Unpublished manuscript, 'Researches into the identity of the existences or forces light, heat, electricity and magnetism, etc.' by John Goodman Goodman describes the effects that were produced on a moderately sensitive galvanometer by exposure to the Sun’s rays, and which were observed by him during a period of four months, commencing on 14 November 1850. The instrument is described as consisting of 46 turns of covered copper wire, 1/25th of an inch in diameter. The helix is blackened with ink at its southern extremity, and has a single magnetised sewing needle suspended by about sixteen inches of silken fibre in its centre. Includes one figure in the text of the magnetic needle. Annotations in ink throughout. Subject: Physics Received 7 March 1851. Read June 19 1851. Communicated by Thomas Bell. Written by Goodman in Manchester [England]. Whilst the Royal Society declined to publish this paper in full, an abstract of the paper was published in volume 6 of Abstracts of the Papers Printed in the Philosophical Transactions of the Royal Society of London [later Proceedings of the Royal Society] as 'Researches into the identity of the existences or forces, light, heat, electricity and magnetism'. 5 March 1851