A friend of Charles Darwin and a social activist respected by John Stuart Mill, Alfred R. Wallace (1823–1913) was an outstanding nineteenth-century intellectual. Wallace, renowned in his time as the co-discoverer of natural selection, was a young schoolteacher when he began his exciting career as an explorer-naturalist, and set off for Brazil in 1848 with Henry Walter Bates. A Narrative of Travels on the Amazon and Rio Negro (1853) is the stimulating and engaging result of this first expedition and a precursor to his best-selling Malay Archipelago (1869). The depth and breadth of Wallace's observations in this book as naturalist, anthropologist and geologist are remarkable, and it is tantalising to learn that half his notes and 'the greater part of [his] collections and sketches' were lost at sea when his ship was burned on his voyage home.