[17] This power of points to _throw off_ the electrical fire, was
first communicated to me by my ingenious friend Mr. Thomas Hopkinson,
since deceased, whose virtue and integrity, in every station of life,
public and private, will ever make his memory dear to those who knew
him, and knew how to value him.
[18] This was Mr. Hopkinson's experiment, made with an expectation
of drawing a more sharp and powerful spark from the point, as from a
kind of focus, and he was surprised to find little or none.
[19] We suppose every particle of sand, moisture, or smoke, being
first attracted and then repelled, carries off with it a portion
of the electrical fire; but that the same still subsists in those
particles, till they communicate it to something else, and that it is
never really destroyed. So when water is thrown on common fire, we do
not imagine the element is thereby destroyed or annihilated, but only
dispersed, each particle of water carrying off in vapour its portion
of the fire, which it had attracted and attached to itself.
[20] This different effect probably did not arise from any difference
in the light, but rather from the particles separated from the
candle, being first attracted and then repelled, carrying off the
electric matter with them; and from the rarefying the air, between
the glowing coal or red-hot iron, and the electrised shot, through
which rarefied air the electric fluid could more readily pass.
[21] These experiments with the wheels, were made and communicated
to me by my worthy and ingenious friend Mr. Philip Syng; but we
afterwards discovered that the motion of those wheels was not owing
to any afflux or efflux of the electric fluid, but to various
circumstances of attraction and repulsion. 1750.
[22] By taking a spark from the wire, the electricity within the
bottle is diminished; the outside of the bottle then draws some from
the person holding it, and leaves him in the negative state. Then
when his hand or face is touched, an equal quantity is restored to
him from the person touching.
[23] Our tubes are made here of green glass, 27 or 30 inches long, as
big as can be grasped.
[24] This simple easily-made machine was a contrivance of Mr. Syng's.