A thing that is not the case with any other metal, gold is found pure in masses[858] or in the form of dust;[859] and whereas all other metals, when found in the ore, require to be brought to perfection by the aid of fire, this gold that I am speaking of is gold the moment it is found, and has all its component parts already in a state of perfection. This, however, is only such gold as is found in the native state, the other kinds that we shall have to speak of, being refined by art. And then, more than anything else, gold is subject to no rust, no verdigris,[860] no emanation whatever from it, either to alter its quality or to lessen its weight. In addition to this, gold steadily resists the corrosive action of salt and vinegar,[861] things which obtain the mastery over all other substances: it admits, too, beyond all other metals, of being spun out and woven[862] like wool.[863] Verrius tells us that Tarquinius Priscus celebrated a triumph, clad in a tunic of gold; and I myself have seen Agrippina, the wife of the Emperor Claudius, on the occasion of a naval combat which he exhibited, seated by him, attired in a military scarf[864] made entirely of woven gold without any other material. For this long time past, gold has been interwoven in the Attalic[865] textures, an invention of the kings of Asia. CHAP. 20.—THE METHOD OF GILDING. On marble and other substances which do not admit of being brought to a white heat, gilt is laid with glair of egg, and on wood by the aid of a glutinous composition,[866] known as “leucophoron:” what this last is, and how it is prepared, we shall state on the appropriate occasion.[867] The most convenient method for gilding copper would be to employ quicksilver, or, at all events, hydrargyros;[868] but with reference to these substances, as we shall have occasion to say when describing the nature[869] of them, methods of adulteration have been devised. To effect this mode of gilding, the copper is first well hammered, after which it is subjected to the action of fire, and then cooled with a mixture of salt, vinegar, and alum.[870] It is then cleansed of all extraneous substances, it being known by its brightness when it has been sufficiently purified. This done, it is again heated by fire, in order to enable it, when thus prepared, with the aid of an amalgam of pumice, alum, and quicksilver, to receive the gold leaf when applied. Alum has the same property of purifying copper, that we have already[871] mentioned us belonging to lead with reference to gold. CHAP. 21. (4.)—HOW GOLD IS FOUND.