There’s a famous story relayed by Pliny the Elder in his Natural History that Cleopatra drank the largest pearls in the world dissolved in vinegar on a bet with Marc Antony.

There were formerly two pearls, the largest that had been ever seen in the whole world: Cleopatra, the last of the queens of Egypt, was in possession of them both, they having come to her by descent from the kings of the East. When Antony had been sated by her, day after day, with the most exquisite banquets, this queenly courtesan, inflated with vanity and disdainful arrogance, affected to treat all this sumptuousness and all these vast preparations with the greatest contempt; upon which Antony enquired what there was that could possibly be added to such extraordinary magnificence. To this she made answer, that on a single entertainment she would expend ten millions of sesterces. Antony was extremely desirous to learn how that could be done, but looked upon it as a thing quite impossible; and a wager was the result. On the following day, upon which the matter was to be decided, in order that she might not lose the wager, she had an entertainment set before Antony, magnificent in every respect, though no better than his usual repast. Upon this, Antony joked her, and enquired what was the amount expended upon it; to which she made answer that the banquet which he then beheld was only a trifling appendage to the real banquet, and that she alone would consume at the meal to the ascertained value of that amount, she herself would swallow the ten millions of sesterces; and so ordered the second course to be served. In obedience to her instructions, the servants placed before her a single vessel, which was filled with vinegar, a liquid, the sharpness and strength of which is able to dis-solve pearls. At this moment she was wearing in her ears those choicest and most rare and unique productions of Nature; and while Antony was waiting to see what she was going to do, taking one of them from out of her ear, she threw it into the vinegar, and directly it was melted, swallowed it.

It hasn’t been taken terribly seriously by historians because as you can see, Pliny deploys the story more as an illustration of Antony and Cleopatra’s dissipated, luxurious wastefulness than a realistic description. Besides, a basic test of the tall tale fails: if you drop pearls in vinegar, even highly acidic vinegar, they don’t melt. At least not right away like they do in Pliny’s story.

Classicist Prudence Jones of Montclair State University decided to explore the pearls-in-vinegar possibilities. She didn’t discount the story as fiction off the bat, especially since Cleopatra was said by ancient physician Galen to be well-versed in poison lore. She also wrote a book on cosmetics — fragments of which still exist — displaying an extensive knowledge of chemistry.

Jones began experimenting with calcium tablets, then oyster shells in vinegar. Then in a shocking break, a jeweler gave her two 5 frikkin carat pearls to test.

“Experiments reveal that a reaction between pearls and vinegar is quite possible,” concludes the study. Calcium carbonate plus the vinegar’s acetic acid in water produces calcium acetate water and carbon dioxide, for chemistry fans. Jones finds a 5% solution of acetic acid, sold in supermarkets today and well within concentrations produced naturally by fermentation, takes 24 to 36 hours to dissolve a 5-carat pearl. Boiling the vinegar, or crushing the pearl, or both, greatly speeds up the reaction, perhaps to under 10 minutes. Interestingly, stronger solutions of acetic acid greatly slows down dissolving (the water takes part in the reaction), something that may have hindered folks testing Pliny’s veracity in the past.

So the straight from earring to vinegar then down the hatch process either didn’t happen, or Cleopatra fixed the bet by softening the pearl for a day or two before wearing them at dinner, or she had the vinegar boiled before dropping in the pearls. I could totally see her hustling Marc Antony like that.

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