th which it
occasions. As most electric machines succeed best after being warmed,
I think even in dry frosty seasons.

Though when a cushion is applied to a smooth surfaced glass, so as to
intermix their electric atmospheres, the vitreous ether of the cushion
is attracted by the resinous ether combined with the glass; but does
not intermix with it, but only adheres to it: and as the glass turns
round, the vitreous electric atmosphere stands on the solid resinous
electric ether combined with the glass; and is taken away by the
metallic points of the prime conductor.

Yet if the surface of the glass be roughened by scratching it with a
diamond or with hard sand, a new event occurs; which is, that the
vitreous ether attracted from the cushion by the resinous ether
combined with the glass becomes adhesive to it; and stands upon the
roughened glass, and will not quit the glass to go to the prime
conductor; whence the surface of the glass having a vitreous electric
atmosphere united, as it were, to its inequalities, becomes similar to
resin; and will now attract resinous electric ether, like a stick of
sealing wax, without combining with it. Whence this curious and
otherwise unintelligible phenomenon, that smooth surfaced glass will
give vitreous electric ether to an insulated conductor, and glass with
a roughened surface will give resinous ether to it.

V. _Accumulation of electric ethers by vicinity._

Though the contact of a cushion on the whirling glass is the easiest
method yet in use for the accumulation of the vitreous electric ether
on an insulated conductor; yet there are other methods of effecting
this, as by the vicinity of the two electric ethers with a
nonconductor between them.

Thus I believe a great quantity of both vitreous and resinous electric
ether may be accumulated in the following manner. Let a glass jar be
coated within in the usual manner; but let it have a loose external
coating, which can easily be withdrawn by an insulating handle. Then
charge the jar, as highly as it may be, by throwing into it vitreous
electric ether; and in this state hermetically seal it, if
practicable, otherwise close it with a glass stopple and wax. When the
external coating is drawn off by an insulating handle, having
previously had a communication with the earth, it will possess an
accumulation of resinous electric ether; and then touching it with
your finger, a spark will be seen, and there will cease to be any
a