Dr John Percy (1817–89) was a metallurgist, the author of the four-volume A Treatise on Metallurgy, and an amateur artist who collected watercolours, drawings and prints (Feather, 2014, pp.193–208). A sale of his 'very valuable and extensive collection of Water-Colour drawings ...comprising upward of fifteen hundred drawings by nearly seven hundred painters of the English Water-Colour School, and forming an almost complete history of water-colour art from the commencement of the eighteenth century to the present time' was held at Christie's in 1890 (15–18 and 22–24 April) and his collection of prints was sold at Sotheby’s in the same year (12–13 May 1890). The former included thirty-five items by or attributed to Girtin (Exhibitions: Christie's, 17 April 1890; Christie's, 23 April 1890). The informative manuscript catalogue he compiled of his collection is in the Department of Prints and Drawings at the British Museum (Percy Catalogue) interleaved in a copy of the pioneering 1871 exhibition of watercolours organised by the Burlington Fine Arts Club.