304 STWy ofM. Du F [Book III. 



thefe and other dccifive experiments Dr. Wat Ton con- 

 cludes, that thefe globes and tubes are no more than 

 the firit movers or determiners of the electric power. 



M. Du Fay had made a diftinction of two dif- 

 ferent fpecies of electricity, one of which he called the 

 vitreous, and the other the refmous electricity ; and foon 

 after the difcovery of the Leyden phial, it was found, 

 that by coating the outfide of the phial with a conduct- 

 ing lubftance, which communicated by a wire with 

 the perfon who difcharged the phial, the fhock was 

 immenfely increafed ; and indeed it appeared, that the 

 phial could not be charged unlefs fome conducting 

 N lubfrance was in contact with the outfide. Dr. Frank- 

 lin, however, was the firft who explained thefs pheno- 

 mena. He fhewed that the furplus of electricity, 

 which was received by one of the coated furfaces of 

 the phial, was actually taken from the other ; and that 

 one was poTefTecl of lefs than its natural fhare of the 

 electric matter, while the other had a fuperabundance. 

 Thefe two different dates of bodies, with refpect to 

 their portion of electricity, he diftinguifhed by the 

 terms plus or pofitive, and minus or negative j and it 

 was inferred from the appearances, that bodies which 

 exhibited what M. Du Fay called the refinous electri- 

 city, were in the ftate of minus, that is, in the ftate of 

 attracting the electic matter from other bodies, while 

 thofe which were podefied of the vitreous electricity 

 were bodies electrified plus, or in a itate capable of 

 imparting electricity to other bodies. By this difco- 

 very Dr. Franklin was enabled no increafe the electric 

 power almofl: at pleafure, namely, by connecting the 

 outfide of one phial with the infide of another, in fuch 

 a manner that the fluid which was driven out of the 

 firft would be received by the fecond, and what was 

 driven out of the fecond would be received by the 



' third, 



