We’ve all heard the phrase “mad as a hatter” before, but have you ever wondered about the Mad as a Hatter origin and why they go mad?  The phrase is rooted in the hat-making industry’s dark past. In the 18th and 19th centuries, hatters frequently worked with mercury, a toxic element, during the process of felting. The term “mad hatter” was coined as a result of these symptoms and has since become synonymous with eccentricity and madness and mad hatter disease.

Mad as a Hatter Origin

The phrase “mad as a hatter” predates Carroll’s novel and has its roots in the hat-making industry of the 18th and 19th centuries. Hat-makers, or hatters, were exposed to toxic mercury compounds during the process of turning animal fur into felt for hats. The use of mercury in hat-making was common until the early 20th century when it was replaced by safer alternatives.

Mad as a Hatter Origin

Mercury Poisoning

The use of mercury in the hat-making industry was widespread due to its ability to quickly and efficiently turn animal fur into felt, a crucial component of many hats. The process, known as “carroting,” involved treating fur with mercuric nitrate, creating a vibrant orange color that made it easier to work with. However, this technique exposed hatters to dangerous levels of mercury, resulting in the onset of mercury poisoning.

Erethism, also known as “mad hatter syndrome,” is the medical term for the neurological and behavioral symptoms associated with mercury poisoning.


Prolonged exposure to mercury caused various physical and mental health issues, including tremors, memory loss, irritability, depression, and even hallucinations, which eventually led to the phrase “mad as a hatter.” These are the symptoms of mad hatter disease, but it is mandatory to consult a specialist before reaching any judgment. The phrase was used to describe the erratic behavior and mental instability that many hatters exhibited as a result of mercury poisoning. 

The severity of these symptoms varied from person to person and often worsened over time as mercury exposure continued.

why did hatters go mad

Famous Hat Makers in History

John Batterson Stetson

One of the most well-known hatters in history is John Batterson Stetson, who founded the Stetson Hat Company in the 19th century. Stetson’s signature cowboy hat, the Stetson Boss of the Plains, is still popular today and has become synonymous with the American West.

Stephen Jones

Another prominent figure in the world of hat-making is British milliner Stephen Jones. Known for his innovative and avant-garde designs, Jones has worked with numerous fashion houses and celebrities, solidifying his status as a leading figure in the industry.

The Mad Hatter: A Literary Figure

Mad as hatter Alice in Wonderland

The character we know today as the Mad Hatter first appeared in Lewis Carroll’s 1865 novel, Alice’s Adventures in Wonderland. Carroll never explicitly referred to the character as “mad,” but the Hatter’s erratic behavior and bizarre conversation patterns left no doubt that he was indeed a little off-kilter.

The Mad Hatter’s Tea Party

One of the most iconic scenes in Alice’s Adventures in Wonderland is the Mad Hatter’s Tea Party, which has become synonymous with chaos and confusion. During this scene, Alice encounters the Mad Hatter, the March Hare, and the Dormouse as they engage in nonsensical conversation and riddles that leave her exasperated and disoriented.

Lasting Impact Of Mad as a Hatter Mercury

Though the use of mercury in hat making has long been discontinued, the legacy of “mad as a hatter” lives on in popular culture and language. The phrase serves as a cautionary tale of the dangers of hazardous materials in the workplace and a reminder of the sacrifices made by those who labored in the name of fashion. As we appreciate the beauty and craftsmanship of hats throughout history, let us also remember the human cost behind their creation.

Popular Adaptations of the Mad Hatter

Mad as Hatter- Alice in Wonderland

Film and Television

The Mad Hatter has been adapted and reimagined in various film and television productions over the years. From Disney’s classic 1951 animated film to Tim Burton’s 2010 live-action adaptation, the character continues to capture the imagination of audiences worldwide. Notable portrayals of The Mad Hatter include Ed Wynn’s whimsical performance in Disney’s animated version and Johnny Depp’s darker interpretation in Burton’s film.

Disney's classic 1951 animated film to Tim Burton's 2010

Theater and Musicals

The character has also found its way onto the stage in various theatrical productions and musical adaptations. From Alice in Wonderland ballets to the Tony Award-nominated Broadway musical Wonder Land, the Mad Hatter continues to entertain and bewilder audiences with his eccentric antics.

Mad as a Hatter Idiom Sentence

“Mad as a hatter” is a versatile idiom that can be used in various contexts. Here’s an example of how the phrase can be used in a sentence: “After pulling an all-nighter to finish her project, Susan was as mad as a hatter, laughing and talking to herself as she stumbled into the office.”

Mad as a Hatter Synonyms

The popularity of the phrase “mad as a hatter” has given rise to several synonyms that convey similar meanings. Some of these alternatives include “crazy as a loon,” “bats in the belfry,” and “nuts.” While these idioms may differ in their specific imagery, they all evoke a sense of irrational or erratic behavior.

Alternative Explanations for the Phrase

While the hat-making industry and mercury poisoning are widely accepted as the origins of the phrase “mad as a hatter,” some alternative explanations have been proposed. Some linguists and historians argue that the phrase might have originated from the Anglo-Saxon word “atter,” which means poison or venom, while others suggest that it could be linked to the ancient Roman god Mercury, who was often depicted wearing a hat.

Mad Hatter Disease Treatment

During the height of the hat-making industry, treatment options for “mad hatter disease” were limited. Affected hatters often sought relief through various remedies, including the use of chelation agents like British Anti-Lewisite (BAL), which binds to mercury and helps remove it from the body. However, these treatments were not always effective, and many hatters succumbed to the long-term effects of mercury poisoning.


The origin of the phrase “mad as a hatter” offers an intriguing glimpse into the world of hat-making, literature, and popular culture. From Lewis Carroll’s Alice’s Adventures in Wonderland to modern film adaptations, the Mad Hatter has captured our imaginations for over a century. As we continue to use and reinterpret this idiom, it is important to remember its historical roots and the lessons it can teach us about the consequences of human activity on our health and the environment.