The metallic electrum was an alloy of gold with about twenty per cent. of silver. It occurs naturally, but was produced artificially as well, especially in Egypt, where _asem_, as it was called, came into favour long before any of the pyramids were built. It was in the Nile valley thought fit for goddesses’ wear, its pale radiance suggesting feminine refinement; and stores of it were laid up in the treasures of all the early kings. The first Lydian coinage was of electrum; many of the utensils and ornaments discovered at Hissarlik and Mycenæ prove to be similarly composed; and electrum continued in favour down to a particularly late date in the Græco-Scythic settlements on the Black Sea. It made one of its few historical appearances in the ‘white gold’ offered by Crœsus at Delphi;[327] and there are two instances of its epical employment. The ground of the Hesiodic Shield of Hercules was inlaid, the walls of the banqueting-hall of Menelaus were overlaid, with gold, electrum, and ivory. Although, in two other passages of the Odyssey, the same word undoubtedly designates amber, it is safe to affirm that here, where mural incrustations are in question, a metallic substance, none other than the immemorial _asem_ of Egypt, should be understood. Egyptian analogies, as Lepsius many years ago pointed out, strongly support this supposition, above all where Egyptian associations are so marked as in the Odyssean description of the Spartan court. Electrum is unknown in the Iliad. The word occurs only in the form _elektor_, signifying ‘the beaming sun.’ Footnote 327: Herodotus, i. 50. The third Homeric metal, and the most important of all, is _chalkos_. But what does _chalkos_ mean? Copper or bronze? The question is not one to be answered off-hand or categorically. It has been long and learnedly debated; and admits, perhaps, of no decision more absolute than the cautious arbitrament of Sir Roger de Coverley.