pressed upon the surface of a glass
cylinder or plane, the atmosphere of the cushion is forced within that
of the glass, and consequently the vitreous part of it is brought
within the sphere of the attraction of the resinous ether combined
with the glass, and therefore becomes attracted by it in addition to
the vitreous part of the spontaneous atmosphere of the glass; and the
resinous part of the atmosphere of the cushion is at the same time
repelled by its vicinity to the combined resinous ether of the glass.
From both which circumstances a vitreous ether alone surrounds the
part of the glass on which the cushion is forcibly pressed; which does
not, nevertheless, resemble an electrised coated jar; as this
accumulation of vitreous ether on one side of the glass is not so
violently condensed, or so forcibly attracted to the glass by the
loose resinous ether on the other side of it, as occurs in the charged
coated jar.

Hence as weak differences of the kinds or quantities of electricity do
not very rapidly change place, if the cushion be suddenly withdrawn,
with or without friction, I suppose an accumulation of vitreous
electric ether will be left on the surface of the glass, which will
diffuse itself on an insulated conductor by the assistance of points,
or will gradually be dissipated in the air, probably like odours by
the repulsion of its own particles, or may be conducted away by the
surrounding air as it is repelled from it, or by the moisture or other
impurities of the atmosphere. And hence I do not suppose the friction
of the glass-globe to be necessary, except for the purpose of more
easily removing the parts of the surface from the pressure of the
cushion to the points of the prime conductor, and to bring them more
easily into reciprocal contact.

When sealing wax or sulphur is rubbed by a cushion, exactly the same
circumstance occurs, but with the different ethers; as the resinous
ether of the spontaneous atmosphere of the cushion, when it is pressed
within the spontaneous atmosphere of the sealing wax, is attracted by
the solid vitreous ether, which is combined with it; and at the same
time the vitreous ether of the cushion is repelled by it; and hence an
atmosphere of resinous ether alone exists between the sealing wax and
the cushion thus pressed together. It is nevertheless possible, that
friction on both sealing wax and glass may add some facility to the
accumulations of their opposite ethers by the warm