Hatter

A hatter is a maker or seller of hats. The proverbial expression "mad as a hatter" may refer to the mercury-poisoning suffered by many hatters in the eighteenth and nineteenth centuries, when mercury was used in the manufacture of felt.

See also:

The Hatter in Alice's Adventures in Wonderland

External Links

• "Mad as a Hatter" at Urban Legends (http://www.snopes.com/language/phrases/hatter.htm)
• Questions & Answers: Mad as a Hatter (http://www.quinion.com/words/qa/qa-mad2.htm)