Page:A history of the theories of aether and electricity. Whittacker E.T. (1910).pdf/57

 repels light Bodies. The smallest parts of the glass are agitated by the Attrition, and by reason of their elasticity, their motion is vibratory, which is communicated to the Atmosphere above-mentioned: and therefore that Atmosphere exerts its action the further, the greater agitation the Parts of the Glass receive when a greater attrition is given to the glass."

The English translator of s'Gravesando's work was himself destined to play a considerable part in the history of electrical science. Jean Théophile Desaguliers (b. 1683, d. 1744) was an Englishman only by adoption. His father had been a Huguenot pastor, who, escaping from France after the revocation of the Edict of Nantes, brought away the boy from La Rochelle, concealed, it is said, in a tub. The young Desaguliers was afterwards ordained, and became chaplain to that Duke of Chandos who was so ungratefully ridiculed by Lope. In this situation he formed friendships with some of the natural philosophers of the capital, and amongst others with Stephen Gray, an experimenter of whom little is known beyond the fact that he was a pensioner of the Charterhouse.

In 1729 Gray communicated, as he says, "to Dr. Desaguliers and some other Gentlemen” a discovery he had lately made, "showing that the Electrick Vertue of a Glass Tube may be conveyed to any other Bodies so as to give them the same Property of attracting and repelling light Bodies as the Tube does, when excited by rubbing: and that this attractive Vertue might be carried to Bodies that were many Feet distant from the Tube."

This was a result of the greatest importance, for previous workers had known of no other way of producing the attractive emanations than by rubbing the body concerned. It was found