Commentary Page 167



	THEOPHRASTUS ON STONES

	of the metal in the De Mirabilibus Auscultationibus. This word may easily be translated "very white" instead of "very pale" or "very light in color," and if the word is so understood, then the metal could not have been brass. However, it could have been a copper-arsenic alloy, since such alloys, even when they contain a relatively small proportion of arsenic, are white in color, not yellow like brass or bronze. Alloys of copper and arsenic were known in the Aegean region from very early times, as has been shown by chemical analyses.³⁵⁸ Moreover, two recipes in the Leyden Papyrus X give methods of whitening copper by treating the metal with arsenic minerals or with products derived from such minerals. One of these recipes (No. 23) reads as follows: WHITENING OF COPPER To whiten copper, so that it can be mixed with silver bullion in equal parts, and not be recognized: take Cyprian copper, melt it, add one mina of decomposed realgar, two drachmas of ironlike realgar, and five drachmas of lamellose alum, and melt (again). In the second fusion four drachmas, or less, of Pontic wax are added, and the mixture is ignited and poured out.³⁵⁹ Probably the decomposed realgar mentioned in this recipe was, at least in part, arsenious oxide prepared by roasting the mineral, and the iron-like realgar may have been native arsenic. The wax · served both to reduce arsenic compounds, so that the arsenic would alloy with the copper, and to prevent the oxidation of copper and arsenic during melting and casting. It may be of some significance that the wax is described as Pontic, since the account in the De Mirabilibus Auscultationibus refers to the manufacture of "whitened" copper by people living in one part of Pontus. This suggests that the account refers to the manufacture of a copper-arsenic alloy, not brass. Since this passage in Theophrastus is similar to the one in the De Mirabilibus Auscultationibus, it might be argued that it also refers to the manufacture of a copper-arsenic alloy. However, the two passages are not so much alike that this conclusion is entirely logical. Theophrastus actually says nothing about whitening the ³⁵⁸ E. R. Caley, Hesperia, Supplement VIII (1949), 60-63. ³⁵⁹ Translated from the text of Berthelot, Archeologie et Histoire des Sciences, p. 278.

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