An old superstition claims that a murderer's presence will make a victim's corpse bleed, thereby offering proof of guilt. As Ian Burney explains in his study of the relationship between science and law, this expectation that the dead could speak reemerged in nineteenth-century Britain: thanks to developments in toxicology, corpses could be made to reveal their death by criminal poisoning, and poisoners who might otherwise have got away with murder could be prosecuted.

Burney's study demonstrates how this expectation was both upheld and undone by the events of midcentury. He takes as his lens the infamous 1856 murder trial of William Palmer, a doctor with a predilection for gambling and racehorses, and through it views a diversity of complex cultural developments that shaped the legal, medical, and cultural landscape of the Victorian era. He examines the public and scientific discourses surrounding poisoning, tracing how they became shaped into the particular myths and misconceptions of the Victorian era, and from which toxicology had to pull itself free. He explores the refinement of medical jurisprudence at a time when prosecutions for criminal poisonings were greater in number and higher in profile than ever before. As he demonstrates, trying to contain the threats posed by poisoning was fraught with difficulties. Indeed, even defining what constituted a poison proved problematic—many substances, including medicines and common salt, were toxic when taken in sufficient quantity.

Palmer makes for a rewarding subject for a study of this kind. Although he was convicted and hanged for the murder of his associate, John Parsons Cook, sufficient doubt hung over the case that many, even in the medical community, hoped that he would make a last-minute confession. The canny Palmer did not—indeed, his pronouncement just before his execution that “I am innocent of poisoning Cook by strychnine” (1) frustrated more than it clarified. Strychnine had been named as the poison used in Cook's murder, but no material trace of it had been found. Despite the many other indicators of Palmer's guilt, without this evidence the case felt unresolved.

As Burney discusses in his first three chapters, the rise of toxicology helped produce both a new type of poisoner—exemplified by Palmer—and a new set of legal and scientific problems. Whereas before midcentury the poisoner was stereotyped as a crude criminal who fed victims easily detectable amounts of poison, the dissemination of new toxicological knowledge—in part through expert testimony presented in murder trials—meant more sophisticated and less easily detectable murders. In turn, the trials of such sophisticated poisoners required toxicological expertise to prove that poison had indeed been administered. These shifts had to be met by a perceptual shift: deep-rooted misconceptions about poison had to be replaced by other imaginative constructs. Developments in toxicology required an imaginative leap in interpreting a corpse that might show no sign of murder, and a defendant who might look the very picture of respectability.

Burney's final two chapters focus in detail on Palmer's trial and its aftermath. As he comments, “Palmer's case gripped the public imagination as no other poison trial had done before” because it “crystalliz[ed] an evolving set of discourses linking poison to the conditions of civilized society, with Palmer himself figuring as the very embodiment of the modern poisoner” (121). For Burney's purposes, the Palmer case crystallizes the institutional and scientific problems associated with criminal poisoning, most notably the use of scientific evidence in criminal trials, and the role of the expert in providing testimony, particularly in the hostile climate of the adversarial courtroom system.

Burney explains in detail the evidence given against Palmer by expert toxicologist Alfred Swaine Taylor. Taylor faced a difficulty: as an alkaloid, strychnine was far more difficult to trace in a corpse than a mineral poison such as arsenic. Although Taylor could produce much in the way of indirect evidence that Cook had been poisoned with strychnine, including Cook's tell-tale “tetanic” spasms (137), the lack of physical residue of poison extracted from the body troubled many. Faced with defense witnesses who contradicted his contention that strychnine had been administered but had left no detectable trace, Taylor—himself the foremost authority on toxicology in Britain—found himself arguing against the certainty of material evidence.

Burney is at his best in detailing the contradictions and tensions faced by experts in presenting scientific evidence. Rather than such experts being regarded as objective, the questioning of expert testimony in the Palmer trial generated the suspicion that no expert could be impartial, and no scientific evidence wholly reliable. This interplay between science and interpretation is examined further in Burney's account of a later trial, that of Thomas Smethurst in 1859. Smethurst, like Palmer a doctor, was accused of poisoning his mistress with arsenic. A supposedly reliable test had been developed to detect the presence of this mineral, and Taylor was brought in to testify that, in his analysis, one bottle from Smethurst's collection had indeed contained arsenic. Yet Taylor soon had to retract his testimony: his results had been skewed by contamination from the copper gauze crucial to the test. The arsenic he had detected had been introduced into the sample by the very test he had been using to find it.

Although convicted, Smethurst was soon pardoned. As the Home Secretary explained, the decision was necessary because of “the imperfection of medical science, and from the fallibility of judgment … even of skilful and experienced medical practitioners” (167). Such a pronouncement meant a dashing of the grand hopes for toxicology. Yet, as Burney points out, such problematic cases as Palmer's and Smethurst's forced a reconsideration of the role of expert testimony—not only in the courtroom, but also in parliamentary hearings, civil cases, and beyond—and helped determine the relationship of science and law for many years to come.