M. Faraday.
The reference at the beginning of this letter to the chlorides of carbon has to do with his discovery communicated to the Royal Society. Later in the year, a joint paper on another compound of carbon and chlorine, by himself and his friend Richard Phillips, was sent in. Both were printed together in the Philosophical Transactions of 1821.
LEAVES FROM THE NOTE-BOOK.
The following is an extract from Faraday’s laboratory book relating to the discovery. The account is incomplete, a leaf having been torn out:—
1821, Sept. 3.
The effort of the wire is always to pass off at a right angle from the pole, indeed to go in a circle round it, so when either pole was brought up to the wire perpendicular to it and to the radius of the circle it described, there was neither attraction nor repulsion, but the moment the pole varied in the slightest manner either in or out, the wire moved one way or the other.
The poles of the magnet act on the bent wire in all positions and not in the direction only of any axis of the magnet, so that the current can hardly be cylindrical or arranged round the axis of a cylinder?
From the motion above a north magnet pole in the centre of one of the circles should make the wire continually turn round. Arranged a magnet needle in a glass tube with mercury about it, and by a cork, water, &c., supported a connecting wire so that the upper end should go into the silver cup and its mercury, and the lower move in a channel of mercury round the pole of the needle. The battery arranged with the wire as before. In this way got the revolution of the wire round the pole of the magnet. The direction was as follow, looking from above down:—
Fig. 2. (Facsimile of Original Sketch.)