I have visited Oxford Castle many times, and I’m always drawn to the sad story of Mary Blandy who was executed there in 1752 for poisoning her father with arsenic under the influence of her lover. As the crime took place in Henley-on-Thames, which is close to where I used to live, it has always rather intrigued me. It’s a particularly interesting case as it demonstrates some eighteenth-century toxicology.
An only child, Mary Blandy was born in Henley around 1720. Her father, Francis Blandy, was a successful lawyer and the town clerk. He was described in the press as ‘a gentleman of the strictest honour, a most tender husband, an indulgent father, and a sincere friend’ . The family lived at 29 Hart Street in the town centre, where Mary’s mother, also named Mary, died in 1749. Mary junior was ‘a young woman of an unblemished character’ (Derby Mercury, 6 December 1751). That was until she fell in love with a captain in the army, which ultimately led to her tragic fate.
A dangerous liaison
Twenty years her senior, William Henry Cranstoun was the son of a Scottish nobleman. He met Mary while his regiment was in the area, and they fell in love. However, there was one major obstacle to their relationship – William already had a wife and child back in Scotland. Despite Mary’s father’s disapproval of the match, Captain Cranstoun returned to Scotland several times to try to have his marriage dissolved. Whilst he was away, he sent letters and packages to Mary, who had been forbidden to see him.
In August 1751, Francis Blandy fell ill, complaining of bowel pain, a sore throat, and ‘a stench in his nose’. Apparently, he confided to his doctor that he thought he was being poisoned by his daughter, to whom he referred as ‘a poor love-sick maid’. He died on 14 August. It later transpired that, earlier in the month, two maids had seen some white powder in the residue of Francis’ porridge, which had also caused them to suffer from mild symptoms when they had shared the same meal. They had told a neighbour, who had informed the local chemist, who had examined the porridge but could find nothing suspicious. As Francis’ health deteriorated, the suspicions of the household staff grew, especially as Captain Cranstoun had sent Mary some ‘Scottish powder’ for cleaning some pebbles that he had given her to be set into earrings, which she may have mixed in with her father’s food.
Incriminating evidence
After Francis’ death, the doctor warned Mary that she might be inculpated and so she burned Captain Cranstoun’s letters and the incriminating powder. However, the cook rescued the package from the flames, after which Mary tried to escape by offering the servants money. They refused to help her. Despite this, she managed to slip out one night, wearing a black cloak and bonnet. She walked unnoticed as far as the churchyard, where she was spotted by some children. Soon a crowd started following her as she reached the bridge over the Thames, and she was forced to take refuge in The Angel pub (there have been reported sightings of her ghost there!). The town’s serjeant soon heard of Mary’s attempted flight, and she was placed back under house arrest to await the official warrant from Oxford Castle.
Mary Blandy was tried at the Oxford Assizes for her father’s murder on 3 March 1752. Witness for the prosecution, Dr Anthony Addington, a fellow of the College of Physicians and a local resident, described Francis Blandy’s poor physical state, as recorded in the Manchester Mercury:
The symptoms were prickings in his fundament and bowels, his mouth and nostrils were full of pimples, and his teeth rotted out of his head.
Dr Addington told the court that Francis had suffered from bouts of diarrhoea and vomiting, which he had believed to be signs of poisoning. When he had tested the porridge given to the apothecary, he found it to be ‘white arsenic’, thus confirming his suspicions. As there was no definitive test for arsenic until 1836, Addington and a colleague submitted the powder from the gruel pan to several tests, and initial results were based on its white colour and its insolubility in water. Also, when heated it emitted strong white fumes which smelled of garlic. They then prepared a sample of arsenic and compared the chemical reaction of the poison, to that of the ‘unknown’ powder with five precipitate tests. Dr Addington concluded: ‘I never saw any two things in nature more alike than the decoction made with the powder found in Mr Blandy’s gruel and that with white arsenic.’ For the period, this was deemed to be irrefutable evidence of poisoning.
After her arrest, Mary admitted to having put the powder in her father’s food, but she claimed that she had not intended to kill him, and that she had thought it was a potion to make him more open to her relationship with Captain Cranstoun. However, her fate was sealed when a letter she had sent, after her father’s death, to William urging him to burn their correspondence was intercepted and used as further evidence against her. Mary was convicted of Francis’ murder and sentenced to death. Despite the verdict, contemporary press reports believed that William Cranstoun was ‘the first instigator and contriver of this detestable murder’, his motive being Mary’s £10,000 inheritance (about £1.4 million in today’s value), which would have passed legally to him on their marriage.
A tragic fate
On 6 April 1752, which happened to be Easter Monday, Mary Blandy mounted the scaffold in the vicinity of Oxford Castle. Dressed in black and in a ‘serene and composed’ manner, she climbed the first five steps of the ladder and then stopped, saying, ‘Gentlemen, I beg that you will not hang me high, for the sake of decency.’ Placing a handkerchief over her face, she was hanged by the neck. In spite of her request for decency, one of the sheriff’s men carried her body over his shoulder, her legs on display to all those who had gathered to see her execution. Mary’s body was placed in a coffin lined with white satin and buried alongside her parents in the churchyard of Henley parish church. There is no longer any trace of her grave, but her sorry tale is retold in the permanent exhibition at Oxford Castle. The likely instigator of Mary’s crime, William Cranstoun, fled the country to France, where he died later that year.
Mary Blandy’s trial is significant in the history of crime, because it was the first time that credible scientific proof was recorded as having been given in a poisoning case.
This is super interesting ---- and indeed really quite important. I am curious about how she was carried, was this common practice, did other women who were executed made similar pleas and were these also rejected? I love these case studies -- and it often makes me wonder if they are trends or exceptions. This case is clearly extarordinary given the role that scietnific evidence played .
There also seem to be some interesting assumptions --- a request to burn correspondence, need not imply conspiring to commit murder. Instead the letters could be lewd and perhaps they worried such spicy content would sow doubt re their character. From your article, my sense is that they did conspire... but I like to think why else would they have made such change --- what else could explain what they did.