Kate Griffin , author of the Kitty Peck novels set in the criminal underworld of Victorian London, examines the nineteenth century origins of toxicology

Poison is a deliciously evil word. Say it now – purse your lips and savour the shape, if not the taste, of those sleek, fat vowels filling your mouth. Quite thrilling, isn’t it?



The Victorians couldn’t get enough of it, metaphorically speaking. Nothing appealed more to an increasingly literate public than lurid newspaper reports of murder trials involving poison, especially if the suspect was female. And if the suspect was female and attractive sales would rocket.

Take the case of 22-year-old Madeline Smith. In 1857, this beautiful and well-connected Glasgow socialite was accused of murdering a humble clerk called Pierre Emile L’Angelier. Her weapon of choice was a mug of cocoa laced with arsenic.

The nation was gripped, scandalised and titillated by reports of her trial, which included windowsill trysts, pre-marital sex and a cache of passionate letters.

It was a standard story of a poor boy aiming his sights too high. When Madeline became engaged to a friend of her wealthy father, L’Angelier threatened to reveal their correspondence. A short time later he was dead and the trail of evidence led back to the steamy letters and the steaming mug in Madeline’s hands.

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Poor L’Angelier’s symptoms as reported by his landlady – stomach pain, sweating, spasms and sickness – were common in an age when cholera was rife, but they were also suspicious enough to warrant a postmortem. Unfortunately for Madeline, the toxicology report presented at his trial included the exact number of arsenic grains detected in his stomach amid the remains of his last night-time beverage.

Fortunately, however, she was wealthy enough to be defended by a brilliant advocate, John Inglis. His assertion that there was simply not enough evidence to convict his client (combined with the fact that the public was charmed by the suspect’s pretty face and apparently sweet nature) meant that the jury eventually returned a (Scottish) verdict of “not proven”.

Madeline went free. Four years later she married Pre-Raphaelite artist George Wardle, a business partner of William Morris, which perhaps hints at her bohemian nature and beauty.

It’s easy to see that even today, the case of Madeline Smith would have been a tabloid page-turner, but beneath the glitter of sex, society and deadly cocoa, there’s an interesting scientific point. More than 150 years ago, a detailed toxicology report confirming the presence of arsenic in L’Angelier’s stomach was submitted as evidence in a court of law.

Although poison was viewed as a particularly cool and calculatingly feminine murder weapon, it was not only women who chose to administer it. Contrary to those floridly sensational reports in the cramped columns of Victorian newspapers, plenty of men chose poison as their method of dispatch. It was a crime of ‘fashion’.

Arsenic, known since Roman times as the “King of Poisons”, was easily available to both sexes. Once payment was made, all that was needed to complete the transaction was the buyer’s signature in the ‘Poison Book’ kept in every chemist and hardware shop. People purchased arsenic in quantity as rat poison, and chemists didn’t ask questions when women bought it for cosmetic use to improve their complexion.

The sexual frisson of the Madeline Smith case was perhaps an anomaly. A great number of Victorian poisoning cases revolved around the far less stimulating theme of life insurance; in fact, the development of the life insurance industry in the first half of the 19th century corresponded to a rise in poisoning cases. Effectively, anyone with a policy had a price on their head that an unscrupulous relative could claim if they were prepared to commit murder. In France, arsenic actually became known as poudre de succession – “inheritance powder”.

It was easy to obtain, easy to administer, but difficult to prove. And for that reason the science of toxicology became increasingly important – especially to insurers. Although tests for the presence of arsenic had been developed since the late 18th century, until 1836 they were unreliable.

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It’s likely that we know that L’Angelier’s stomach contained 70 grains of arsenic because it had been subjected to the Marsh test.

In London in 1832, one John Bodle was accused of murdering his grandfather by putting arsenic in his coffee. During the trial, the prosecution called on James Marsh, a Scottish chemist working at the Royal Arsenal, to try to detect the presence of poison in the contents of the old man’s stomach. He performed the then standard test of passing hydrogen sulphide through the suspect fluid, which produced a distinctive yellow precipitate indicating arsenic.

The problem was that the precipitate did not keep well. By the time it was presented to the court the sample had deteriorated. The jury was not convinced and Bodle was acquitted.

