On 25 June 1855, Professor Robert Christison received a letter from the medical attendants of Mrs Wooler, who lay dying near Darlington. They suspected arsenic, yet their initial analyses had yielded only ambiguous results. Christison examined the patient’s urine: therein he detected the poison. Before his opinion could reach them, Mrs Wooler expired. The post-mortem examination subsequently revealed arsenic within the liver and other organs. The medical fact was established at the very moment the judicial inquiry began: who had administered the poison?
The matter reached back to the beginning of May. Mrs Wooler, a lady of delicate constitution aged about thirty-eight, had vomited after an ordinary repast. The earliest days were poorly documented. Her medical attendant saw her on 8 May, observing digestive disturbances, pain, loss of appetite, and an encroaching debility. Toward the close of the month, the vomiting and diarrhoea worsened; the mouth and throat grew inflamed, and swallowing became an agony. Christison’s account, published several months after the affair, was drawn from clinical notes and depositions heard at the trial. He himself pointed out the lacunae in this clinical history.
In June, the clinical picture grew darker still. Mrs Wooler suffered from thirst, abdominal pain, hiccups, and an agitation observed by the physicians at her bedside. Her pulse mounted exceedingly high. An eruption broke out upon her face and arms; she subsequently experienced numbness and tingling in her hands. The symptoms arrived in successive paroxysms, without departing from their general course. On 27 June, following muscular spasms that had become almost continuous, she passed away at half past ten in the morning. To the very end, wrote Christison, she preserved her faculties.
The family physician had at first contemplated other maladies, notably tuberculosis, of which the autopsy revealed slight pulmonary traces. Yet these were quiescent and could not account for the observed progression. The corpse exhibited extensive inflammation of the alimentary canal; the bowel was ulcerated in parts, the liver altered, the kidneys congested. Several practitioners subsequently analysed the viscera. Dr Henzell detected arsenic in the liver; Dr Taylor likewise discovered it in various tissues and in fluid drawn from the abdomen. Christison had found it in the urine collected prior to death. The physicians were agreed: arsenic had been administered repeatedly.
This certainty pointed to no single individual. Mrs Wooler resided at Burdon, near Darlington, with her husband, a retired merchant, and a small domestic establishment. She was childless. According to Christison, the couple appeared attached to one another, and no evidence suggested any cause for estrangement. He could discern neither an obvious pecuniary motive nor any trace of enmity. Yet the husband’s proximity afforded repeated opportunities: he remained at her side, assisting in the administration of food, drink, and medicine. During the final weeks, he had also assisted in administering enemata—a practice Christison deemed unusual for a husband without medical training.
The brief contained further grounds for suspicion. One of the two syringes employed for these administrations was later pronounced to bear traces of arsenic. Yet it had lain for several days in an unlocked cupboard, under the watch of a police officer. A bottle of arsenical solution, kept amongst other medicines, had vanished after the demise; no one proved that Mr Wooler had taken it. Even had it been full initially, it contained far too small a quantity to account for several weeks of poisoning. The husband possessed diverse potent drugs, among them toxic substances, though several were probably remnants from his former residences in India and at the Cape. No recent purchase of arsenic was ever established.
The depositions left other possibilities equally open. The housemaid and a fifteen-year-old niece had stayed in attendance upon Mrs Wooler; a lady from the neighbourhood had visited her. Christison considered that their opportunities were insufficient to explain the prolonged administration of the poison, yet his paper offered no day-by-day demonstration to that effect. He also observed that the physicians obtained clear chemical proof only after several attempts. On 23 June, a sample of urine differed suddenly from the preceding specimens; it might have been substituted by error or design, though the author of the act remained unknown. On the morrow, the urine resumed its ordinary characteristics.
Christison had not entered the case as an investigator. The local practitioners had solicited his opinion upon the analysis; he had agreed upon the condition that he should not be summoned as a witness, having theretofore declined distant forensic commissions. He offered, nonetheless, to appear if his presence might serve the accused or the ends of justice. The prosecution eventually subpoenaed him: he was, so he stated, the sole authority to have established the indisputable presence of arsenic in an excretion drawn from the patient during her lifetime. This position explained both his authority and his circumspection: his narrative came from an expert who had taken part in the case, not from an indifferent clerk of court.
The initial coroner’s jury returned a verdict of death by poison, without naming the perpetrator. Relatives of the deceased, dissatisfied with this conclusion, petitioned the Home Secretary for a fresh inquiry. Following an examination by the Darlington magistrates, Mr Wooler was committed to custody upon the charge of murder by poisoning. The trial opened at the Durham Assizes on 7 December and lasted three days. Christison, professor of medicine and toxicology, attended the first two days; he reconstructed the remainder from information communicated to him. His paper is the account of an expert witness, not an exhaustive transcript of the proceedings.
The prosecution could rely upon the incontrovertible presence of the poison, the husband’s continuous access to the patient, and a chain of unusual circumstances. Yet none of these indications, taken alone, crossed the threshold of direct culpability. Christison acknowledged that the suspicious circumstances appeared extraordinary when viewed collectively, yet could be explained separately without strained conjecture. He could discover no motive, and insisted upon the mutual affection displayed by the spouses. The physicians established death by arsenic; the link connecting the poison to a specific hand remained of an entirely different nature.
The defence vigorously assailed the medical men for having delayed in disclosing their suspicions. Christison devoted a substantial portion of his paper to this question. In his view, a suspicion of poison was not yet a certainty, and to accuse the husband prior to a conclusive analysis might ruin an innocent man or permit a guilty party to efface every trace. He himself had counselled awaiting firmer proof. The Darlington practitioners had sought confirmation in the urine; the results remained ambiguous until the very end. The patient expired before they could act upon a certainty.
The dispute regarding this delay assumed an importance far exceeding the trial itself. According to the report Christison consulted, the learned judge appeared to intimate that the medical attendants ought to have warned the husband upon the very first suspicion of poison, or applied to a magistrate had they suspected him. Christison regarded such advice as perilous: a medical hypothesis still in doubt might wrongfully accuse, whilst a premature warning would enable a guilty party to destroy the evidence. His own rule was otherwise. Once the physician was convinced that poison was at work, he was bound, in Christison’s judgment, to warn the patient herself; she might know the source of the peril or recognize the person administering it. He added that the medical men had hesitated to impart this terrible truth to Mrs Wooler, who was exceedingly feeble and near to death. Their prudence had thus not merely sheltered a potential suspect; it had spared the sufferer a disclosure they shrank from imposing upon her without sufficient proof.
The jury acquitted Mr Wooler. Christison approved the verdict, writing that he could point to no other person. He affirmed unreservedly that Mrs Wooler had died of arsenic; he refused to convert that certainty into an accusation against a husband whose motive and decisive proof were entirely wanting. Between the medical fact and the identity of the perpetrator, the trial left an abyss that neither the syringes, nor the missing phial, nor the husband’s proximity during the illness could bridge. The arsenic had spoken from within the corpse; it had not pronounced the name of the hand.