Chapter I

, and Priestley, “History,” etc., s. 5). The paper containing an account of Canton’s experiments was read before the Royal Society, December 6, 1753. The principle enounced is that “the electric fluid, when there is a redundancy of it in any body, repels the electric fluid in any other body when they are brought within the sphere of each other’s influence and drives it into the remote parts of the body; or quite out of it, if there be any outlet for that purpose. In other words, bodies immerged in electric atmospheres always become possessed of the electricity contrary to that of the body in whose atmosphere they are immerged.”

Canton is the first to show that the air of a room can be electrified either positively or negatively, and can be made to retain the electricity when received. He thus explains his method: “Take a charged phial in one hand and a lighted candle insulated in the other, and, going into any room, bring the wire of the phial very near to the flame of the candle and hold it there about half a minute, then carry the phial and candle out of the room and return with the pith balls (suspended by fine linen threads) held out at arm’s length. The balls will begin to separate on entering the room and will stand an inch and a half or two inches apart when brought near the middle of it.”

The construction of artificial magnets by Canton, through the combination of the Duhamel (A.D. 1749) and the Michell (A.D. 1750) methods, as well as without the aid of natural loadstones or artificial magnets, is detailed by Noad at