“There were two pearls, the largest that had been ever seen. Cleopatra was in possession of them both. When Antony had been sated by her, she made a wager that on a single entertainment she would expend ten millions of sesterces.
On the following day, upon which the matter was to be decided, she had an entertainment set before Antony, magnificent in every respect. In obedience to her instructions, the servants placed before her a single vessel, which was filled with vinegar.
At this moment she was wearing in her ears those choicest and most rare and unique pearls; and taking one of them from out of her ear, she threw it into the vinegar, and directly it was melted, and drank it.”
Pliny, Natural History, 9.58
