While Thomas Beddoes is mainly remembered as the sponsor of Humphry Davy and as a friend of Samuel Taylor Coleridge, his career as a medical doctor was shaped by strong democratic principles and a vigorous interest in medical experiment and reform. As a student of the mind, he was a follower of the empiricism of John Locke and David Hartley. Beddoes was an accomplished chemist, familiar with the latest advances in Europe as well as England. Although he made no new discoveries in this area, he put his chemical knowledge to good use in his medical experiments. In medical history he is known as the founder of the Pneumatic Institution at Clifton in Bristol, opened in 1798. There Beddoes undertook the first systematic attempts to study the effects of respiring different gases on human and animal subjects. He was assisted by James Watt, who manufactured the machinery for producing...