About two weeks ago, I had coffee with the head of the conservation department of the National Maritime Museum. She asked me if I could mark the bottles and containers from the medicine chests in the database that had potentially hazardous substances in them. As I compiled a list of all the substances and their contemporary uses for my research project anyway, I promised her to do so.

Obviously, many of the substances in the chest can be hazardous if you would swallow an entire bottle at once, but the conservation department is particularly interested in substances that are either a health risk if not properly stored, such as mercury, and substances that are subject to legal regulations, such as opiates. Even if the opium is over a century old, you still need a license to keep it! And as a matter of fact, there are quite some hidden opiates and mercury in the medicine chests.

Some of them are quite easy to recognise, because their label reads something like ‘Hydr.’ (hydrargyrum; mercury), or ‘compound powder of chalk with opium’, and anyone who has ever read a Victorian novel will know laudanum should not be spoon-fed to infants – although one can imagine it would make them very calm. However, others are less straightforward. Grey powder, blue pills, Dover’s powder, paregoric elixir, and calomel or calamel all contain mercury or opium.

Dover’s powder for example, was a traditional medicine against cold and fever developed by Thomas Dover (1660–1742), aka Doctor Quicksilver. Its’ recipe i  Encyclopaedia Britannica: Or a Dictionary of Arts, Sciences and Miscellaneous Litterature of 1810 says:

“Sudorific, or Dover’s powder. E. Take of vitriolated tartar, three drams; opium, root of ipecacuanha powdered, of each one scruple. Mix, and grind them accurately together, so as to make an uniform powder.”

A late nineteenth century bottle of Dover’s Powder – advertised as fever medicine.

But Dover was certainly not the only or the last physician to subscribe mercury-based drugs to his patients. Medication with mercury as the active ingredient was used in the treatment of venereal and skin diseases up to the early twentieth century, and in the nineteenth century they could be found in both traveller’s and family medicine chests in abundance. Turnbull in his 1806 book The Naval Surgeon writes that John Clark  in 1773 was the first to use calomel (mercury chloride) in dysentery in ‘hot countries’.

John Savory, in his 1836 A Companion to the Medicine Chest wrote of calomel: “This mercurial preparation is more extensively and more usefully employed than almost any other article of the Materia Medica. But its principal use is as a purge, conjoined with other aperients; and for this purpose it is administered in doses of from three to six grains, combined with, or followed by, cathartic extract, rhubarb, senna, or other laxatives. (…) In affections of the liver, in various glandular diseases, and in some cutaneous eruptions, calomel is celebrated as an alternative; and, combined with diuretics, it singularly contributes to their activity. (…)..,and in croup no remedy proves so decidedly useful as calomel, in these combinations, administered after bleeding and purging.(…)”

These prescriptions make you wonder to what extent mercury poisoning influenced nineteenth-century society, as it acts as a neurotoxin in the human body, and interferes with the brain and nervous system. In children, it may affect development and cause learning disabilities; in adults it can affect fertility and memory, cause tremors, loss of vision and in severe cases lead to death…

For more on Thomas Dover and quicksilver doctors, see Swiderski, Richard M. Quicksilver : A History of the Use, Lore and Effects of Mercury. Jefferson, NC: McFarland, 2008.