The concept of drug receptors has played a significant role in the biomedical sciences and in pharmaceutical innovation in the second half of the twentieth century. Although the concept dates back to the work of the German bacteriologist and immunologist Paul Ehrlich and of the British physiologist John Newport Langley at the end of the nineteenth and the beginning of the twentieth century, its acceptance was delayed because of conflicting ideas about drug action, and because of uncertainties and hesitations about the concept itself.

Historical myths die hard: one such is of a supposed outbreak of scurvy—said by some to be the result of medical insouciance—at Millbank penitentiary in 1823. Thus, Sean McConville in his masterly account of prisons in the reform period writes: “The decision [to reduce the diet] was a major factor in the scurvy epidemic which followed shortly afterwards, causing at least thirty deaths”. Other authors take a similar line: “Fifteen months later, after 30 had died, and after the whole convict population had been evacuated from the prison, Holford was convinced that the disease had been sea-scurvy”; “there was a serious outbreak of scurvy not long after the new diet was adopted”; “In the winter of 1823, the inmates began to succumb to typhus, dysentery, and scurvy. Thirty-one died and four hundred others were incapacitated”; “The scurvy was the prevailing disease, and was seen in over half of the 860 inmates”. Joe Sim in his generally condemnatory evaluation of medical staff working in prisons states: “Millbank was at the centre of a major controversy when an outbreak of scurvy occurred and thirty-one prisoners died. The [Prison Medical Service] was deeply implicated”, and he goes on to associate the physician in charge with “experiments” on the bodies and minds of the confined.

This article contributes to the literature on the history of medico-legal practice by using a survey of 535 poisoning cases to examine the emergence of forensic toxicological expertise in nineteenth-century English criminal trials. In emphasizing chemical expertise, it seeks both to expand upon a limited literature on the history of the subject, and to offer a contrast to studies of criminal poisoning that have tended to focus primarily on medical expertise. Poisoning itself is a topic of abiding interest to historians of forensic medicine and science because (together with insanity) it long tended to attract the greatest attention (and often confrontation) in criminal proceedings. In looking at a wide number of cases, however, it becomes apparent that few aroused true medico-legal controversy. Rather, the evidence from several hundred cases tried as felonies during the eighteenth and nineteenth centuries indicates that prior to the 1830s few presented any opportunity for “a battle of experts”. While Ian Burney and Tal Golan have shown that this was certainly not the case during the mid and late nineteenth century, this paper goes further by dividing the period under study into three distinct phases in order to show how expert testimony (and experts themselves) changed during the course of the century, and why this process opened a door to the potential for formalized controversy.