thrown open to investigation by the colossal work of
Newton.

THE EXPERIMENTS OF STEPHEN GRAY

In 1729 Stephen Gray (died in 1736), an eccentric and irascible old
pensioner of the Charter House in London, undertook some investigations
along lines similar to those of Hauksbee. While experimenting with a
glass tube for producing electricity, as Hauksbee had done, he noticed
that the corks with which he had stopped the ends of the tube to exclude
the dust, seemed to attract bits of paper and leaf-brass as well as the
glass itself. He surmised at once that this mysterious electricity,
or "virtue," as it was called, might be transmitted through other
substances as it seemed to be through glass.

"Having by me an ivory ball of about one and three-tenths of an inch
in diameter," he writes, "with a hole through it, this I fixed upon a
fir-stick about four inches long, thrusting the other end into the cork,
and upon rubbing the tube found that the ball attracted and repelled
the feather with more vigor than the cork had done, repeating its
attractions and repulsions for many times together. I then fixed the
ball on longer sticks, first upon one of eight inches, and afterwards
upon one of twenty-four inches long, and found the effect the same. Then
I made use of iron, and then brass wire, to fix the ball on, inserting
the other end of the wire in the cork, as before, and found that the
attraction was the same as when the fir-sticks were made use of, and
that when the feather was held over against any part of the wire it
was attracted by it; but though it was then nearer the tube, yet its
attraction was not so strong as that of the ball. When the wire of two
or three feet long was used, its vibrations, caused by the rubbing of
the tube, made it somewhat troublesome to be managed. This put me to
thinking whether, if the ball was hung by a pack-thread and suspended by
a loop on the tube, the electricity would not be carried down the line
to the ball; I found it to succeed accordingly; for upon suspending the
ball on the tube by a pack-thread about three feet long, when the tube
had been excited by rubbing, the ivory ball attracted and repelled the
leaf-brass over which it was held as freely as it had done when it was
suspended on sticks or wire, as did also a ball of cork, and another of
lead that weighed one pound and a quarter."

Gray next attempted to determine what other bodies would attract the
bits of paper, and for this