Royal Society, London, Miscellaneous correspondence vol. 16, 1889-92, letter no. 31.This letter is filed with one of M's calling cards and a three-page printed document, with handwritten additions by M, headed 'Liber Baro Fedinandus De Mueller' and dated 20 June 1892, listing, in Latin, all M's degrees, awards, honours and society memberships, presumably sent as an enclosure with this letter. See the file ‘Titles and memberships’ in this edition