Hektoen International

A Journal of Medical Humanities

Thomas Dover, physician and entrepreneur (1660–1742)

Oh, Dover was a pirate and he sailed the Spanish Main
A hacking cough convulsed him and he had agonizing pain.
So he mixed himself a powder, which he liked more and more.
Ipecac and opium and K2SO4 1


Dover Powder, U.S.P., 1920. Produced by and gift of Parke, Davis and Company. National Museum of American History, catalogue number M-01067. Smithsonian Institution. Fair use.

Thomas Dover was an English physician who in 1732 invented a patent medicine known as “Dover’s Powder.” It consisted of opium, ipecacuanha, and lactose, was widely used for relieving coughs, colds and pain, and remained popular for many years.2-3 Used extensively by the armies during the United States Civil War and World War Two, it was available in Britain until the 1960s and in India until 1994.2 However, it was addictive because of its opium content and was toxic if taken in large doses.

Its inventor, Thomas Dover, has been described as “obstinate, boastful, and quarrelsome, but generous to the poor, devoted to his friends, and venturesome.”3 Born in 1660 in a small town in Warwickshire, he obtained his medical degree in six years from Oxford University, then moved to Cambridge “possibly because of the distinction of the master of the college.”2 After leaving Cambridge he studied and worked in London under the distinguished physician Thomas Sydenham, becoming his house pupil. When Dover contracted smallpox, Sydenham treated him with his cooling system (bed clothes no higher than the waist, purging, bloodletting, and daily twelve bottles of weak beer with added spirit of vitriol or dilute sulphuric acid).2 He recovered, having also learned the value of opium as medicine.

Not being licensed to practice in London, he did so successfully in Bristol, then a thriving commercial city, a center of fashion, and a popular spa.3 He developed a successful practice and became wealthy, but also took care of the poor inmates of the local workhouse. During the War of the Spanish Succession against France and Spain, he financed lucrative privateering expeditions to plunder Spanish ships and settlements in South America. Between 1708 and 1711 he himself went on a three years’ expedition, acting as the president of the council of senior officers, deciding strategy and resolving disputes, and as ship’s doctor treating smallpox, plague, dysentery, and typhus. Some forty years before James Lind, he was already aware that scurvy could be prevented by fresh produce.

Dover’s expedition started in Bristol. His two ships, The Duke and The Duchess, first headed to the Canary and Cape Verde Islands, then to Brazil. Sailing through Cape Horn, they reached Peru, Ecuador, the Galapagos Island, and the southern tip of California. Then they sailed to Guam, to present day Indonesia, and to Cape Town, returning to England in October 1712 after a most profitable expedition.

One interesting benefit of the expedition was that it probably served as inspiration for Daniel Defoe’s most famous novel Robinson Crusoe. While landing on Juan Fernandez Island, about 400 miles of the Chilean coast, the crew saw a fire and the next day encountered a wild looking hairy man wearing goat skins. Called Alexander Selkirk, he was a Scotsman who had been marooned on the island for four years after quarreling with the captain of his ship: “He had with him his Clothes and Bedding, with a Firelock, some Powder, Bullets, and Tobacco, a Hatchet, a Knife, a Kettle, a Bible, some practical Pieces, and his Mathematical Instruments and Books.”3

After returning from his voyage, Dover set up practice in London. He specialized in treating digestive disorders and gout (for which he prescribed a purge, the application of raw beefsteak, and “a very pleasant sudorific,” his famous powder.) He adopted a wealthy lifestyle and built a large mansion called Dover House. In 1719 he published a self-laudatory book called the Ancient Physician’s Legacy to his Country in which he reviewed 120 diseases. The book was written for the general public (“Designed for use of all Private Families”) and was available in coffeehouses, stressing self-diagnosis, containing letters from grateful patients, and attacking his competitors. After moving to Gloucestershire for a few years, he returned to London and became known as Doctor Quicksilver for frequently prescribing mercury for asthma, worms, colic—and in a larger dose for intestinal obstruction to secure “free passage” through the body. For tuberculosis he recommended frequent bleedings in small quantities, differing from his old chief Sydenham, who “wonderfully commends Riding in this Distemper.”3 At one time Dover also invented a blowpipe for resuscitating drowning victims. He continued to practice medicine in London until 1728. His book went through eight editions and was last republished in 1742, the year when he died at the age of eighty, immortalized by his famous powder.



  1. The Cambridge History of Medicine 2006, edited by Roy Porter, p. 217.
  2. Jangu Banatvala. Thomas Dover: doctor, privateer, and rescuer of Robinson Crusoe. BMJ Dec 14, 2016;355:i6516.
  3. DN Phear. Thomas Dover 1662-1742. Physician, Privateering Captain, and Inventor of Dover’s Powder. Journal of the History of Medicine and Allied Sciences April 1954;9(2):1339.



GEORGE DUNEA, MD, Editor-in-Chief


Summer 2023  |  Sections  |  Physicians of Note

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