Chap, i.] Dr. Franklin. 30$ 



third, &c. and this conftitutes what we now call an 

 electrical battery. 



But the mofl aftonifhing difcovery which Franklin, 

 or I might fay any other perfon, ever made in this 

 branch of fcience, was the demonftration of what had 

 been (lightly fufpected by others, the perfect fimilarity, 

 or rather identity, of lightning and electricity. The 

 Doctor was led to this difcovery by comparing the 

 effects of lightning with thofe of electricity, and by re- 

 flecting, that if two gun- barrels electrified will ftrike at 

 two inches, and make a loud report, what muft be 

 the effect of ten thoufand acres of electrified cloud. 

 Not fatisfied, however, with {peculation, he conftructed 

 a kite with a pointed wire fixed upon it, which, during 

 a thunder ftorm, he contrived to fend up into an 

 electrical cloud. The wire in the kite attracted the 

 lightning from the cloud, and it defcended along the 

 hempen firing, and was received by a key tied to the 

 extremity of it, that part of the firing which he held 

 in his hand being of filk, that the electric virtue might 

 Hop when it came to the. key. At this key he charged 

 phials, and from the fire thus obtained he kindled 

 fpirits, and performed all the common electrical ex- 

 periments. 



Dr. Franklin, after this difcovery, conftructed an 

 infulated rod to draw the lightning from the atmo- 

 fphere into his houfe, in order to enable him to make 

 experiments upon it ; he alfo connected with it two 

 bells, which gave him notice by their ringing when 

 his rod was electrified. This was the origin of the 

 metallic conductors now in general ufe. 



It was afterwards difcovered by Mr. Canton, that 

 the pofitive and negative electricity, which were fup- 

 pofed to depend upon the nature of the excited body, 

 and therefore had obtained the namejs of refmous and 



VOL. I. X vitreous, 



