WILLIAM GILBERT. 6 1 



a pin. This apparatus, termed by him a versormm, constituted the 

 electroscope, by the aid of which he disproved the idea that the 

 alleged magical property was possessed only by amber or by jet. He 

 poured out the vials of his wrath upon the empty-headed and inert 

 philosophers who merely copy from one another and invent high- 

 sounding Greek words wherewith to cloak their ignorance. " For 

 not only do amber and jet, as they say, draw light bodies, but 

 diamond, sapphire, carbuncle, cat's-eye, opal, amethyst, vincentina 

 and bristolla (an English gem or spar), beryl and rock crystal do the 

 same." And he went on enumerating a host of other substances 

 possessing similar powers, following up the true gems with false gems 

 made from paste, glass of antimony, slags, belemnites, sulphur, 

 mastic, hard wax, sealing wax variously coloured, resin and arsenic, 

 and also, but less powerfully and only in dry weather, rock salt, 

 obsidian, and rock alum. All these substances, because they 

 resembled amber, he termed electrics ; whilst he gave the name of 

 cinelcctrics to another class of substances which showed no such 

 power, and which included the following : Emerald, agate, cornelian, 

 pearls, jasper, alabaster, porphyry, coral, marble, flint, haematite, 

 emery, bone, ivory, ebony and other hard woods, cedar, gold, copper, 

 iron, and the other metals, and, lastly, the loadstone. The substance 

 which above all others possesses the magnetic property of attracting 

 iron shows no trace of electric action when rubbed in the hand. 

 From the terms assigned by Gilbert, the word electricitas — electricity — 

 came into use to denote the unseen agent operating in these actions. 

 Gilbert further showed that the power of attraction exercised by the 

 electric when rubbed was not limited to mere straws or chaff, but 

 that all metals and woods, and even stones and earths were attracted. 

 He even found that liquids, oil and water were drawn by the electric 

 force. He ascertained that moisture exercises a prejudicial effect on 

 electrical experiments. He observed that electrical effects can be 

 screened off, and in a way that magnetic effects cannot, by the inter- 

 position of a sheet of metal, or even by a piece of paper. He even 

 ascertained the screening effect of a ring of flames. His 

 observations stop short all too soon, leaving the infant science 

 truly in a state of infancy. Nevertheless he was the pioneer whose 

 first steps showed the path to be latter trodden by Robert 

 Boyle, by Francis Hauksbee, by Sir Isaac Newton, and by Benjamin 

 Franklin ; and therefore is beyond dispute the father of electric 

 science. 



