranvasation into a bot- 

 tle 



