[ 189 ]
LXXIX. It is ſaid alſo, that there is a much better Kind of this Stone now found out, than that which was formerly uſed; inſomuch, that it now ſerves not only for the Trial of the refined Gold, but alſo of Copper or Silver coloured with Gold; and ſhews how much of the adulterating Matter by Weight is mixed with Gold: This has Signs which it yields from the ſmalleſt Weight of the adulterating Matter, which is a Grain, from thence a Colybus, and thence a Quadrans or Semi-Obolus; by which it is eaſy to diſtinguiſh if, and in what Degree, that Metal is adulterated.
Theophraſtus: nunc vero paſſim, quem alii Heraclium, alii Lydium vocant. On which Salmaſius's Remark is this, Fallitur Plinius peccatque non mediocriter. Lapis hic Lydius quo aurum & argentum probatur, nunquam dictus eſt Heraclius, ſed ille alter Lydius qui ferrum rapit. I am ſorry to ſay it, but it is fallitur Salmaſius, not Plinius; for we need look no farther than this Author to know, that Heraclius was as common a Name for the Touchſtone among the Antients, as for the Loadſtone: See p. 24, where he expreſsly ſays, that the Touchſtone was ſo called, οἱ δὲ βασανίζειν τὸν ἄργυρον ὥσπερ ἥτε καλȣμένη λίθος Ἡράκλεια καὶ ἡ Λυδη. The Loadſtone and Touchſtone were therefore both called among the Antients, from their common Country, Lapis Lydius, and Lapis Heraclius. And for that Reaſon there have been great Errors in regard to them, in many of the leſs careful Writers ſince: As about the two Cyanus's, and, in ſhort, all the Subſtances which they had thus confuſed, in not allowing them particular Names. It has ſince, been called Lapis Baſanites, from its Uſe in trying
