William Cullen (1710–1790) was the greatest teacher of clinical medicine in Britain in the 18th century. He was born in Hamilton in Lanarkshire and began his career in Glasgow where he held the chair of chemistry and was one of the founders of the medical school. In 1755 he moved to Edinburgh with its already flourishing medical school and its new hospital, the Royal Infirmary, and there he held in succession the chairs of chemistry, the institutes (theory) of medicine and the practice of physic. Together with Alexander Monroe he made Edinburgh the most famous medical school in the Western world and students came from far and wide to be taught by him – from England, Scotland and Ireland, from the Americas and the West Indies and from the Continent. Like Boerhaave, his reputation rested mainly on his gifts as a teacher and it is clear that his students idolised him. Benjamin Rush, the founder of the first medical school in the New World in Philadelphia, America's first psychiatrist and one of the signatories of the American Declaration of Independence, wrote of him that “It is scarcely possible to do justice to this great man's Character either as a scholar, a physician, or a Man”.