A very interesting item in USA Today (ultimately deriving from an article in Classical World!) is bouncing around the interwebs … we’ll preface it with this excerpt from Philemon Holland’s 1847 translation of Pliny’s Natural History (9.119-121) via Archive.org. The Latin is available, as always, via Lacus Curtius:

There were two Pearls, the very largest that ever were
known in any Age, and they were possessed by Cleopatra,
the last Queen of Egypt ; having descended to her by means
of the Kings of the East. When Antony had feasted her
Day by Day very sumptuously, and under the Influence,
at one Time, of Pride and petulant Disdain, as a Royal
Harlot, after undervaluing his Expense and Provision, he
demanded how it was possible to go beyond this Magni-
ficence : she replied, that she would consume, in one Supper,
100 hundred thousand Sestertii. 2 Antony desired to learn
how that could be possible, but he thought it was not.

Wagers were, therefore, laid ; and on the following Day,
when the Decision was to be made (for that a Day might
not be lost, Antony appointed the next succeeding one), she
provided a Supper, which was, on the whole, sumptuous ;
but Antony laughed at it, and required to see an Account of
the Particulars. But she said, that what had been served up
already was but the Over-measure, and affirmed still, that
she would in that Supper make up the full Sum ; and her-
self alone consume in this Supper 600 huudred thousand
Sestertii. 1 She then commanded the second Table to be
brought in. As soon as the Order was given, the Attendants
placed before her one only Vessel of Vinegar, 2 the Strength
and Sharpness of which wasted and dissolved the Pearls.
Now she wore at her Ears that most remarkable and truly
singular Work of Nature. Therefore, as Antony waited to
see what she was going to do, she took one of them from
her Ear, steeped it in the Vinegar, and when it was liquefied,
drank it. As she was about to do the like by the other,
L. Plancius, the Judge of that Wager, laid hold upon it
with his Hand, and pronounced that Antony had lost the
Wager : whereat the Man became very angry. The Fame
of this Pearl may go with its Fellow ; for after this Queen,
the Winner of so great a Wager, was taken Prisoner, the
other Pearl was cut in two, that the half of their Supper
might hang at the Ears of Venus, in the Pantheon, at
Rome.

Also of interest, is note on the story:

Cleopatra must have employed a stronger vinegar than that which
we now use for our tables, as the pearls, on account of their hardness and
their natural enamel, cannot be easily dissolved by a weak acid. Nature has
secured the teeth of animals against the effect of acids, by an enamel
covering of the like kind ; but if this enamel happen to be injured only
in one small place, the teeth soon spoil and rot. Cleopatra, perhaps,
broke and pounded the pearls ; and it is probable that she afterwards
diluted the vinegar with water, that she might be able to drink it ;
though it is the nature of the basis or calx to neutralise the acid, and so
render it imperceptible to the tongue. See BECKMAN’S Hist, of Inventions,
vol. ii. p. 1.

This story always reminds me of my Grade 12 biology class, where some poor soul decided to do the ‘Coca-Cola can dissolve teeth) thing as their final project (and it didn’t work, of course) … generally when one hears about Cleo’s pearl, it’s considered one of those urban legends of the ancient world. But check out the excerpts from the piece from USA Today:

[…]

“There’s usually a kernel of truth in these stories,” says classicist Prudence Jones of Montclair (N.J.) State University. “I always prefer to give ancient sources the benefit of the doubt and not assume that something that sounds far-fetched is just fiction.”

In the current Classical World journal, Jones details the history of the story. In it, Cleopatra won a wager with her befuddled Roman consort, Marc Antony, by consuming her pearl cocktail to create the costliest catering bill ever. Her 10 million sesterces (sesterces were the nickels of the ancient world) banquet bill, thanks to the destruction of the pearl, set a pretty early mark on extravagant consumption.

[…]

“I think there was a fairly good understanding of practical chemistry in the ancient world,” Jones says, by email. Fertilizer recipes and preparations to kill parasites on sheep appear, for example, in ancient Roman texts.

Pearls were a popular adornment for the wealthy in the Roman era. Because in antiquity the only pearls in existence were natural ones, they were considerably rarer than they are today, making dissolving one a truly wasteful act. “I think modern scholars dismiss the story more out of disbelief,” Jones says, noting a long line of references, such as a 1940 translation of the story, for instance, that says, “no such vinegar exists.”

The classicist B.L. Ullman of the University of North Carolina noted in 1957 that some experiments suggested that vinegar could indeed dissolve pearls, made of acid-unfriendly calcium carbonate by oysters. But the news never made it to most classicists, says Jones, author of Cleopatra: Life & Times. So, “I began to wonder if there was any truth behind it and started trying some experiments, at first with calcium supplement tablets and pieces of oyster shell and then with pearls,” she says.

To experiment with large pearls, Jones found a jeweler who had a couple of 5 carat ones that had been removed from pieces of jewelry. “They were not perfectly round and so were not suitable for other settings and were going to be disposed of,” Jones says. “He was willing to donate these to my experiment.”

So what did she find? “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.

[…]

Biochemist Takeshi Furuhashi of Austria’s University of Vienna tried his own experiments with nacre shells from Red Sea oysters to see if he could reproduce Jones’s results for USA TODAY. He finds that without boiling or crushing the pearl, many hours would be needed for the acid to dissolve a large pearl. But at low concentrations of acetic acid, he reports, only an hour was required to dissolve a crushed pearl shell. So, if Cleopatra crushed the pearl, the story may be true, Furuhashi says. “However, if she put her earring directly into solution, it is impossible to obtain the same results.”

She may also have soaked the pearl in vinegar for a day or two to soften it up, he adds. Indeed, Jones says other stories about ancient wastrels knocking back pearl boilermakers involve prepared vinegar and pearl solutions being brought to the banquet table.

“I think the most likely explanations for the discrepancy between the experiment and the (legend) Pliny describes, during a banquet, are that the story compresses events for dramatic effect,” Jones says, “or that Cleopatra drank the cocktail with the pearl only partially disintegrated, having satisfied her guests that it was destroyed.”

[…]

via: Cleopatra’s pearl cocktail recipe revealed | USA Today

It’s a good article to print out for your ClassCiv classes; I’m sure you’ll all find one or more students willing to try to recreate the experiment. The abstract for the Classical World article is also online, as is Dr Jones’ abstract from a talk on the subject at the APA meeting quite a while ago should you desire to pursue this a bit further.  B.L. Ullman’s article in the 1957 Classical Journal is a good read as well …  Also of use is the Cleopatra and the Pearl page at Lacus Curtius.

More coverage:

• Scholar details legend of Cleopatra’s pearl drinking | USA Today via ABC

UPDATE: USA Today now also has a brief interview with Dr. Jones:

• Q & A: classicist Prudence Jones on Cleopatra’s pearl cocktail