Mad as a Hatter
"Mad as a hatter" is a colloquial phrase referring to a crazy person — many of whom are found in fashion. The phrase stems from 18th and 19th century England, when mercury was used in the production of felt, which was essential to the manufacture of hats at the time. The workers in the factories were daily exposed to traces of the metal. As this accumulated over time, many of them developed dementia from the poisoning — and it became known as mad hatter’s syndrome. The phrase, which refers to someone seen as insane, was immortalised by the character of the Mad Hatter in Lewis Carroll’s Alice in Wonderland.