268 Mr . Nicholson’s Experiments and 
ftronger the adion of the cufhion, as judged by the eledricity 
on the cufhion fide. 
Hence it follows, that the internal furface of a cylinder Is 
o far from being difpofed to give out eledricity during the 
fridion by which the external furface acquires it, that it even 
greedily attrads it. 
13. A plate of glafs was applied to the revolving plate, and 
thruft under the cufhion in fuch a manner as to fupply the 
place of the filk flap. It rendered the eledricity ftronger, and 
appears to be an improvement of the plate machine ; to be 
admitted if there were not effential objedions againft the ma- 
chine itfelf. 
14. Two cufhions were then applied on theoppofite furfaces 
with their filk flaps, fo as to clafp the plate between them. The 
eledricity was received from both by applying the finger and 
thumb to the oppofite furfaces of the plate. When the finger 
was advanced a little towards its correfpondent cufhion, fo 
that its diftance was lefs than between the thumb and its 
cufhion, the finger received ftrong eledricity, and the thumb 
none ; and, contrariwife, if the thumb were advanced beyond 
the finger, it received all the eledricity, and none parted to the 
finger. This eledricity was not ftronger than was produced by 
the good adion of one cufhion applied fingly. 
15. The cufhion in experiment 12. gave mo ft eledricity 
when the back furface was fupplied, provided that furface was 
fufFered to retain its eledricity till the rubbed furface had given 
out its eledricity. 
From the two laft paragraphs it appears, that no advantage 
is gained by rubbing both furfaces ; but that a well managed 
fridion on one furtace will accumulate as much eledricity as 
the prefent methods of excitation feem capable of colleding ; 
but 
