Page:A history of the theories of aether and electricity. Whittacker E.T. (1910).pdf/61

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prior to the Introduction of the Potentials.
41

afluent stream of the same fluid entering the body from outside. Light bodies in the vicinity, being caught in one or other of these streams, are attracted or repelled from the excited electric.

Nollet's theory was in great vogue for some time; but six or seven years after its first publication, its author came across a work purporting to be a French translation of a book printed originally in England, describing experiments said to have been made at Philadelphia, in America, by one Benjamin Franklin. “He could not at first believe," as Franklin tells us in his Autobiography, "that such a work came from America, and said it must have been fabricated by his enemies at Paris to decry his system. Afterwards, having been assured that there really existed such a person as Franklin at Philadelphia, which he had doubted, he wrote and published a volume of letters, chiefly addressed to me, defending his theory, and denying the verity of my experiments, and of the positions deduced from them."

We must now trace the events which led up to the discovery which so perturbed Nollet.

In 1745 Pieter van Musschenbroek (b. 1692, d. 1761), Professor at Leyden, attempted to find a method of preserving electric charges from the decay which was observed when the charged bodies were surrounded by air. With this purpose he tried the effect of surrounding a charged mass of water by an envelope of some non-conductor, e.g., glass. In one of his experiments, a phial of water was suspended from a gun-barrel by a wire let down a few inches into the water through the cork; and the gun-barrel, suspended on silk lines, was applied so near an excited glass globe that some metallic fringes inserted into the gun-barrel touched the globe in motion. Under these circumstances a friend named Cunaeus, who happened to grasp the phial with one hand, and touch the gun-barrel with the other, received a violent shock, and it became evident that a method of accumulating or intensifying the electric power had been discovered.[1]

  1. The discovery was niade independently in the same year by Ewald Georg von Kleist, Dean of Kumpin.