Cleopatra

by Stacy Schiff

Many have marveled at the tale, but only one man has sacrificed Tiffany pearls to a laboratory investigation of it. Does a pearl actually disintegrate in vinegar? Yes, if very slowly, reported B. L. Ullman, who in the end resorted to heat to nudge his 1956 experiment along: “When I boiled a pearl for 33 minutes the vinegar boiled off while I was reading a detective story. I can still smell that vinegar. The pearl seemed not to be affected, though I thought it looked a trifle peaked.” He got better results with stronger vinegar, the best results with pulverized pearl, which dissolved after three hours and twenty minutes of closely monitored boiling. This is the kind of thing to which Cleopatra has driven scholars. To the question of why Cleopatra (or anyone) might have attempted such a display in the first place—surely it made more dramatic sense to swallow the gem whole?—Ullman reminds us that pearls consist primarily of carbonate of lime, the ancient world’s bicarbonate of soda. They make an effective, if expensive, antacid.

The problem (aside from the obvious) with using pearls dissolved in vinegar as an antacid is that vinegar itself is an acid. When you dissolve the pearl in vinegar, you nullify its antacidy.