302 Ley den Phial difcovsred. [Book IV. 



trificd, and fufpended on filk line.-, that if die perfon 

 and the metal changed places the off! ct woflld be ;he 

 fame. He accordingly fufpenueci a piece of metal 

 by filk threads near his excited tu^e^ ; he 



drew fparks from it at pleafure. This was the origin 

 of metallic condu&ors. Mr. Grey fufpedted that Jie 

 electric fire might be of the iume nature with thun- 

 der and lightning. 



To the philofophers of Germany rve are indebted 

 for moft of the improvers !".> in thr c!t Jtrical appa- 

 ratus. They revived the ule of the gio'>e, vvLkh had 

 been invented by Mr. Hawkfbee, which was after- 

 wards fuperfeded by a cylinder, and to which they im- 

 parted a circular motion by means of wheels, and ufed 

 a woollen rubber inftead of the hand. By the great 

 force alfo of their machines, they were able to fire 

 fome of the moft inflammable fubftances, fuch as 

 highly rectified fpirits, by the electric fpark. 



But the moft lurprizing difcovery was that which 

 immediately followed thefe attempts, in the years 

 1745-6 ; I mean the method of accumulating the 

 electric power by the Leyden phial. M. Von Kleift, 

 dean of the cathedral of Carnnin, was the firfl who 

 found that a nail or hrafs wire, confined in an apothe- 

 cary's phial, and expofed to the electrifying glafs or 

 prime conductor, had a power of collecting the elec- 

 tric virtue fo as to produce the moft remarkable 

 effeds - s he foon found that a fmall quantity of fluid 

 added to it increafed the power; and fucceffive elec- 

 tricians found, that fluid matter, or any conducting 

 body confined in a glafs veflel, had this power of ac- 

 cumulating and condenfing (if I may ufe the expref- 

 fion) the electric virtue. The fliock which an elec- 

 trician is enabled to give by means of the Leyden 

 phial is well known ; and this was foon followed by 



another 



