Obfervations in Electricity. 1 1 5 
fore uniformly aCted as reprefented in my paper. At 
length I recollected, that this experiment had been made 
rather more expeditiouily than ufual: I therefore re- 
peated it, and having allowed fomewhat more time be- 
tween the removal of the plates from the prime con- 
ductor, and the feparation of them, in order to examine 
their electricity, I found on each plate a pofitive and a 
negative furface; and having replaced them and made 
the difcharge, I obferved that the electricity of all the 
furfaces was changed. I have mentioned this circum- 
ftance, to fhew how fmall a difference in the manner of 
making an experiment, will make an effential difference 
alfo in the refult. There is fomething, however, very 
lingular in this kind of glafs, which I believe is owing to 
its not being properly annealed ; for I once met with a 
plate of it which I found very difficult to charge at all ; 
and when a fmall quantity of electricity had been forced 
into it, it diffipated proportionably fooner, without the 
ufe of the difcharging rod. 
In glafs, properly annealed, whether in the form of 
plates or jars, prepared for the Leyden experiment, the 
diffipation of the electricity is, in forne Hates of the atmo- 
fphere, a remarkable, and fometimes (when there is not 
a fire in the room) a difagreeable circumftance : this ef- 
fect, however, in the jar itfelf, may be in a great mea- 
fure prevented, by having the uncoated part of the glals 
Q 2 neatly 
