A superb long Autograph Letter Signed [to Leone Levi], providing details of the published and unpublished sources of travellers’ accounts, their manuscript notes, rare books, journals, relating to the natural history, geography and economic history of Paraguay, also recommending his own nephew as a reliable and enterprising traveller. 10 pp. 7 x 4 inches, in good condition. St. Leonards on Sea, 15 May 1873. Sir Woodbine Parish (1796-1882), minister at Buenos Ayres, author of ‘Buenos Ayres and the Provinces of Rio de la Plata’ (1839). Leone Levi (1821–1888), jurist, political economist, and statistician, author of the History of British Commerce (1872); Gregorio Benites (1834-1910), Paraguayan diplomat and author, had engaged Levi as his lawyer.