Magic Stones and Electric Gems Kunz: Magic of Jewels Page 67



	54 THE MAGIC OP JEWELS AND CHAEMS by Gesner as of cylindrical form, striated, and of a vitreous lustre; their color was like that of the prase and they were transparent. Although De Laet adds the assertion that the Oriental emerald (green corundum) was as hard as the sapphire, the Brazilian emeralds approached more closely to the Oriental in point of hardness than did emeralds from any other source of supply ;⁹⁴ and green sapphires have never been found in Brazil, while green tourmalines have been. The earliest published work in which the electric properties of tourmaline are noted appears to be an anonymous or quasi anonymous treatise published in 1707, certain initial letters of the quaint title being italicized to indicate the initials of the author's name.⁹⁵ The first scientist to derive the action of the so-called Aschentrekker or "Ash-Attrac-tor" from electric energy is said to have been the great Linnaeus, who bestowed upon the tourmaline the name of the "Electrical Stone.⁹⁶ The attractive properties of the tourmaline are said to have been first brought to scientific notice by M. Louis Lémery, in a report made during 1717 to the French Academy of Sciences ; however, Lémery was inclined to attribute them to magnetic influence. That these phenomena of attraction and repulsion were really due to the electric properties of the stone was first clearly brought out by the German physicist, Franz Ulrich Theodor Aepinus, and his conclusions were communicated to the Berlin Academy of Sciences in 1756.⁹⁷ Aepinus made his experiments upon two specimens of tourmaline from Ceylon, which had been "Johannis de Laet, Antwerpii, "De gemmis et lapidibus, libri duo," Lugduni Batavorum [1647], pp. 36, 40. * Curiose Speculationes bey schlaflosen Nächten . . . von einem Liebhaber der Immer Gern ßpeculirt," Chemnitz und Leipzig, bey Conr. Stosseln, 1707, 857, pp. 80. ·· Johann Gustav Donndorf, " Natur und Kunst," Leipzig, 1790, p. 5115. " " Histoire de l'Académie Royale des Sciences et Belles Lettres," toL xü, 1758; Berlin, 1758, pp. 105-121.