|The Hatter character in Alice's Adventures in Wonderland (1865)|
In the late 14th and 15 centuries hats started to be worn regularly. During that period hats for men were considered an important fashion item, unlike women’s hats which only became considered as a fashion item in the 18th Century.
Millinery has existed in Britain since the 1700's. In English courts the term milliner was used and this was derived from the term for travelling haberdashers from the Duchy of Milan in Italy. These travelling sales people sold 'Millayne bonnets' and all the items necessary to dress, and were called millainers.
Today technically a hatmaker makes hats for men whilst a milliner makes hats for women.
Running parallel to these hat making arts were feather workshops called plumassiers where feathers were dyed and made into arrangements from boas to aigrettes to tufts and sprays for both the worlds of fashion and interiors.
Mercury salts, which we now know to be highly toxic, were used in the process of curing pelts used in felt hats. It was impossible for hatters to avoid inhaling the mercury fumes, so they often suffered mercury poisoning, causing neurological damage, including confused speech and distorted vision. Hatters commonly suffered from 'hatter's shakes', a form of nerve damage which gave symptoms similar to Parkinson's Disease and which is still known today as 'Mad Hatter's Syndrome'.
Mercury exposure can cause aggressiveness, mood swings, and anti-social behaviour including excessive timidity, diffidence, increasing shyness, loss of self-confidence, anxiety, and a desire to remain unobserved and unobtrusive. It was not unusual for hatters to appear disturbed or confused, and many died early as a result of mercury poisoning.
Whilst the phrase 'as mad as a hatter' predates Lewis Carroll's books, his 'Hatter' character from Alice's Adventures in Wonderland (1865), is of course the best-known mad hatter of them all.