Erethism, more commonly known as mad hatter disease, 🎩 is caused by mercury poisoning and can cause a variety of symptoms including tremors, timidness, anxiety, and even hallucinations. 🧚♀️It was quite common among hat-makers as they were exposed to mercury used in the manufacturing of felt hats.
Even though the Hatter from Alice’s Adventures in Wonderland 🐛doesn’t display all of these symptoms, his creation might have been inspired by erethism. We know that Lewis Carroll’s uncle, Robert Wilfred Skeffington Lutwidge, was a Lunacy Commissioner supervising Pauper Lunatic Asylums. To keep patients busy, these asylums often organized group activities such as … tea parties. 🧐☕️
On a related note, check out this video about the “mad as a hatter” expression 🙂