The Robert Bonomi entity posted thusly:

In article ,
Oleg Lego wrote:
Minor trivia:
Folks who made hats used to use 'carbon-tet', and it affected their
brains. Hence the phrase "Mad as a hatter".

Sorry, but that's not quite correct.

The other 'common' use for carbon-tet was as a dry-cleaning fluid.

Hat-making used mercury in the making of the 'felt' from which many
types of hats are formed. (ranging from Stetsons, to Derbys.

Hatmakers _chewed_ (literally, as in 'masticated') the source
material, to soften it, prior to forming into final shapes.

The long-term effects of ingestion of low levels of mercury in
that work, did give rise to various forms of insanity.


The long-term effects of ingestion of low levels of mercury in
that work, did give rise to various forms of insanity.

I stand corrected. Serves me right for taking the word of someone who
told me that many years ago, without checking on it myself.