Born in Sussex, England, Hopkins had a lonely and unhappy childhood. He was brought up by his widowed mother and an unmarried uncle who tended to ignore him. When Hopkins was seventeen, his uncle chose a career in insurance for him and for several years he dutifully gave in to his uncle's wishes. At the same time, however, he also took part-time courses in chemistry at the University of London, eventually getting his degree. In 1888, already twenty-seven years old, Hopkins received the small inheritance that finally enabled him to enter medical school at Guy's Hospital in London.

After getting his doctoral degree in 1894, Hopkins joined the staff of Guy's Hospital and taught for several years. In 1898, he was invited to teach physiology and anatomy at Cambridge University and it was at Cambridge--when Hopkins was well into his thirties--that his long, distinguished career really began.

Hopkins' early research was...