My god

Just found out from 1000 ways to die:

For some unknown reason those who mad hats in the 17-1800s would eventually go crazy after a few years in the hat business.

The condition eventually became known as the Danbury Shakes.

The Danbury Shakes were named after Danbury Connecticut which was considered hat central.

They used mercury at an ingredient in one of the mixtures that furs/pelts were boiled when prepping them for use during a process called "carroting". As a result the fumes would become inhaled.

After a time the fumes from the boiling mercury would cause the businessmen to become crazy, or mad.

Mercury poisoning attacks the nervous system, causing drooling, hair loss, uncontrollable muscle twitching, a lurching gait, and difficulties in talking and thinking clearly. Stumbling about in a confused state with slurred speech and trembling hands, affected hatters were sometimes mistaken for drunks. In very severe cases, they experienced hallucinations.

They were called Hatters, and then became mad hatters. MFW i realized the connection. o.0

The Mad Hatter in Alice in Wonderland wasn't just crazy. He was slowly dying from mercury poisoning, and nobody knew.