Age of Invention: Knowledge Lost and Found

Was medicine in the past really quite so bad?

You’re reading my newsletter, Age of Invention, on the causes of the British Industrial Revolution and the history of innovation. The free edition currently goes out to over 6,650 people. You can sign up here:

We’re very used to mocking the obscure-sounding remedies of our distant ancestors. It’s hard to take them seriously when their go-to remedies were to remove some blood or take a horoscope. Or, if you were wealthy, to swallow concoctions containing emeralds, sapphires, or obscure animal parts. With the benefit of hindsight, the trajectory of medical improvement seems obvious and linear, as we became attuned to the benefits of hygiene, introduced anaesthetics, and identified the real causes of disease.

But in some ways hindsight is misleading. Our ancestors may not have always understood why things worked, but they were often surprisingly good at finding things that actually did work — but which were discarded prematurely by the onward march of science, when everything we thought we knew was put to the test. Some sixteenth-century alchemy actually got results. The mechanical ventilation of confined spaces, albeit invented by following the erroneous idea that noxious airs caused disease, appears to have inadvertently saved lives. And long before germ theory became the dominant model of disease, many cities on the Mediterranean had special areas or islands — Lazarettos — to quarantine arrivals from plague-ridden ports.

Even the most outrageous of remedies could have something to them. Physicians once prescribed mercury to treat syphilis, effectively the HIV/AIDS of the early modern world, which in the late eighteenth century may have affected one in five Londoners. But mercury, albeit poisonous, appears to have worked along the same lines as chemotherapy, hopefully killing the disease before the cure killed the patient. It could be effective, though probably only under certain conditions. In the 1880s mercury was switched out for bismuth salts, which worked similarly — bismuth is a heavy metal, but far less toxic to humans than it was to the disease. Even the anti-syphilitic wonder drugs of the early twentieth century, Salvarsan and Neosalvarsan, were toxic compounds of arsenic, albeit far less unpleasant. Treating the disease successfully was often a matter of picking the right poison.

Syphilis, along with a host of other bacterial diseases, was finally conquered with the use of newly-discovered antibiotics like penicillin in the 1940s. But antibiotics actually have a much longer history — even if nobody understood how exactly they had worked.

Yesterday while continuing to read through a book on 1630s trade, which I mentioned last week, I noticed a stray mention of a clay once exported from the Aegean island of Lemnos. By the seventeenth century its export was tightly controlled by the Ottoman sultans who ruled the region — it was a good source of revenue — but the clay had been popular since ancient times as a cure-all for various diseases and poisons. Known as terra sigillata, or stamped earth, it had in ancient times been stamped with a head of Artemis, and by the seventeenth century with the sultan’s seal. Thanks to the Ottoman monopoly over the Lemnian clay, various other stamped cure-all earths were soon identified in England, Ireland, France, Florence, Spain, Portugal, Armenia, Malta, and the Baltic. Perhaps thanks to this proliferation, however, by the eighteenth century people began to become sceptical of their efficacy, and advances in chemical analysis then put an end to them. Lemnian clay, disappointingly, turned out to just be clay.

But the nineteenth-century scientists seem to have got it wrong. Just last year, teams of scientists and archaeologists published analyses of various terra sigillata at the Pharmacy Museum at the University of Basel. They discovered that some of them actually had antibacterial properties after all.

The key thing was seemingly not the clay itself, but its ritual treatment. In ancient times this involved priestesses of Artemis mixing the mud with water and leaving it, before drying it out and applying the stamp; in the fifteenth and sixteenth centuries it was similarly covered with spring water and left to stagnate, or else dug at certain times of the year, only to a shallow depth, or from particular areas close to water. Thanks to recent advances in DNA-sequencing, we now know why: the ritual treatment of the clay appears to have introduced a fungus closely related to Penicillium, called Talaromyces, which produced an antibacterial and antimalarial called bioxanthracene B. It seems our ancestors who bought and used the clay were not being taken for fools after all.

Excitingly, the researchers have discovered that some of the other kinds of terra sigillata are also antibacterial — the Armenian boles, for example, are effective against more kinds of bacteria than the Lemnian earth, though it’s not yet clear why. And there are plenty of other terra sigillata yet to be tested using the new methods. What nineteenth-century chemical analysis too hastily took away from us, twenty-first century DNA-sequencing may soon give us back. The history of medicine is not so linear after all.

P.S. This week, as a one-off taster, I’ve shared this paid edition of the newsletter for free. Paying subscribers get this post every other week. Recent ones you may have missed include how we get almost everything about the enclosure movement wrong, and on how inventors have rebranded themselves over the centuries.

Students and others on low incomes can become subscribers at a discount here.