He was born in Bromfield, Shropshire, the seventh of thirteen children, the son of a tenant farmer. He matriculated at Edinburgh University 1 November 1819, and was admitted as a Member of the Royal College of Surgeons in London 5 May 1820: he was 21 months under age, according to the regulations. He married to Eliza Hannah Gardner of Leigh Court, near Worcester, on 29 May 1821, and set up practice in Ludlow, probably at the beginning of that year.
It was from Ludlow on 21 February 1824 that he wrote to T.A. Knight of Downton Castle, claiming to have performed experiments on animals showing that surgery could be carried out painlessly and successfully while the subjects were in a state of what he called suspended animation. Knight was one of the presidents of the Royal Society, and when Hickman reprinted this letter as a pamphlet, on the title page the words 'and read before it by Sir Humphrey Davy' are crossed out in ink. It has been suggested that Knight and Davy were both at first enthusiastic, but that Davy then had second thoughts, possibly because of an anti-vivisectionist lobby within the Royal Society. There were critical reviews of the pamphlet in The Gentleman's Magazine and The Lancet in 1826.
Hill did not give up, and in 1828 went to Paris and presented a paper to Charles X: this was forwarded to the Academie Royale de Medicine and a committee set up to look into his proposals that painless surgical operations could be performed on humans: this came to nothing. On his return from Paris, Hickman moved to Tenbury, where he set up practice: he died nine months later, and was buried in Bromfield Churchyard, April 5th 1830. His house in Teme Street in Tenbury is still there, now a restaurant.
Hickman's suspended animation had a serious flaw: rather than nitrous oxide he used carbon dioxide, which in small quantities leads to unconsciousness, but in larger quantities leads to death. His proposals were 20 years ahead of the first use of anaesthesia: in Great Britain James Simpson introduced chloroform anaesthesia in 1847.
Acknowledgments: George Price, Country Restaurant, Tenbury Wells Dr. J.A. Burnett, MRCS LRCP DA
Further reading: W.D.A. Smith Henry Hill Hickman MRCS (1800-1830) and Anaesthesia (Univ. of Leeds 1981)