The material called “St. Paul’s Earth,” said to be derived from “St. Paul’s Cave,” in the island of Malta, was reduced to a fine powder and made into tablets. These were stamped with the Maltese cross; sometimes on the opposite side some other figure was impressed. As there was temptation to sell other material for the genuine, the purchaser was warned to be on his guard. The virtues of this powder—which was dissolved in wine or water—were numerous, and were the same as those ascribed to the “tongues” (_glossopetræ_) and to the “eyes”; for it was believed to be an antidote for poisons, cured the bites of venomous creatures, and remedied many other ills. The “eyes” were set in rings so that the material touched the wearer’s skin; the “tongues” were worn attached to the arm or suspended from the neck. Sometimes vessels were made from the earth. These were filled with wine or water, the liquid being allowed to stand until it had absorbed the virtues of the earth; it was then taken as a potion with good effects. The “tongues” and “eyes” were often dipped in wine or water and were supposed to transmit their curative powers to the liquid.[392] In the fifteenth and sixteenth centuries a strange belief was prevalent among the ignorant to the effect that the fossil sharks’-teeth, the “tongue-stones,” were the teeth of witches who sucked the blood of infants; these “vampires” were called _lamiæ_ in ancient times.[393] Probably the fact that a certain species of shark bore the name _lamiæ_ gave rise to this idea, which was therefore merely due to a confusion of names. Nevertheless we can easily understand that this popular belief added to the repute of the _glossopetræ_, for the more dreaded the object the greater the power it was credited with possessing. In the seventeenth century De Laet (d. 1649), the Dutch naturalist and geographer, received in Leyden certain _glossopetræ_ sent him by a friend in Bordeaux, who wrote that they would cure any one suffering from soreness of the mouth, whether this were the result of having eaten impure food, or were produced by some derangement of the secretions. The “tongues” were to be dipped in spring water and would cause bubbles to form therein; as soon as these disappeared, the water was to be used as a gargle, and the mouth was to be washed with it two or three times. De Laet’s friend assured him that this treatment would cure the disorder in twenty-four hours.[394] A seventeenth century amulet of a fossil shark’s tooth, mounted in silver and found in an excavation at Salzburg, Austria, was among the objects exhibited by the writer for the New York branch of the American Folk-Lore Society, in the Department of Ethnology of the Columbian Exposition held in Chicago, in 1893. They are frequently found at Lake Constance but are from the ancient fossiliferous formations and not from the lake. They are often sold as amulets. [Illustration: