FARADAY, MICHAEL, English chemist and physicist. Autograph letter signed ("M Faraday") to Reverend Buckland, regarding the properties of a stone given to him by the Reverend. [London] "Royal Institution," 20 August 1831. One page, small 4to, integral leaf addressed by him and with wax seal, postmarked, a few tears along folds, some light soiling, matted and framed with an engraved portrait.