THUNDER STORMS. 85 
fides as they were placed at firft, with a good conductor 
introduced between them, which will anfwer the fame pur- 
pofe, and be attended with an explofion, or {mart {park 
and fnap; or laftly, to place it in a fituation where it may 
be expofed to air replete with moift vapors, where, after 
fome time, the vapors will, by condenfing upon each fide, 
furnifh it with a moifture equivalent to a non-electric coat- 
ing, while the vapors which remain in the furrounding 
air will, by continually impinging upon and receding from 
the two furfaces, at length reftore both to their natural 
fate. 
It is evident from the foregoing experiment, Firff, That 
the charges refide in the glafs itfelf, as they remain after 
the coatings are removed. Secondly, That the oppofite fides 
hhave a very ftrong propenfity, one to give, the other to re- 
ceive the fluid, and thereby to reftore the electric equili- 
brium between themfelves; which is done with violence, 
as obferved above, when they are put in a condition of do- 
ing it by the reapplication of the metalline coatings, with 
a conductor between them, and La/fly, That notwithftand- 
ing the violent propenfity in the fides of the glafs, to re- 
ftore themfelves and each other to their natural electric 
ftates, and the {mall diftance between them, they can ne- 
ver effect it, without the intervention of non-electric con- 
ductors. 
2. I thall now fhew by other experiments, that different 
regions or ftrata of air may become charged, both pofi- 
tively and negatively, in the fame manner as the fides of 
the pane of glafs were in the foregoing; and that the 
effects of fuch charges are precifely the fame. 
Mefirs Wilkie and A’pinus at Berlin, having the hint 
naturally fuggefted to them by a previous courfe of experi- 
ments, endeavoured to give the electrical fhock by means 
of air, in the fame manner-in which it may be given by 
gla/*; “im which after making feveral attempts (fays doc 
“ tor Prieftley*) they at length fucceeded, by fufpending 
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