E 3 3 
inftruments, capable of producing eleCtri- 
cal phenomena, in a manner at once com¬ 
modious and flriking. At the fame time, 
they examined different eleCtrical fub- 
fiances from which they obtained different 
refults, equally curious and interefting. 
It was very natural to reafonupon, and 
attempt to explain thefe phenomena, and 
very foon different hypothefes were ad¬ 
vanced; of which, thofe of the undiuous 
effluvia, of the vitreous and rejinous , or 
oppofite electricities, and of the pofitive 
and negative electricity, were the princi¬ 
pal, Franklin, who may be confxdered 
as the author of the laft-mentioned theory, 
though it was originally propofed by 
Watfon, explained the eleCtrical pheno¬ 
mena, by its application, in a manner 
much more fatisfaCtory than any others 
had done. This great philofopher carried 
his doCtrine to a very confiderable extent, 
and his followers, as well as thofe who 
B 2 diffented 
