"Mad as a Hatter"

While vacationing this past summer I came across an interesting book called Endangered Phrases, Intriguing Idioms Dangerously Close to Extinction by Steven D. Price.  It came in handy this past Halloween when my granddaughter appeared as the Mad Hatter.

If you've read Alice in Wonderland you know that Lewis Carroll named his character the Hatter, not the Mad Hatter. The new name took hold not only because of the character's eccentric behavior but for the fact that during the time the book was written hatters often went mad due to mercury poisoning.  In the 1800s when hat manufacturers used a mercury solution to turn fur into felt, the hatters breathed in the highly toxic vapors. An accumulation of mercury often led to trembling or "hatters' shakes."

 Interesting, isn't it, how a child's Halloween costume can lead to new information?