A Mercurial Toxin

Since ancient times, compounds containing mercury have been used in the treatment of skin diseases and other ailments. However, mercury toxicity was not fully appreciated until March 8, 1809 when two British ships, the HMS Triumph and HMS Phipps, came to the rescue of a Spanish ship that had been damaged in a hurricane. They rescued the crews and transferred the valuable cargo of mercury. Within weeks, the crews began to experience the effects of mercury poisoning, eventually many were hospitalized and some died.

Mercury was known to ancient peoples and was even found adorning a 15th century BCE ceremonial cup in an Egyptian tomb. Aristotle authored the earliest record of what he called "fluid silver" or quicksilver in the 4th Century BCE. Mercuric chloride, calomel, was used as an antiseptic to kill bacteria while mercuric sulfide is used to make the bright red vermillion paint. Mercury was also commonly used in batteries, fluorescent lights, thermometers, barometers and felt production leading to dementia in those workers and the phrase "mad hatters" coined by Lewis Carroll in Alice in Wonderland. Mercury has been used to extract gold and silver by a process of amalgamation. The Spanish ship was transporting mercury to South America for the extraction of silver. On March 16th some of the mercury was transferred into the sloop HMS Phipps. The cargo had been saturated with water leading to rotting containers with several tons of mercury leaking into the lower decks and holds of both ships.

Mercury quickly contaminated everything on the lower decks. Within 3 weeks, mercury poisoning appeared among the crews. Symptoms of mercury poisoning were excessive saliva secretion, mouth ulcerations, and partial paralysis as well as lung and bowel complaints. At an estimated temperature below decks of 68 degrees F, the saturation point of mercury would have been 140 times the maximum allowable concentration. Those with the highest exposure, some of whom later died, suffered from dramatic swelling of their heads and tongues, lost their teeth and suffered from gangrene of the face and tongue. By mid-April, 200 men, one third of the crew, showed signs of mercury poisoning. On April 22nd, the men were transferred to hospital ships and the Triumph was inspected by four fleet surgeons. The Triumph was a large 79 gun ship of the line. The very different structure of the sloop HMS Phipps lessened the impact of mercury on board, though some of her sailors were also affected. The Triumph was cleaned and returned to service in June only to have fresh cases of mercury poisoning appear. By June 13th, she was ordered to sail home to England which took 40 days and despite numerous precautions, additional men became ill, but the symptoms were not as severe. The Triumph was emptied and little is known about her fate other than she became a quarantine ship before being broken up in 1850. Though poisoning with mercury was known, accidental poisoning by mercury vapor was rare and the incident on the Triumph is unique in the history of toxicology. It gave everyone a fuller appreciation for the dangers of mercury poisoning.

Medical Discovery News is hosted by professors Norbert Herzog at Quinnipiac University, and David Niesel of the University of Texas Medical Branch. Learn more at www.medicaldiscoverynews.com.