2<$z Mr. Bennet’s Defiription, See, 
wax of the infulating nut, but occafionally to ftretch a fingei 
over it to touch the plate, whilft the mahogany handle is held 
ill the fame hand. 
Having found, by repeated experiments, that two clean me- 
tallic plates, or two equally varnifhed plates, rubbed together, 
produced no electricity, I varnifhed the fecond plate gh both 
iides, but more thinly than when one fide only was varnifhed, 
and in fome experiments ufed thimbles on the ends of the 
touching fingers. In this way the inconveniencies of accidental 
friction were in fome meafure obviated, but much lefs than I 
fir ft expected ; for, notwithftanding the utmoft care, eleCtricity 
is produced without previous communication : therefore, in ex- 
periments requiring the eleCtricity to be often doubled, its com- 
munication may yet be afeertained by applying it to the firft 
and fecond plates alternately; fo that pofitive eleCtricity com- 
municated to the firft plate appears pofitive by the electrometer; 
but the fame eleCtricity, applied to the fecond plate whilft the 
firft is touched, produces negative in the electrometer. 
I beg leave to add, that this method of doubling either pofitive 
or negative eleCtricity, as well as M. Volta’s condenfer, with 
Mr. Cavalllo’s improvement on it, as alfo the ingenious experi- 
ments of Father Beccaria with double plates of glafs, which he 
feparated after charging, are all of them to be explained from the 
lame principles with the Leyden bottle, of which they may 
be all faid to be only different applications. I fhall not therefore 
trouble the Society with any further theory on this fubjeCt, but 
proceed to lay before them the diary which I have hitherto 
kept, and during which time I have found no difficulty in col- 
lecting eleCtricity from the atmofphere pofitive or negative, fo 
as to become fufficiently fenfible by the above deferibed appara- 
tus, though the hygrometer has fometimes fhewn the greateft 
degree of moifture. ' > 
Diary 
