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Stranger Than Fiction

March 2022

A Taste for Poison: The Curious Case of Dr. Lamson
By Dean Jobb

A sketch of Lamson and a courtroom scene during his Old Bailey trial appeared in The Graphic in March 1882.

It was late, almost seven o’clock, on that December evening in 1881 when a visitor turned up at the boarding school in Wimbledon. George Henry Lamson asked to see his brother-in-law, Percy Malcom John. The disabled eighteen-year-old—a curved spine left him unable to walk—lived and studied at Blenheim House School.

Lamson was chatting with the proprietor, William Bedbrook, when John’s chair was wheeled in. He had brought a Dundee cake—a Scottish version of a fruitcake—to celebrate John’s upcoming birthday. All three ate a slice. Then Lamson, an American-born doctor with a practice in the English Channel resort town of Bournemouth, made a strange request.

He produced a box of empty gelatin capsules he had purchased on a recent visit to the United States. When filled, they made bitter-tasting medicines easier to swallow. They were still a novelty in Britain.

“You will find them very useful to give the boys medicine,” Lamson told Bedbrook. The doctor filled one with sugar and asked his brother-in-law to demonstrate.

“Percy, you are a champion pill-taker; take this,” he said. “Show Mr. Bedbrook how easy it is to take.” The youth obliged, and swallowed the capsule.

Within minutes, Lamson announced he had to leave. He was on his way to Paris and had to catch the next train for Dover, or he would miss the ferry. He had been gone no more than ten minutes when John complained of heartburn. The youth was soon seized with convulsions so severe that schoolmates had to hold him down on his bed. Doctors were summoned but could do nothing to save him. After writhing in agony for four hours, he died. It was “as painful a passing,” the British crime writer Hargrave Adam later noted, “as ever was visited upon a suffering mortal.”

The doctors suspected he had been poisoned and preserved a sample of his vomit for examination. The lethal dose must have been in the capsule Lamson had provided. But what kind of poison had killed Percy John? And what had possessed Lamson to brazenly administer the poison in front of a witness? In an era when laboratory tests were primitive and judges and juries were only beginning to trust the opinions of expert witnesses, it would be up to Britain’s top forensic scientist to find the evidence needed to convict the teenager’s killer.

“No poisoner can escape him,” a journalist said of British toxicologist Dr. Thomas Stevenson. (Author Collection)

Lamson returned to London after five days in Paris. He had been identified as a suspect in the press and visited Scotland Yard. “I have called to see what is to be done about it,” he told the lead investigator, the ominously named Inspector Butcher. Lamson apparently thought he would be questioned as a witness and released. Instead, he was arrested and charged with murder.

He seemed an unlikely suspect. The son of a clergyman whose family tree included one of America’s Founding Fathers, Alexander Hamilton, he was just twenty-nine and had risked his life to save others. He had served in the French ambulance corps during the Franco-Prussian war and, later in the 1870s, was decorated for his service as a military surgeon in Serbia and Romania. He was, one friend asserted, a kind and generous man and a genial companion.

A motive, however, soon emerged. Lamson, detectives discovered, had become addicted to morphine and was facing financial ruin. He had borrowed from friends, pawned his watch and surgical instruments, and cashed checks on overdrawn or bogus bank accounts. But he still needed more money.

Percy John, as it turned out, was due to receive a sizeable inheritance—£1,500, or more than $200,000 today—when he turned nineteen. If he died before his birthday in mid-December, however, the money would pass to Lamson and his wife. The youth’s sudden death, just days before he became entitled to the money, offered a windfall to a man drowning in debt. And there was more damning evidence. As he lay dying, John told his doctors he had endured similar symptoms in the past, after taking medicine Lamson had provided.

The next challenge was identifying the poison. By the 1880s the poisoner’s old standby, arsenic, was “out of fashion,” as one British politician put it. A reliable chemical test had been developed to detect it. But would-be murderers had no shortage of alternatives—scientists were identifying new plant toxins, including strychnine from a tree found in India, nicotine from tobacco leaves, and aconitine, derived from the monkshood plant.

A Belgian chemist, Jean Servais Stas, devised a process for extracting these alkaloids from human tissue as early as the 1850s. But which poison was it? While laboratory tests were developed to detect a few of the culprits, most toxicologists relied on primitive, almost ghoulish methods. Some extracted liquids from corpses, distilled it, and touched a small amount to their tongues, to see if they experienced the same burning or tingling sensation as they had when they sampled alkaloids. Extracts were also injected into frogs, mice, and other small animals to see if their death throes mimicked the symptoms associated with a particular poison.

