How Cleopatra won her bet

Cleopatra, the last queen of Egypt,
might have indeed drunk a pearl cocktail in a gulp, an experimental study has

Legend has it that, in order to
show her wealth and power, Cleopatra VII (69 B.C. – 30 B.C.) made a bet with
her lover — the Roman leader Marc Antony — that she could spend 10 million
sesterces on one meal.

“She ordered the second course
to be served. In accordance with previous instructions, the servants placed in
front of her only a single vessel containing vinegar. … She took one earring
off, and dropped the pearl in the vinegar, and when it was wasted away,
swallowed it,” Roman naturalist and philosopher Pliny the Elder (23 – 79
A.D.) wrote in his Natural

Indeed, the pearl was not just any
pearl. Pliny called it “the largest in the whole of history,” a
“remarkable and truly unique work of nature” worth 10 million

Although the account was considered
credible in antiquity, modern scholars have dismissed the story as fiction.

Giving ancient sources the benefit
of the doubt, classicist Prudence Jones of Montclair State University in New
Jersey experimented with vinegar and a five-carat pearl to find out whether the
acetic acid concentration is sufficient to dissolve calcium carbonate.

“All you need is vinegar and a
pearl. In my experiments, I used white vinegar sold in supermarkets. Wine
vinegar was most common in the Greco-Roman world, so it is likely that’s what
Cleopatra used,” Jones said.

Jones found that a 5 per cent
solution of acetic acid, a concentration identical to that of white vinegar
sold in supermarkets today, takes 24 to 36 hours to dissolve a pearl weighing approximately
one gram. The process leaves a small amount of translucent, gel-like material
on the surface.

The cocktail would have been less
appetizing than a martini with the traditional olive, but still palatable.

“The calcium carbonate in the
pearl neutralizes some of the acid, so the resulting drink is not as acidic as
vinegar,” said Jones.