Active in fields spanning medicine, ornithology, zoology and even watercolour painting, Frederick Dawtrey Drewitt (1848–1942) was a prominent fellow of the Royal College of Physicians, exhibited at the Royal Academy, and was involved in governing the National Trust. His particular interest in birds led him to study the work of the physician and naturalist Edward Jenner (1749–1823), who contributed to the field of ornithology through his observations of the cuckoo's behaviour. Jenner is better known, however, as the 'father of immunology' for pioneering the smallpox vaccination - the word 'vaccine' comes from the Latin vacca (cow) as Jenner used the cowpox virus to inoculate against smallpox infection in humans. Drewitt had general readers in mind when he wrote about Jenner's extraordinary life and growing worldwide recognition. The first edition of this biography was published in 1931, and this enlarged second edition appeared in 1933.