Willis, Thomas (1621–1673)

English physician and a founding member of the Royal Society who contributed much to our knowledge of the nervous system and cardiovascular system. He carried out a detailed study of the circulation of the brain, including the cerebral arterial circle, which he discovered under the base of the brain, that bears his name.

Willis wrote extensively about many diseases, including the mental disorders hypochondria, hysteria, and melancholia. He rediscovered the sweetness of urine excreted from patients with diabetes mellitus (which had originally been identified by physicians in India around 400 BC).