When Bodle later confessed that he had killed his grandfather after all, Marsh – who had always believed him to be guilty – was infuriated and determined to ensure that in future justice would be done. Basing his work on previous ideas, in 1836 he developed a glass apparatus capable not only of the detection of minute traces of arsenic, but also of measuring its quantity.

And here we come to the case of another beautiful woman.

The first publicly documented use of the Marsh test, indeed, the first time forensic toxicology was ever introduced as evidence in a court case, occurred in Tulle, France, in 1840 with the infamous affair of Madame Marie LaFarge.

Like Madeline Smith, Marie, a descendant of King Louis XIII, was well-connected. Her arranged marriage to Charles Pouch LaFarge, a robustly coarse man, was a matter of expedience – Charles needed money to repair his ramshackle estate, and, at 23, Marie needed a husband. The union was not a success.

The house into which Charles installed his aristocratic bride days after their wedding in August 1839 was damp and rat-infested. In fine gothic tradition it stood within the ruins of a former monastery. To make matters worse, Marie was appalled by her peasant in-laws, who, in turn, distrusted her.

Less than five months later Charles was dead and Marie was suspected of having poisoned him. The evidence centred on a Christmas cake, nuggets of venison, truffles and a small, mysterious malachite box, the powdery contents of which Marie had been seen to stir into her husband’s festive eggnog.

With Charles not quite cold on his death bed the entire LaFarge family cried foul and pretty, grieving Marie became a Europe-wide celebrity.

When she entered the assize court of Tulle for the first time on September 3, 1840, dressed in mourning and carrying a small bottle of smelling salts in her trembling hand, spectators were immediately divided into pro- and anti-Marie factions. Like the case of Madeline Smith 17 years later, the LaFarge affair became the stuff of newspaper gold.

The circumstantial evidence stacked against Marie was great. In November 1839, she had bought arsenic from a local chemist, saying it was to kill the rats infesting their home. She had sent cake to her husband while he was attending to business matters in Paris, and, moreover, their maid swore that she had often seen her mistress mix a white powder into his drink.

Tests were carried out on the remains of the food and drink that Charles’s suspicious relatives had retained. The food was found to be positive for arsenic using the old methods as well as the new Marsh test (the eggnog alone contained enough “to poison ten persons”), but when LaFarge’s body was exhumed the local chemists assigned to the case were not able to detect poison.

It was at this point that respected chemist Mathieu Orfila, an acknowledged authority on the Marsh test, was called (ironically by the defence) to examine the results. He performed the test again and demonstrated that it had been carried out incorrectly. This time round, Orfila was able to prove conclusively the presence of arsenic in LaFarge’s exhumed body.

Amid uproar in court, Marie was found guilty and sentenced to life imprisonment with hard labour at Montpellier gaol, although the latter part of the sentence was subsequently commuted. Twelve years later in June 1852, suffering from tuberculosis, she was released. She died in November that same year, protesting her innocence to the last.

It was a controversial case to Marie’s bitter end. One of the first trials to be followed by the public through daily newspaper reports, it divided the country and became an international cause celebre. It was also notable for the fact that Marie LaFarge was the first person convicted, largely, on direct forensic toxicological evidence. Indeed, the notoriety and ‘success’ of the LeFarge conviction meant that Orfila went on to be recognised as the founder of the science of toxicology.

Extensive coverage in the French press gave the field of forensic toxicology the publicity and legitimacy it deserved and the Marsh test was hailed as a wonder of modern science. In fact, the test itself attracted so much interest that for a while it became something of a fairground attraction. Demonstrations were conducted in salons, public lectures and even in popular melodramas recreating the LaFarge case.

More importantly, the existence of a proven, reliable test served as a deterrent. Murder by arsenic became rarer because, at last, it left a detectable trace at the crime scene. The King was dead.

It is an interesting echo that some 20 years later Charles Dickens chose to give the name ‘Madame DeFarge’ to his murderous tricoteuse in A Tale of Two Cities.

Kitty Peck and the Music Hall Murders and its sequel, Kitty Peck and the Child of Ill-Fortune are published by Faber and Faber