Page:A history of the theories of aether and electricity. Whittacker E.T. (1910).pdf/62

This page has been proofread, but needs to be validated.
42
Electric and Magnetic Science

Shortly after the discovery of the Leyden phial, as it was named by Nollet, had become known in England, a London apothecary named William Watson (b. 1715, d. 1787)[1] noticed that when the experiment is performed in this fashion the observer feels the shock "in no other parts of his body but his arms and breast"; whence he inferred that in the act of discharge there is a transference of something which takes the shortest or best-conducting path between the gun-barrel and the phial. This idea of transference seemed to him to bear some similarity to Nollet's doctrine afflux and efflux; and there can indeed be little doubt that the Abbé's hypothesis, though totally false in itself, furnished some of the ideas from which Watson, with the guidance of experiment, constructed a correct theory. In a memoir[2] read to the Royal Society in October, 1746, he propounded the doctrine that electrical actions are due to the presence of an "electrical aether," which in the charging or discharging of a Leyden jar is transferred, but is not created or destroyed. The excitation of an electric, according to this view, consists not in the evoking of anything from within the electric itself without compensation, but in the accumulation of a surplus of electrical aether by the electric at the expense of some other body, whose stock is accordingly, depleted All bodies were supposed to possess a certain natural store, which could be drawn upon for this purpose.

"I have shewn," wrote Watson, "that electricity is the effect of a very subtil and elastic fluid, occupying all bodies in contact with the terraqueous globe; and that every-where, in its natural state, it is of the same degree of density; and that glass and other bodies, which we denominate electrics per se, have the power, by certain known operations, of taking this fluid from one body, and conveying it to another, in a quantity sufficient to be obvious to all our senses; and that, under

  1. Watson afterwards rose to eminence in the medical profession, and was knighted
  2. l'hil. Trans. xliv.. p, 718. It may here be noted that it was Watson who improved the phial by coating it nearly to the top, both inside and outside, with tinfoil.