REFERENCES.--“Greek Thinkers,” by Theodor Gomperz, translation of L. Magnus, London 1901, p. 532; Zahn at A.D. 1696; Joannes Ruellius, “De Natura Stirpium,” 1536, p. 125; Paul Tannery, “Pour l’Histoire de la Science Hellène,” Paris, 1887, chap. iii. pp. 52–80; Becquerel, “Traité Expérimental,” Paris, 1834, Vol. I. p. 33; Pliny, “Natural History,” Bostock and Riley, 1858, book 37, chap. xii. p. 403; Pline, “Histoire Naturelle,” 1778, livre 37, chapitre iii.; Lardner, “Lectures,” 1859, Vol. I. p. 104; Humboldt, “Cosmos,” 1849, Vol. I. p. 182; Poggendorff, XI. p. 1088; Apuleius, Floridor, p. 361; Plato; Timæus, The Locrian; “De Anima Mundi ...,” 12, 15; Pauli (Adrian), Dantzig, 1614; Ulysses Aldrovandus, “Musaeum Metallicum,” pp. 411–412; Aurifabrum (Andreas), “Succini Historia,” ... Königsberg, 1551–1561; and, for the different names given to amber and the magnet by the ancients, consult, more especially, the numerous authorities cited by M. Th. Henri Martin (“Mém. présenté à l’Académie des Inscrip. et Belles Lettres,” première partie, Vol. VI. pp. 297–329, 391–411, Paris, 1860); J. Matthias Gessner, “De Electro Veterum” (Com. Soc. Reg. Sc. Gött., Vol. III for 1753, p. 67); Louis Delaunay, “Minér. des Anciens,” Part 2, p. 125 (Poggendorff, Vol. II. p. 540); Philip Jacob Hartmann, in _Phil. Trans._, Vol. XXI. No. 248, pp. 5, 49, also in Baddam’s Abridgments, Vol. III, first edition, 1739, pp. 322–366. =B.C. 600.=--The Etruscans are known to have devoted themselves at this period to the study of electricity in an especial manner.[4] They are said to have attracted lightning by shooting arrows of metal into clouds which threatened thunder. Pliny even asserts that they had a secret method of not only “drawing it (the lightning) down” from the clouds, but of afterwards “turning it aside” in any desired direction. They recognized different sources of lightning, those coming from the sky (_a sideribus venientia_), which always struck obliquely, and others from the earth (_infera_, _terrena_), which rose perpendicularly. The Romans, on the other hand, recognized only two sorts, those of the day, attributed to Jupiter, and those of the night, attributed to Summanus (see Vassalli-Eandi at A.D. 1790). This Vassalli-Eandi--like L. Fromondi--made special study of the very extensive scientific knowledge displayed by the ancients and, as shown in his “Conghietture ...” he concluded that they really possessed the secret of attracting and directing lightning. The above-named extracts concerning the Etruscans and Romans are made from the subjoined work of Mme. Blavatsky, wherein the following is likewise given.