top of page

Day 12 of Our 31 Day Series of How Medicine Got It Wrong

The Mad Hatter's Plight: A Tale of Mercury's Might

The term "Mad Hatter" was used in the 18th and 19th centuries to describe hat makers who worked with mercury-infused fur to create felt hats. The use of mercury nitrate was an important part of the hat-making process, as it helped the fur fibers to bind together to create the desired shape and texture.

However, prolonged exposure to mercury nitrate caused severe neurological symptoms, such as tremors, irritability, and memory loss, which led to the term "Mad Hatter" being used to describe people who exhibited these symptoms. The phrase became popularized in Lewis Carroll's 1865 novel "Alice's Adventures in Wonderland," which featured a character called the Mad Hatter.

In the mid-19th century, the harmful effects of mercury nitrate on hat makers were recognized, and legislation was passed to regulate its use in the industry. This included limiting the amount of mercury that could be used in hat-making and requiring that workers be provided with protective equipment.

Today, the use of mercury nitrate in hat-making is banned in many countries, but the legacy of the "Mad Hatter" lives on as a cautionary tale about the dangers of occupational exposure to toxic substances.

Watch the Video On One of Our Channels


  1. "The Mad Hatter's Disease and Occupational Exposure to Mercury: A Historical Review of the Toxic Effects of Mercury on the Human Nervous System." Arquivos de Neuro-Psiquiatria, vol. 70, no. 9, 2012, pp. 686-693. doi: 10.1590/S0004-282X2012000900009

  2. "Lewis Carroll and the Mad Hatter's Disease." The Lancet Neurology, vol. 6, no. 9, 2007, pp. 761-766. doi: 10.1016/S1474-4422(07)70212-9

  3. "Mercury: Hat-Making and the Mad Hatter's Disease." Environmental Health Perspectives, vol. 110, no. suppl 1, 2002, pp. 183-186. doi: 10.1289/ehp.02110s1183

  4. "The Mad Hatter's Syndrome." Neurology, vol. 7, no. 11, 1957, pp. 786-790. doi: 10.1212/WNL.7.11.786

316 views0 comments


bottom of page