He found that, upon holding tightly in the hand a large bar of amber and rubbing it briskly against woollen cloths, “a prodigious number of little cracklings was heard, every one of which produced a small flash of light (spark); and that when the amber was drawn lightly through the cloth it produced a spark but no crackling.” He observed that “by holding a finger at a little distance from the amber a crackling is produced, with a great flash of light succeeding it, and, what is very surprising, on its eruption it strikes the finger very sensibly, wheresoever applied, with a push or puff like wind. The crackling is fully as loud as that of charcoal on fire.... This light and crackling seem in some degree to represent thunder and lightning.” REFERENCES.--Bakewell, “Electric Science,” p. 13; Aglave et Boulard, “Lumière Electrique,” 1882, p. 17; Thos. Thomson, “An Outline of the Sciences of Heat and Electricity,” London, 1830, pp. 314, 463; Thos. Thomson, “Hist. of the Roy. Soc.,” London, 1812, p. 431; see also the following abridgments of the _Phil. Trans._; Hutton, Vol. V. p. 408 and Baddam of 1745, Vol. V. p. 111. =A.D. 1712.=--The great Japanese Encyclopædia, _Wa-Kan-san siü tson-ye_, describes the compass, _zi-siak-no-fari_, at Vol. XV. folio 3, _recto_ (Klaproth, “Lettre à M. de Humboldt,” etc., 1834, p. 107). =A.D. 1717.=--Leméry (Louis), two years after the death of his distinguished father, Nicolas Leméry, exhibits a stone (the _tourmaline_) brought from Ceylon, and announces, to the French Académie des Sciences, that it possesses the electrical property of attracting and repelling light bodies after being warmed. Carl Linnæus (1707–1777) alludes to the experiments of Leméry, in his _Flora Zeylanica_, and mentions the stone under the name of _lapis electricus_. (See, for Carl Linnæus, “Thesaurus Litteraturæ Botanicæ,” G. A. Pritzel, Lipsiæ, 1851, pp. 162–169, also “Guide to the Literature of Botany,” by Benj. Daydon Jackson, London, 1881, pp. xxxvi, etc.) The first scientific examination of the electric properties of the tourmaline was, however, made by Æpinus in 1756, and published in the Memoirs of the Berlin Academy. Æpinus showed that a temperature of between 99½° and 212° F. was necessary for the development of its attractive powers. Of the electricity of crystals, Gmelin, in his “Chemistry” (Vol. I. p. 319), names the following discoverers: Æpinus (tourmaline)--see A.D. 1759; Canton (topaz)--see A.D. 1753; Brard (axinite)--see A.D. 1787; Haüy (boracite, prehnite, sphene, etc.)--see A.D. 1787; Sir David Brewster (diamond, garnet, amethyst, etc.)--see A.D. 1820; and Wilhelm Gottlieb Hankel (borate of magnesia, tartrate of potash, etc.). REFERENCES.--Becquerel, “Résumé,” 1858, p. 11; Leithead, “Electricity,” p. 239; “Ph. Hist. and Mem. of Roy. Ac. of Sc. at Paris,” London, 1742, Vol. V. p. 216; “Journal des Sçavans,” Vol. LXX for 1721, pp. 572–573 on the tourmaline.