ctrical matter which had hitherto escaped the notice of
electricians. He also made the grand discovery of a plus and minus, or
of a positive and negative, state of electricity. We give him the honor
of this without hesitation; although the English have claimed it for
their countryman, Dr. Watson. Watson's paper is dated January 21, 1748;
Franklin's, July 11, 1747, several months prior. Shortly after Franklin,
from his principles of the plus and minus state, explained in a
satisfactory manner the phenomena of the Leyden vial, first observed by
Mr. Cuneus, or by Professor Muschenbroeck, of Leyden, which had much
perplexed philosophers. He showed clearly that when charged the bottle
contained no more electricity than before, but that as much was taken
from one side as was thrown on the other; and that to discharge it
nothing was necessary but to produce a communication between the two
sides, by which the equilibrium might be restored, and that then no sign
of electricity would remain. He afterward demonstrated by experiments
that the electricity did not reside in the coating, as had been
supposed, but in the pores of the glass itself. After a vial was charged
he removed the coating, and found that upon applying a new coating the
shock might still be received. In the year 1749 he first suggested his
idea of explaining the phenomena of thunder-gusts and of the aurora
borealis upon electrical principles. He points out many particulars in
which lightning and electricity agree, and he adduces many facts, and
reasonings from facts, in support of his positions.

"In the same year he received the astonishingly bold and grand idea of
ascertaining the truth of his doctrine by actually drawing down the
lightning, by means of sharp-pointed iron rods raised into the region
of the clouds. Even in this uncertain state his passion to be useful to
mankind displayed itself in a powerful manner. Admitting the identity of
electricity and lightning, and knowing the power of points in repelling
bodies charged with electricity, and in conducting their fires silently
and imperceptibly, he suggested the idea of securing houses, ships,
etc., from being damaged by lightning, by erecting pointed rods that
should rise some feet above the most elevated part, and descend some
feet into the ground or water. The effect of these he concluded would be
either to prevent a stroke by repelling the cloud beyond the striking
distance, or by drawing off the electr