How The “Yorkshire Witch” Scammed 1806 Leeds With Apocalyptic Chicken Eggs And Simple Chemistry


Francesca Benson

Junior Copy Editor and Staff Writer

clockApr 13 2021, 12:16 UTC
angel egg

Mary Bateman claimed that one of her hens had laid three eggs magically inscribed with a message: “Crist is coming” (spellcheck didn’t exist in 1806). Image Credit: Porubski Photodesign/

History is full of people claiming to possess magical powers who then get exposed as liars. However, some cases are more bizarre than others. The story of the Yorkshire Witch is one of these, a story involving deceit, murder, and prophetic eggs. And no, this isn’t the kind of egg fiasco that landed Goop with a hefty fine for telling tales. This tale dates back to the 1800s, in the city of Leeds in West Yorkshire, England.

Mary Bateman – maiden name Mary Harker – was born in the village of Asenby, North Yorkshire, in 1768. Her father was a farmer, and Mary apparently received a good quality education for someone of her class, being able to read and write proficiently.


However, after living in York for a year, Mary had to flee to Leeds after being caught red-handed committing robbery. According to a biography of Bateman, she “displayed what may have been a pathological need to steal. She was, moreover, none too discreet in the manner of her robberies.” She was caught in the act multiple times, perhaps bribing her victims to avoid facing the legal consequences of her actions.

Alongside her propensity for stealing, Mary Bateman also had a more spiritual side hustle as a wise woman, telling fortunes and supposedly removing harmful spells placed upon her clients.

Like many people at the time, Bateman kept chickens to keep her supplied with fresh eggs. However, in 1806, she claimed that one of her hens was laying eggs magically inscribed with a message: “Crist is coming”. Presumably the message was meant to say “Christ is coming”, but spellcheck didn’t exist in 1806, and who has time to proofread when the Messiah is due to return any minute?


This revelation had exactly the reaction Bateman wanted. Huge numbers of people lined up, each paying a penny to view the mystical eggs and the magical chicken laying them. Those who witnessed this were whipped into a frenzy, convinced that the apocalypse was upon them. Mary also began selling “seals” assuring admission into heaven after the chicken-foretold apocalypse – these “seals” were just pieces of paper with the letters “JC” on them.

However, not everyone believed the story of the magical apocalypse eggs. Some skeptics got up early in the morning, hiding out near Mary Bateman’s house to observe her. A passage in the book Extraordinary Popular Delusions and the Madness of Crowds explains what they found:

“Some gentlemen, hearing of the matter, went one fine morning, and caught the poor hen in the act of laying one of her miraculous eggs. They soon ascertained beyond doubt that the egg had been inscribed with some corrosive ink, and cruelly forced up again into the bird’s body. At this explanation, those who had prayed, now laughed, and the world wagged as merrily as of yore.”


It turned out that this “corrosive ink” was concentrated vinegar. Vinegar is a solution of acetic acid, usually containing between 4 to 8 percent acetic acid. Eggshells are mostly made of calcium carbonate – also a common ingredient in antacids. Limestone is also mostly made up of calcium carbonate, and is known to be dissolved by acid rain.

Therefore, when the vinegar was painted onto the eggs, the acetic acid reacted with the calcium carbonate in a chemical reaction that ends up producing carbon dioxide, water, and calcium acetate, dissolving the shell and forming the ominous message while not damaging the inner membranes of the egg. Mary Bateman reapplied the vinegar multiple times to ensure the message was “sufficiently burned in” before ramming them back up the poor bird’s cloaca, so it seemed that the inscription happened while the egg was still in the chicken.

After her scam was exposed, Bateman sold the bird – which went on to be named the “prophet hen of Leeds” – to a neighbor, and it stopped laying the inscribed eggs.


Unfortunately, this wasn’t the end of Mary Bateman’s scamming career. A woman named Rebecca Perigo consulted Mary about a pain in her breast, which Bateman said was the result of an “evil wish”. As part of her magical – and pricey – cure, Bateman fed both Rebecca and her husband William poisoned pudding. Rebecca ended up dying, and Mary Bateman was hung at noon on March 20, 1809, for murder and fraud.

Bateman’s body ended up being put on display at Leeds General Infirmary, with people paying to see her and even buying cured cuts of her skin to use as charms. Her body was also put on display at the Thackray Medical Museum in Leeds until 2015. Mary Bateman, dubbed the "Yorkshire Witch" after her magical escapades, certainly never chickened out of making a quick buck.