Wonderful things are told of the virtue of the chrysoprase, for Volmar states that, if a thief sentenced to be hanged or beheaded should place this stone in his mouth, he would immediately escape from his executioners.[69] Although we are not informed in what way this fortunate result was attained, it seems likely that the stone was believed to make the thief invisible, and thus possessed a virtue often attributed to the opal. A strange story regarding a magic stone reputed to have been worn by Alexander the Great is related by Albertus Magnus. According to this recital, Alexander, in his battles, wore a “prase” in his girdle. On his return from his Indian campaign, wishing one day to bathe in the Euphrates, he laid aside his girdle, and a serpent bit off the stone and then dropped it into the river.[70] Even Albertus, who is far from critical, admits that the story seems like a fable, and it probably belongs to a comparatively late period. As the term “prase” is used very loosely by early writers, this “victory stone” may have been an emerald or possibly jade. Coral The appreciation of coral as an ornament, or for amulets, seems to presuppose a certain development of civilization, for savage tribes greatly prefer glass ornaments. Many attempts have been made to introduce coral beads instead of glass beads among such tribes, but with no success, as the cheaper, but brighter, glass always commands a higher price.[71] To still tempests and traverse broad rivers in safety was the privilege of one who bore either red or white coral with him. That this also stanched the flow of blood from a wound, cured madness, and gave wisdom, was said to have been experimentally proved.[72] [Illustration: KABYLE JEWELRY. Of Mediterranean coral and pearls. Field Museum, Chicago.] Coral, which, for twenty centuries or more was classed among the precious stones, to retain its power as an amulet, must not have been worked, and in Italy only such pieces are valued for this purpose as have been freshly gathered from the sea or have been cast up by the sea on the shore. To exercise all its power against spells, or enchantments, coral must be worn where its brilliant color makes it conspicuous; if, however, it should by accident be broken, the separate pieces have no virtue, and the magic power ceases, as though the spirit dwelling in the coral had fled from its abode. The peasant women are careful to guard the corals they wear for a special purpose from the eyes of their husbands, for the substance is believed to grow pale at certain seasons, regaining its pristine hue after a short interval of time. Indeed, the women believe that the coral shares their indisposition with them. All this serves to show that a kind of vital force is believed to animate the material, gaining or losing in vigor according to certain conditions, and finally disappearing when the form is broken. These beliefs are all clearly traceable to the animistic ideas of primitive man.[73]