Poisoners from Mary Anne Cotton, the Victorian mass murderess, to Dr Crippen have attracted a celebrity unmatched by violent killers. Secretly administered, often during a family meal, arsenic (the most commonly used poison) led to a slow and agonising death, while strychnine (with its faint smell of almonds) could kill very quickly. Poisoned Lives is the first history of the crime to examine poisoning as a whole. Unwanted husbands, wives or lovers, illegitimate babies, children killed for the insurance money, relatives, rivals and employers were amongst the many victims. Difficult to detect before 1800, poison undoubtedly had its heyday in the nineteenth century. In response to many suspected cases, forensic tests were developed that made detection increasingly likely. The sale of poisons also became much more tightly controlled. Because of this, twentieth-century poisoning became a crime carried out largely by professionals, notably doctors and nurses, including Harold Shipman and Beverley Allitt.