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160-Year-Old Japanese Medical Kit Contained Deadly Laxative

160-Year-Old Japanese Medical Kit Contained Deadly Laxative


Researchers studying the antique medicine chest of Japanese Edo-era physician, Ogata Koan, discovered enough poison to kill a small army. But why? Koan was a leading a 19th century Japanese medical practitioner and advocate of Western medicine in Japan. As a master of disease pathology he is credited with having built the country's first smallpox clinics, known as Ashimori Joto-kan, and he also established an academy for Western technology and medicine that would become the Osaka University.

An old glass vial containing a mystery white powder was discovered in a medical kit belonging to Ogata Koan and it was recently bombarded with a nanoparticle that generates different light signatures depending on the substrate they are being fired at. It was discovered that the white powder in the bottle was mercuric chloride that the researchers say was not only used as a laxative to treat constipation, it was also used to treat syphilis and other illnesses, and was “highly poisonous.”

The medicine bottle analyzed as part of the Japanese research project revealed that the white powder inside was actually mercuric chloride. (Kyoko Takahashi)

Discovering Ogata Koan’s Deadly Laxative

Researchers at Osaka University analyzed the antique glass vials, that were recovered from Ogata Koan’s medical kit, with “muons.” The muon is an elementary particle classified as a lepton, and similarly to the electron it holds an electric charge, although the muon has a much greater mass. The muon is so small that it is not thought to be composed of any simpler particles, meaning it has no sub-structure, and can be fired through glass producing different kinds of light at the other side.

The antique bottle was scanned with muons at the Japan Proton Accelerator Research Complex (J-Parc), a high-intensity proton accelerator facility in Tokai. Thanks to this technology, the team of scientists were able to confirm that the white power was in fact mercuric chloride. According to an article in Daily Mail, the mysterious white powder was found in the doctors wooden medicine chest along with 21 other glass bottles containing unidentified medicines, each in vials with 3-millimeter-thick glass, that Koan presumably used during house calls. The scientists chose the particular bottle they tested because it was marked with the kanji character for kan, the first of two characters of kanko, or mercuric chloride in English.

Ogata Koan is remembered as the founder of Western medicine in Japan. (Public domain)

Ogata Koan is remembered as the founder of Western medicine in Japan. (Public domain)

Nature Can Both Cure and Kill

A new paper published in the Journal of Natural Medicines explains that X-ray fluorescence testing was used to determine that the bottles were made from lead-potash glass. According to Dr. Asahi Shimbun, who led the new study, while mercuric chloride was a common remedy in the 19th century “used as a laxative and to treat ulcers,” it was also used to treat syphilis. At the time the remedy was popularly known as salts of white mercury, and so it isn’t surprising that they found it in Ogata Koan’s medicine chest.

However, in nature, so often what can cure us can also kill us. Mercuric chloride was also a highly toxic substance. Depending on how the chemical is absorbed, whether swallowed, inhaled, injected or rubbed into the skin, the side effects range from stomach pain and vomiting blood, to burning sensations in the throat and mouth, and even a tiny amount too much could end up in kidney failure. 

Mercuric Chloride: An Ancient Remedy That Can Kill You

The use of mercuric chloride in medicine dates back at least to the Middle Ages when Arab doctors used it to disinfect wounds. According to Britannia, as little as 0.1 grams (0.003 oz) is enough to cause damage to body tissues, “and 2 grams (0.07 oz) can cause death in a 70-kilogram (154 lb) person.” This agent causes extensive tissue damage wherever high concentrations of the poison are encountered, but although mercury chloride, also known as corrosive sublimate, is highly toxic to humans, farmers sometimes dip bulbs and tubers in a solution to kill mildews, molds, and rusts.

Co-author of the new paper, Kyoko Takahashi, said that while mercuric chloride was not used medicinally by itself, it was blended with other medicinal substances as a medicine used to treat patients suffering from strokes and rheumatism-like symptoms. However, perhaps this “deadly-cure” found in Ogata Koan’s medicine chest is best remembered in history after the famed US explorers, Lewis and Clark, took laxatives laced with mercuric chloride to treat constipation, resulting in chronic diarrhea.

Top image: Analysis of the medicine kit of Ogata Koan has revealed that it contained large quantities of deadly mercuric chloride. Source: Kyoko Takahashi

By Ashley Cowie

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Ashley is a Scottish historian, author, and documentary filmmaker presenting original perspectives on historical problems in accessible and exciting ways.

He was raised in Wick, a small fishing village in the county of Caithness on the north east coast of... Read More

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