Fact Check

Etymology of Mad As a Hatter

Does the phrase 'mad as a hatter' refer to hat-makers poisoned by mercury fumes?

Published April 24, 2000


Claim:   Working each day with mercury-soaked felt turned hat makers crazy, hence the phrase 'mad as a hatter.'

Status:   Undetermined.

Origins:   In the 18th century, mercury salts were used to make felt for fancy hats. The process required copious amounts of the element, a substance then not understood to be as dangerous as we now know it to be.

Hat makers who day after day handled mercury-soaked fabric risked mercury poisoning, a condition that affects the nervous systems. Those so exposed would in time develop uncontrollable twitches and trembles, making them appear demented to the casual observer.

Even though there exists a strong tie between mercury poisoning and strange behavior in those long-ago hatters, it's still more than likely the term we now toss about so casually did

not spring from this combination. Phrases such as mad as a March hare, mad as a buck, mad as Maybutter, and mad as a wet hen are older than mad as a hatter, leaving open the conclusion that hatter is but a variation of an existing term. (Interestingly, these other phrases pull in different directions, with mad as a March hare signifying odd or eccentric behavior, while mad as a wet hen characterizing anger.)

Whatever the definitive origin of mad as a hatter, we know the term wasn't coined by Lewis Carroll in his 1865 Alice's Adventures in Wonderland. The saying turns up in Thackeray's 1849 Pendennis and Thomas Chandler Haliburton's 1837 The Clockmaker.

Carroll's "hatter" might well have been modeled on Theophilus Carter, an eccentric furniture dealer who characteristically sported a top hat. Carter was neither a hat maker nor had been exposed through his work to mercury fumes — if he had indeed been Carroll's inspiration for the "Mad Hatter" of Alice, it would have been because he was a somewhat nutty real-life character much given to the wearing of highly noticeable hats. There also exists a possibility Carroll was unaware of the mercury connection to the existing saying. It's also possible he had not previously encountered the saying and thus thought he had coined it himself.

Carroll's Alice is replete with word play. He loved to twist words, and encoding double and triple meanings into his work was for him part of the fun. His Mad Hatter could therefore be a caricature of Theophilus Carter, a real person of his acquaintance, while his mad as a hatter could have been a twist on the pre-existing saying, mad as a March hare. Those familiar with Alice will recall that the March Hare was the constant companion of the Mad Hatter.

Moreover, mad at that time had more than a few meanings: "off the rocker" and "angry," but also "venomous," which suggests yet another twist in the game. According to A Dictionary of Common Fallacies:

Lewis Carroll with his penchant for linguistic games presumably knew perfectly well that his "Mad Hatter' meant 'a venomous adder', but since his readers may have been misled by Tenniel's drawings, it should be pointed out that 'mad' meant 'venomous' and 'hatter' is a corruption of 'adder', or viper, so that the phrase 'mad as an atter' originally meant 'as venomous as a viper'.

Supporting the "adder" theory comes this entry from an 1882 phrase origin book:

In the Anglo-Saxon the word 'mad' was used as a synonym for violent, furious, angry, or venomous. In some parts of England and in the United States particularly, it is still used in this sense. Atter was the Anglo-Saxon name for an adder, or viper. The proverbial saying has therefore probably no reference to hat-makers, but merely means 'as venomous as an adder.' The Germans call the viper Natter.

As does this 1895 entry from Beckwith's Almanac, which cites the Brooklyn Eagle as its source:

The phrase "mad as a hatter" has no reference to that respectable artist who designs the crowning article of civilized male attire, but relates back to the Anglo-Saxon word "atter" (an adder or viper). "Mad" was formerly used as a synonym for violent or venomous and is still used in that sense in some parts of England as well as in this country. The phrase, therefore, strictly means as "venomous as a viper," the old form, "mad as an atter," having been corrupted to "mad as a hatter."

A sharp-eyed reader spotted this very early sighting of "mad as an adder" in an 1842 publication:

He was as mad as a striped adder.

Whether Carroll meant his "hatter" as a caricature of a known crackpot, a play on mad as a March hare, as a bit of tomfoolery about venomous vipers, or as a combination of all three, it seems clear that the only relation his use of the term had to mercury-maddened hat makers was that of coincidence.

Barbara "mercury rising" Mikkelson

Last updated:   18 May 2010

  Sources Sources:

    Beckwith, George [editor].   "Mad as a Hatter."

    Beckwith's Almanac.   Vol. 48, 1895   (p. 89).

    Edwards, Elizer.   Words, Facts, and Phrases.

    London: Chatto and Windus 1882   (p. 347).

    Phyfe, William Henry P.   5,000 Facts and Fancies.

    New York: Putnam, 1901   (p. 362).

    Rawson, Hugh.   Devious Derivations.

    New York: Crown Trade Paperbacks, 1994.   ISBN 0-517-88128-4   (p. 135).

    Ward, Philip.   A Dictionary of Common Fallacies.

    New York: Oleander Press, 1980.   ISBN 0-900891-65-3.

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