Revd. Gilbert White published his revolutionary Natural History of Selborne in 1789, an entirely new insight into the natural world. John Knapp was the first to follow White's successful format, publishing his Journal of a Naturalist anonymously in 1829. Knapp's work was an instant success and ran into four editions in Britain. It was twice pirated in America. Knapp's Journal, based on his observations in Alveston in southern Gloucestershire, his childhood home in Buckinghamshire and a brief sojourn in Monmouthshire, reignited early 19th-century popular enthusiasm for nature. His death in 1845 however prevented publication of a greatly enlarged fifth edition of his work. For this biography, Knapp's remarkable life has not only been researched in depth and described for the first time, but by using Knapp's original hand-written notes, the author has been able to re-create the previously unpublished fifth edition of the Journal and present it here in full.