Sunday, 25 December 2016

Thomas Dover: doctor, privateer, and rescuer of Robinson Crusoe

Christmas 2016: In the Literature

BMJ 2016; 355 doi: (Published 14 December 2016) Cite this as: BMJ 2016;355:i6516

  1. Jangu Banatvala, emeritus professor of clinical virology
    Author affiliations
Jangu Banatvala recounts the remarkable adventures of Thomas Dover
Dover’s Powder was introduced in the 19th century as a treatment for febrile illnesses and other ailments. The originator of the powder, Thomas Dover, was a man of many parts—doctor, privateer, rescuer of Alexander Selkirk (the inspiration for Daniel Defoe’s Robinson Crusoe), fashionable London physician, popular medical author for the general public, and self publicist.

Dover’s Powder

My father, a London GP, used to prescribe Dover’s Powder for me when I had various mild childhood febrile illnesses. This was probably common practice before and during the second world war. The preparation was a mixture of ipecacuanha, powdered opium, and lactose. It was available in Britain until the 1960s and in India until as recently as 1994. In many ways Dover’s Powder was an ideal preparation, its opium content having analgesic and soporific properties and a small dose of ipecacuanha having expectorant properties. However, opioid derivatives came to be considered unsuitable for minor illnesses, particularly for children. Dover’s Powder was used extensively during the American civil war, by Italian troops in the western desert, and during the second world war by the navy, in the coxswain’s box of medicines that was supplied to destroyers and smaller ships.1

Dover’s early years

Dover took his first degrees (bachelor of arts and then master of arts) in Oxford and then went to Gonville and Caius College, Cambridge, possibly because of the distinction of the master of the college, Robert Brady, who was regius professor of physic and a friend of Thomas Sydenham’s, a doctor who practised in Pall Mall. Sydenham was regarded as the English Hippocrates because of his ability to accurately record the natural history of disease. Dover became the house pupil of Sydenham and learnt the value of opium as a medication.2
While studying with Sydenham, Dover caught smallpox. Sydenham’s treatment consisted of cooling (no bed clothes and open windows), bloodletting, purging, and copious weak beer with “spirit of vitriol” (sulphuric acid). Not only did Dover recover, but he used this therapy on his patients, including seafarers. Surprisingly, many survived, although they may have had the milder strain (alastrim).
Dover’s bachelor of medicine was not recognised for practice within six miles of Westminster; for this a licence had to be obtained from the Royal College of Physicians. So Dover set up practice in Bristol; a thriving, wealthy city and a major sea port. About two thirds of Dover’s patients sought advice for fevers, most of which are now rare in the developed world, but many were, and still are, commonly encountered in developing countries. Many of Dover’s patients would have been sailors and traders, who caught infections or experienced trauma on long voyages to distant lands. Dover became wealthy in Bristol, but he also took care of the inmates of a workhouse (St Peter’s Hospital) free of charge.3

From physician to privateer

Unlike many wealthy merchants Dover not only financed privateering expeditions but also set out himself to plunder enemy ships and coasts. Privateering expeditions were aimed at shortening the war of Spanish succession (1701-14) by attacking the enemy’s commercial interests, particularly Spanish galleons.
He helped finance one of the most remarkable voyages, which was not only very long (over three years, starting in August 1708), but was also nearly free of accidents because it was so well prepared. The voyage accumulated more prize money than any comparable expedition in maritime history, and Dover took an active role. The voyage started with two ships, The Duke and The Duchess, and the expedition had a well respected, though young, commander—Captain Woodes Rogers (aged 29). William Dampier, a pilot and experienced navigator who had twice circumnavigated the globe, was also on board. Their route took them through the Atlantic to Cape Horn, along the South American coast, and across the Pacific (fig 1).4
Fig 1 The route of Dover’s voyage. Modified from Wikimedia. Source: Urnanabha.
The ships were remarkably small, with a keel of about 80ft and a 25ft beam. Built for speed, they were poorly equipped for long distances and had crews of just over 100 people.5 Dover was the ships’ doctor and president of the council of senior officers, deciding strategy and resolving disputes. He was also in charge of landing and boarding parties. The cramped conditions were ideal for the transmission of infectious diseases, such as smallpox, plague, dysentery, typhus, and arthropod-borne infections. Scurvy was a perennial problem on particularly long voyages, where fresh produce was unavailable. Unlike many seafarers, Rogers and Dover were aware that fresh produce was both preventive and curative for scurvy some 40 years before James Lind’s classical experimental studies.

Inspiration for Robinson Crusoe

One day the crew of The Duke saw a fire on one of the islands of Juan Fernandes, about 400 miles off the Chilean coast. Despite advice not to pursue, lest there were Spaniards, Dover took a party of eight to investigate. They found a hairy, wild looking man, clothed in goat skins: Alexander Selkirk, a Scotsman. The only other inhabitants of the island were goats and cats, left behind by previous ships; there was no Man Friday nor eight desert island discs.
Selkirk had been marooned there for four years having quarrelled with the captain of his ship about its seaworthiness. Selkirk was right—that ship sank with major loss of life. Dampier knew of Selkirk’s navigational ability and appointed him TheDuke’s mate.
The voyage lasted for three years and three months. We don’t know whether Daniel Defoe met Selkirk or Dover, but Defoe was obviously captivated by Selkirk’s widely publicised story and may have read Rogers’ account of the voyage, A Cruising Voyage Round the World, which was published in 1712. In 1719 Defoe’s work The Life and Surprising Adventures of Robinson Crusoe was published.

Dr Quicksilver

After returning to England in October 1711 Dover took a prolonged vacation in eastern Europe and Anatolia. While there he became convinced of the value of mercury as therapy for a variety of ills.6 He was known as “Dr Quicksilver,” but whether any of his patients developed mercury poisoning is not recorded. Perhaps they died before the link could be established.
Dover was initially wealthy as a privateer but lost most of this money in the “south sea bubble.” He settled his debts by selling his inherited family estates. To accumulate wealth again Dover was keen to establish himself as a doctor with a lucrative London practice. Aged 61 he obtained a licence from the Royal College of Physicians, but this was hindered with bureaucracy. Firstly his bachelor of medicine certificate could not be found, then an examiner failed to appear, and, finally, the key for the container for the diploma seal was lost. He practised in some of the more fashionable parts of London, behaving pompously and being overtly critical of his colleagues.
He published his book The Ancient Physician’s Legacy to his Country in 1719, reviewing 120 diseases and running to eight editions. This was aimed at the general public and directed towards self diagnosis. It was available in most coffeehouses; perhaps it was a predecessor of the internet. This self laudatory book contained letters from grateful patients and polemics against his fellow physicians and apothecaries. He thought that apothecaries grossly overcharged and that his college was a “clan of prejudiced gentlemen.”3 The General Medical Council did not yet exist, but Dover’s conduct was chastised by the Royal College of Physicians, the president of which was his student contemporary Hans Sloane.
Dover spent his declining years in the village of Stanway near Cheltenham. He died in April 1742, but, despite his adventures and the lasting popularity of Dover’s Powder, there are no memorials to this remarkable man. Before we are too critical of the standards of medicine in the early 18th Century, we should ask what our successors will say about our practice and behaviour in 300 years’ time.


  • Competing interests: I have read and understood BMJ policy on declaration of interests and declare that I have no competing interests.
  • I am grateful for advice from Dr Tim Beattie, a maritime historian, Dr D N Phear, retired physician, The Middlesex Hospital, Dr J Banatvala, Southbank University, and Madeleine Banatvala, Queen Mary College, Paris.