“Mad as a hatter” is a colloquial phrase used to refer to a crazy person. In 18th & 19th century England mercury was used in the making of felt, which was used in the manufacturing of hats. People who worked in these hat factories were exposed
“Mad as a hatter” is a colloquial phrase used to refer to a crazy person. In 18th & 19th century England mercury was used in the making of felt, which was used in the manufacturing of hats. People who worked in these hat factories were exposed
