Professor John Anthony Henry (Born: 11 March 1939 at Greenwich, England, died 8 May 2007) was a professor specialising in toxicology in the Faculty of Medicine, Imperial College London, at St Mary's Hospital in Paddington. He conducted research on the health effects of cannabis, cocaine and other recreational drugs.
Thomas Stevenson (1838 – 18 January 1908) was an English toxicologist and forensic chemist. He served as an analyst to the Home Office and in England he served as an expert witness in many famous poisoning cases. These included the Pimlico Mystery, The Maybrick Case, the Lambeth Poisoner, and the George Chapman case.