Rusian lodestone, 1777 and coil used by Faraday, 1831.
© Science Museum / Science & Society Picture Library
Two items used by the English physicist Michael Faraday (1791-1867). The lodestone belonged to J F Daniell, a contemporary of Faraday and first Profesor of Chemistry at King's College, London. It was used by Faraday in 1831 to produce the first electric spark by electromagnetic induction using a natural magnet. Lodestones are naturally occurring magnets made of magnetite, an iron ore.