within had not the
least power to communicate a further charge to it. If any portion of the
air was electrified, as glass or other insulators may be charged (1171.),
it was accompanied by a corresponding opposite action _within_ the cube,
the whole effect being merely a case of induction. Every attempt to charge
air bodily and independently with the least portion of either electricity
failed.

1174 I put a delicate gold-leaf electrometer within the cube, and then
charged the whole by an _outside_ communication, very strongly, for some
time together; but neither during the charge or after the discharge did the
electrometer or air within show the least signs of electricity. I charged
and discharged the whole arrangement in various ways, but in no case could
I obtain the least indication of an absolute charge; or of one by induction
in which the electricity of one kind had the smallest superiority in
quantity over the other. I went into the cube and lived in it, and using
lighted candles, electrometers, and all other tests of electrical states, I
could not find the least influence upon them, or indication of any thing
particular given by them, though all the time the outside of the cube was
powerfully charged, and large sparks and brushes were darting off from
every part of its outer surface. The conclusion I have come to is, that
non-conductors, as well as conductors, have never yet had an absolute and
independent charge of one electricity communicated to them, and that to all
appearance such a state of matter is impossible.

1175. There is another view of this question which may be taken under the
supposition of the existence of an electric fluid or fluids. It may be
impossible to have one fluid or state in a free condition without its
producing by induction the other, and yet possible to have cases in which
an isolated portion of matter in one condition being uncharged, shall, by a
change of state, evolve one electricity or the other: and though such
evolved electricity might immediately induce the opposite state in its
neighbourhood, yet the mere evolution of one electricity without the other
in the _first instance_, would be a very important fact in the theories
which assume a fluid or fluids; these theories as I understand them
assigning not the slightest reason why such an effect should not occur.

1176. But on searching for such cases I cannot find one. Evolution by
friction, as is well known, gives both powers in