The second decade of the twentieth century saw a startling intervention into the chloroform debate from the anaesthetist Alfred Goodman Levy. Chloroform is rarely used as an anaesthetic these days, but from late in 1847, when James Young Simpson introduced the agent, until the 1950s it was widely employed. In his textbook of anaesthesia of 1907, Dudley Buxton explained that chloroform was a direct cardiac depressant, an action which, in excess, produced paralysis. Levy's experiments are often designated as 'classic' and the impression can be easily formed that, as Sykes put it, they 'explained the mystery of chloroform death' and 'sealed the fate of chloroform as an anaesthetic'. John Snow described forms of chloroform death. Levy then proposed that chloroform deaths in humans were caused by an identical mechanism; light dosage of chloroform sensitized the heart. Levy's experiments were not originally acclaimed by the anaesthetic community, but by laboratory scientists and clinicians concerned to promote the basic sciences in medicine.