Idiom Du Jour

Today's selection: "mad as a hatter"

Conjures up images of Alice and Wonderland, no?  But this one doesn't actually stem from the opium-laced mind of Lewis Carrol (although that may well be what's kept it alive).  Everyone knows this phrase refers to an extremely crazy person - certifiably insane, even - and this is how that came about.

It comes, not surprisingly, from the world of millinery.  Not straw boaters or lace caps though...we're talking felted beaver hats.  For a fascinating detailed history of this process (no, really!), click here - but essentially it all boils down to glue.  In order to get the individual beaver hairs to stick together and form a felt, they had to be treated with a mercury solution, which is all well and good until the hats are later steamed and molded...this process releases mercury fumes that, over prolonged exposure, attack the nervous system with very nasty results.

Interesting - as a culture, we've already lost the association between insanity and felted hat-making...I wonder how this idiom will hold up (in America at least) when the word "mad" stops referring to crazy and only means angry?