Poisoning allegations brought a new player into the nineteenth-century courtroom: the expert witness. Prosecutors recruited doctors and chemists to prove that a victim had been poisoned, to identify the toxin used, and explain complex laboratory tests. Defense lawyers rounded up medical men and scientists who disputed these findings and chalked up deaths to natural causes. But jurors who had the power to send murderers to the gallows wanted certainty, not conflicting opinions. If experts could not agree on the cause of death, who should they believe?

Public confidence in forensic science was shaken in 1859, after a London doctor, Thomas Smethurst, was accused of murdering his pregnant mistress. Britain’s most esteemed toxicologist, Alfred Swaine Taylor, detected arsenic in a bottle of medicine found in Smethurst’s possession.


But by the time the case came to trial, Taylor realized he had made a mistake and testified that the arsenic had come from materials used in his tests. A jury convicted Smethurst anyway, but the evidence was so muddled—other doctors believed the woman had died of dysentery—that the British government stepped in and issued a pardon. “In the eyes of the general public—from whom all juries were drawn,” observed the writer Colin Evans, an authority on the history of crime detection, “forensic science was now a seriously flawed product.”

Justice Henry Hawkins, the judge at Lamson’s trial, believed the aconitine was added to a slice of cake served to the victim. (Author Collection)

Taylor’s successor faced the challenge of restoring faith in science as a crime-fighting tool. Thomas Stevenson, a medical doctor and chemist, was recruited in 1872 to test autopsied samples when poisoning was suspected. By the time of Percy John’s murder he was the British government’s senior analyst in poison cases, with a reputation for thoroughness and precision. “To the guilty he was a veritable voice of doom,” noted one journalist. “No poisoner can escape him,” claimed another. After years of methodical taste tests, he claimed to be able to identify at least fifty alkaloid poisons by touching samples to his tongue.

Stevenson’s experiments in the Lamson case were not for the squeamish. He used the Stas process to liquify samples of the victim’s internal organs, stomach contents, and vomit. A London druggist had come forward to report that Lamson had purchased aconitine, a deadly toxin derived from the monkshood plant, barely a week before the murder. There was no chemical test to detect aconitine—and none has ever been developed, reports science writer and poisons expert Kathryn Harkup—so Stevenson tasted the revolting liquids. He felt a “biting and numbing effect” on his tongue, “as if a hot iron had been passed over it.” Then he tasted aconitine, which produced an identical burning, numbing sensation that persisted for hours. Next, he injected a sample of the victim’s urine under the skin of a mouse; it died within a half-hour. When aconitine was injected into other mice, the animals exhibited similar symptoms as they died.

When the Wimbledon Poisoning Case, as it became known in the press, went to trial in London’s Old Bailey in February 1882, the lawyer defending Lamson tried to discredit Stevenson’s findings. European scientists had recently discovered alkaloids in cadavers, produced naturally during decomposition. Could this be the source of the mouth-burning substance recovered from John’s remains? Stevenson deflected the attack. While he knew little about the new research, he said, he trusted his tongue. He was certain he had tasted aconitine.

Stevenson’s commanding presence on the witness stand—he was “clearly a master of his profession, calm and meticulous,” notes Victorian-era crime specialist Linda Stratmann—won the day. The jury deliberated just half an hour before declaring him guilty. Lamson confessed shortly before his execution in April 1882, blaming drug abuse for clouding his judgment and driving him to commit murder. Stevenson and his methods were vindicated.

One question remained unanswered. How had Lamson administered the poison? The school’s proprietor, Bedbrook, was certain he had not seen Lamson put anything other than sugar—sugar from the school’s kitchen—into the capsule John swallowed.


And Lamson’s demonstration smacked of a diversion staged for Bedbrook’s benefit, so there would be an independent witness to confirm there was no poison in the capsule.

That left the Dundee cake. The judge who presided over the trial, Justice Henry Hawkins, was convinced that Lamson had added aconitine to a section of the cake, then served the poisoned slice to John while he and Bedbrook ate untainted portions. Hargrave Adam reached the same conclusion when he chronicled the case for the Notable British Trials series in 1913.

But Stratmann, who offers the most recent account of the Lamson case in her 2016 book The Secret Poisoner: A Century of Murder, rejects this theory. The burning sensation Stevenson described would have been far worse for Percy John, who would have spat out the cake or stopped eating it. She suspects the poison was already in the capsule Lamson topped up with sugar or, in “a piece of misdirection worthy of a conjuror,” he had switched that capsule with one containing poison when Bedbrook was distracted.

Regardless of how the poisoning was accomplished, Stevenson’s testimony and findings helped to build confidence in forensic science and expert testimony. Lamson, Hargrave Adam asserted, was a “cunning and subtle poisoner” and responsible for “one of the most cruel, callous, and calculating crimes that the mind of man can conceive.” But he proved to be no match for a skilled and determined scientist with a taste for poison.

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