Thomas Willis, physician, 1742. Artist: George Vertue

Thomas Willis, physician, 1742. To the left of his portrait are parts of a skull and a diagram of the spine and ribcage. To the right are several books, one open at a page to show a particular diagram. Willis was the first to distinguish the form of diabetes known as 'diabetes mellitus' and carried out pioneering studies into the anatomy of the brain. He also worked on diseases of the nervous system and muscles and became professor of natural philosophy at Oxford in 1660. He was also founder of the Royal Society. (Photo by Oxford Science Archive/Print Collector/Getty Images)