Edition: U.S. / Global

The Hatter's Shakes

Published: February 23, 1994

To the Editor:

Re "What It Was That Made Hatters Mad" (letter, Feb. 9):

Danbury, Conn., where I have lived all my life, was known as the hat city of the world. I worked as a hatter during school breaks. My grandfather was a hatter, and members of my family worked in the factories.

While mercury poisoning was a horrid industrial disease, I don't recall anyone ever taking umbrage at the term "mad hatter." Rather than insanity, its more common symptom was a generalized tremor known as the hatter's shakes. This was frequently confused with an alcoholic tremor, as Danbury was notorious for its concentration of saloons.

Mercury was used in a process called carroting, which caused the barbs on rabbit fur to erect, allowing it to knit together to make felt for hats. Because of manufacturers' research and pressure from hatters' unions, a substitute using hydrogen peroxide and acids was developed by a Swiss chemist. Mercury was no longer used after the 1930's. I doubt that any "mad hatters" are still alive. EDWIN G. FERNAND, M.D. Danbury, Conn., Feb. 14, 1994