Strabo is mysterious. In one place he tells us that the Cyprian copper alone produces the Cadmian stone, copperas-water, and oxide of copper. In another (lib. xiii.) he says, ‘There is a stone near Andeira which, being burnt, becomes iron. It is then put into a furnace, together with some kind of earth,[298] when it (the stone? the earth? or both?) drops or distils a ψευδάργυρος (mock silver, zinc?), which, with the addition of copper, produces what is called _the mixture_, and which some term _oreichalcum_.’ Pseudargyros, also found in the neighbourhood of Tmolus, would here seem to mean zinc or _Cadmia fossilis_ (natural calamine or carbonate of zinc). Pliny (xxxiv. 22) confuses with cadmia, furnace calamine, and a particular ore of copper opposed to calchitis. When Dioscorides (v. cap. 84) seems to allude to artificial or furnace-calamine, an impure oxide of zinc, he may mean the more modern _tutiya_ (Avicenna), _toutia_, _thouthia_,[299] _cadmie des fourneaux_, or tutty. Reduced to powder, and mixed with an equal quantity of wetted charcoal by way of fondant or flux, it is melted with copper to form brass. The Avocat de Launey (1780) and Bishop Watson both agree that Strabo’s orichalcum is brass. Lastly, aurichalcum was made synonymous with _electrum_, natural or artificial. The word Ἤλεκτρος[300] is popularly derived from Helios, as rivalling the sun in sheen. According to Lepsius it is the ‘usem’-metal of Thut-mes III.; Brugsch (i. 345) understands by ‘usem’ brass, and thinks Asmara or Asmala equivalent to the Hebrew _hasmal_ or _hashmal_ = _electrum_. In Bunsen (v. 757) Kasabet and Kakhi are brass (_aurichalcum_), and Khesbet is a metal connected with Kassiteros = tin. The alloy was known to Hesiod (‘Scut.’ 142) and to the ‘Odyssey’[301] (iv. 73), not to the ‘Iliad.’ Sophocles (‘Antig.’ 1037) applied ‘Sardian electrum’ to gold, not to silver. Herodotus (iii. 115), in the historic age (B.C. 480–30), gives the name of the mythical metal to the ‘tears of the Heliades,’ which the Latins called _succinum_ (_succum_), the Low-Latins _ambrum_, the Arabs _anbar_, and we Amber. Pliny (xxxiii. 23), repeated by Pausanias (v. 12, § 6), notes two kinds, natural (‘in all gold ore there is some silver’[302]) and artificial; in the latter the proportion of silver must not exceed one-fifth. The staters of Lydian Crœsus, held by the Greeks to be the most ancient of coins, were, according to Böckh, of electrum, three parts gold and one part silver. Lucian applies the term to glass (ὕαλος); and, lastly, it was taken for brass and confounded with aurichalcum.[303]