Over the past few months, as I learned more and more about the use of quicksilver in eighteenth-century chemistry and medicine, I became increasingly curious about the origins of all this mercury. The chemistry of the eighteenth century was a science of materials, materials that allowed various ways of inquiry: descriptions were made, technological possibilities explored and philosophical reasoning applied. However, we should not forget that in early classical chemistry, all chemical substances were useful materials produced in mining, metallurgy and pharmacy.[1] So where did a useful chemical material like mercury come from? In his book De Mercurio Experimenta, Boerhaave mentioned that he acquired sixteen ounces of quicksilver for his experiments at ‘the Company at Amsterdam.‘^[1]

That must have been one famous company, if Boerhaave only needed to refer to it as ‘the Company at Amsterdam’ in the transactions of the Royal Society. It was indeed. I soon found out that at the time Boerhaave was writing this, the company of the Amsterdam Deutz family had almost exclusive rights to the trade in mercury in the Low Countries, and even in Europe. The most important quicksilver mines in Europe were those in Idria in the Habsburg Empire (now in Slovenia and spelled Idrija).

In the mid-seventeenth century, the Habsburg emperor monopolised the entire mercury mining and trade business of Idria, and in 1669 appointed a limited number of ‘factors’ in Venice and Amsterdam, who had the exclusive right to trade the imperial mercury. This situation would persist more or less unchallenged until 1741.^[2]

The Amsterdam factor was Jean Deutz (1618-1673), a rich merchant originally from Cologne. After his death, first his son Jean (1655-1719) and subsequently his grandson Willem Gideon (1697-1757) took over the factorship. Because of the their monopoly, Amsterdam was the international trade centre for mercury, and the production centre of vermilion (a red dyestuff produced from sulphur and mercury) and mercurial salts in Boerhaave’s time. Although local apothecaries and assayers would also stock mercury, for the relatively large amount of pure mercury Boerhaave required – 16 ounces, which, in today’s weight, would be almost 500 grams -, the Amsterdam company was apparently the most trusted supplier.

However, in Deutz’s perspective, 16 ounces was hardly business. Mercury was used in

much larger quantities in all kinds of industries, such as felting (done by hat makers who frequently suffered mercury poisoning, hence the expression ‘mad as a hatter’), glass and mirror making and the dye industry. But the price of mercury was largely defined by the demand of the mining industry, as mercury was used to mine gold and silver.[3] Deutz gave massive loans to the Emperor, in return for which he would receive a set amount of mercury each year, which he sold for huge profits. Around 1706, when the Amsterdam monopoly was somewhat shaken by English imports of mercury from China, the sales of eight hundred 150 pound kegs of quicksilver a year still supplied the Deutz company with an annual income of about 225,000 guilders.^[4]

As mentioned in previous posts, I am working on a project on mercury in eighteenth-century chemistry and medicine. Over the past few weeks, I have been researching the use of mercury as a drug in eighteenth-century Britain and the Netherlands, and I found some fascinating yet disturbing stories.

In the early eighteenth century, England was the scene of what would go down in history as the ‘Quicksilver Controversy.’ For centuries, mercury and mercury preparations had been used to cure all kinds of intestinal blockages and venereal disease. However, most physicians were well aware of the potential dangers of mercury, and prescribed it only if all else failed. Not Thomas Dover (1662-1742), alias the Quicksilver Doctor. Unlike his contemporaries, he believed crude mercury to be a cure-all for all kinds of blockages. Although he was vehemently opposed by many of his colleagues, there were enough people desperate enough to try his ‘cure.’

To which this could lead was shown in the case of Barton Booth (1681-1733), one of the most famous tragedy actors of his time.

From 1727, Booth was afflicted by ill health: it began with a fever lasting forty-six days, followed by returning bouts of jaundice. Desperate for a cure, Booth eventually called for Thomas Dover, who prescribed him quicksilver. Within a week, Booth ingested almost two pounds of mercury, and died. When a post-mortem examination was carried out, it was found that Booth’s intestines had turned black and were lined with crude mercury, spreading ‘a most offensive cadaverous stench.’[1]

There are no accounts of other quicksilver doctors as extreme in their views as Thomas Dover,  but popular eighteenth-century literature suggests that the Netherlands too saw quicksilver doctors. In a comedy from 1727 which has been ascribed to the Amsterdam hack writer Gysbert Tyssens (1693-1732), a ‘graduate cobbler,’ Doctor Hans, is ridiculed because he prescribes his patients mercury:

They are very good, ensuring that the sick never have to fear disease again.

Because he will cure them fast with a lethal quicksilver;

And the deceased cannot tell what was the cause of their death;

And in this way Mercury cures all illnesses.[2]

Although most physicians were extremely careful when prescribing mercury, there were clearly also men who were more interested in their own finances than in their patients’ health. Some even used their care for their patients as a pretext; a flimsy cover-up for highly profitable schemes. In the late 1750s, a small pamphlet on a new drug against venereal disease, ‘Helvetische essentie of mercuriale droppels’ (Swiss essence or mercurial drops) was printed in Dutch.

The Dutch translator Ponty, a medical doctor from Rotterdam, states in his introduction that the exact contents of the Helvetian Essence is not revealed in the pamphlet to protect patients from quacks who try to reproduce it. However, the last page suggests an entirely different reason for this secrecy: a two-ounce bottle of this miracle cure sold for 12 Dutch guilders – an amount that would equal over 100 Euros today.[3] The only selling point in the United Provinces? Ponty, the translator.[4]