Note 757 — ARTIFICIAL PEARLS.

It was because pearls are calcareous that Cleopatra was able to dissolve hers in vinegar, and by these means to gain a bet from her lover, as we are told by Pliny, 1. ix. c. 35, and Macrobius Saturn. 1. ii. c. 13. She must, however, have employed stronger vinegar than that which we use for our tables, as 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 effects of acids, by an enamel covering which answers the same purpose; 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 dissolved calcareous matter neutralizes acids and renders them imperceptible to the tongue. We are told that the dissipated Clodius gave to each of his guests a pearl dissolved in vinegar to drink:—“Ut experiretur in gloria palati,” says Pliny, “quid saperent margaritæ; atque ut mire placuere, ne solus hoc sciret, singulos uniones convivis absorbendos dedit.” Horace, lib. ii. sat. 3, says the same. That pearls are soluble in vinegar is remarked in Pausanias, b. viii. ch. 18, and Vitruvius, b. viii. ch. 3.