Clifford painted a portrait of William M Pryce (1735-1790) that is held by the RCM, Truro. Based on this oil on copper painting J Basire was to create a line engraving, copies of which are in the British Museum and the National Portrait Gallery, and as reproduced in Pryce's Mineralogia Cornubiensis reprints. Pryce was a surgeon, mineralogist and antiquary born at Redruth.
A Pearson (accessed 29 Nov 2010) Dictionary of National Biography [OUP 2004]: Pryce, William
Public Catalogue Foundation (2007) Cornwall & Isles of Scilly: Oil Paintings in Public Collections