'Cuprum sulphuratum' Size:XS: 40 x 30cm His right hand holds a

His right hand holds a pen poised over a sheet of paper on a table to the left of the picture as viewed

26 October 1965

11th November 1974

View of Charles Street with figures working in the foreground

Specimen termed 'Arseniate of copper' with two details of crystals

'Cuprum sulphuratum' Size:XS: 40 x 30cm His right hand holds aSpecimens of copper sulphate, here termed 'sulphuret of copper', with a figure showing its crystalline form. Plate 77 from British mineralogy: or coloured figures intended to elucidate the mineralogy of Great Britain, by James Sowerby, volume 1 (London, R. Taylor & Co., 1804). The accompanying text states that 'This copper ore is not uncommon; but the form of the crystallization in this specimen is either rare, or has been hitherto overlooked