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Mad Hatter's Syndrome: How Milliners Went Mental

Lilith holds bachelor's degrees in anthropolgy and history. She enjoys exploring historical peculiarities through research and writing.


The Unordinary Life of an Extraordinary Man

In the mid-1800s, a young, often described as “different”, hat maker chose -as so many at the time did- to give his life over to the Lord, becoming a born-again Christian while living in Boston. Okay, so maybe he didn’t commit himself to Christ quite like his peers, considering he purposefully styled his appearance to emulate that of Jesus (as depicted in Western culture) and castrated himself. No, no: you read that instance of rapid escalation correctly. This same man, propelled by divine Providence, later joined the Union army during the Civil War. Post-combat, he returned to the hat industry, but soon relocated to Kansas, where he chose to relegate himself to a stone-walled dugout in the side of a hill, armed with a myriad of guns, a flock of sheep, and an abundance of religious rantings, for which he became notorious in the immediate community.

A few years later, plagued by overwhelming paranoia, he was committed to a mental asylum after brandishing a firearm at the local statehouse. He escaped his confinement less than a year later; his life and eventual demise thereafter remains a mystery.

Portrait of Sgt. Boston Corbett in the Union Army

Portrait of Sgt. Boston Corbett in the Union Army

Oh, by the way, in the midst of his rather eccentric life (the year 1865, while he was serving in the 16th Cavalry), this same man, named Boston Corbett, killed John Wilkes Booth, the most wanted man in America, assassin of President Abraham Lincoln. The regiment was supposed to apprehend Booth so that he could be questioned (as to his motives) by the government, but Corbett, who believed to have been divinely directed to take the shot, took out the fugitive instead.

An artist rendering of Corbett killing John Wilkes Booth

An artist rendering of Corbett killing John Wilkes Booth

Corbett is a historical figure whose eccentricities would have most certainly been lost to time if it had not been for this singular occurrence that transformed him into a type folk hero. His sudden fame naturally directed people’s attention to accounts of his inherently bizarre behavior and questionable mental state. Later, researchers would look at this patchwork of peculiarity and be able to attribute Corbett’s strangeness to a possible source: hats.

The Highly Dangerous Hat Industry

An image of milliners "carroting" fur to make a hat

An image of milliners "carroting" fur to make a hat

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Oh yes, the unassuming hat; well, at least it is now. Back then, not so much. See, hats, particularly top hats (remember, 1800s in this case), were produced in a rather precarious manner. First, fur had to be separated -while remaining intact- from the skin with a special mixture, which until the 17th century, happened to be comprised mainly of urine. It was then although discovered that mercury (a.k.a. “quicksilver”, a.k.a. “toxic chemical”) could simplify the process. Great, right? That’s going to have to be a hard “no”.

Our compadres from way-back-when, which included Corbett, weren’t too wrapped up in the possibly hazardous consequences that could arise from working intimately and extensively with mercury. Yes, people were aware of the element’s potent power, seeing that it already served medicinal purposes (e.g. treating syphilis), but if it provided the means to an end (and no industrial safety laws prevented its use), well, why not use it? And so, the process of “carroting”, dubbed as such due to the orange color of the mixture, was born, making it way simpler for milliners to manufacture felt…and well, contract mercury poisoning.

The Maddening Effects of Mercury

Fun fact: this metal turns to vapor at room temperatures, which means that the hat makers were inhaling these fumes. Take one or two whiffs, you are probably going to be okay. Sure, you may suffer a bout of diarrhea, some itchiness, a wet cough, muscle pain, and vomiting, but you’ll more than likely recover. However, breathe this stuff in daily, for hours upon hours, and the outlook turns a tad bleaker. Keep in mind that mercury is a neurotoxin, meaning prolonged exposure wreaked havoc on a milliner’s brain, causing him loss of focus, paranoia, hallucinations, memory loss, anxiety, insomnia, tremors from hand to head, jerkier body movements, and possible psychosis.

Not long after mercury became a standard ingredient in hat making, the symptoms of poisoning became so pervasive amongst milliners that in 1829, the phrase “mad as a hatter” (British “mad”, not American “mad”) debuted. While catchy, this idiom was not universal. For instance, the fine folk of Danbury, Connecticut, which was the United States’ hat-making hub during the 18th and 19th centuries, had their own term for the atrocious symptoms of mercury poisoning: the “Danbury Shakes”.

The milliners of Danbury, the hat-producing capital of the United States

The milliners of Danbury, the hat-producing capital of the United States

Eventually, after decades of research on the mad hatter’s syndrome, countries began to enact laws offering protection to hat makers. It took some countries a smidge longer than others to phase out the use of mercury (hydrogen peroxide is now the ingredient of choice). For instance, France got a jump on the legislation in 1898, America not until 1941. Do with that information what you will.

Right, let’s circle back around to Corbett. Is it possible that his aberrant behavior -cue a montage of impulsive actions, delusional ramblings, and paranoid ravings- was the manifestation of mercury poisoning? Did his compromised condition contribute prime him to kill the metaphorical big, bad wolf that was John Wilkes Booth? mean, it’s a possibility, for sure. Just the same, it certainly makes for an interesting story.


This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

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