Note 970 — BOOK XXXIII. THE NATURAL HISTORY OF METALS.647

See the description of the mode of gilding, given in Chapter 20 of this Book. Beckmann has the following remarks on the present passage: “That gold-leaf was affixed to metals by means of quicksilver, with the assistance of heat, in the time of Pliny, we are told by himself in more passages than one. The metal to be gilded was prepared by salts of every kind, and rubbed with pumice-stone in order to clean it thoroughly (see Chapter 20), and to render the surface a little rough. This process is similar to that used at present for gilding with amalgam, by means of heat, especially as amalgamation was known to the ancients. But, to speak the truth, Pliny says nothing of heating the metal after the gold is applied, or of evaporating the quicksilver, but of drying the cleaned metal before the gold is laid on. Had he not mentioned quicksilver, his gilding might have been considered as that with gold leaf by means of heat, dorure en feuille à feu, in which the gold is laid upon the metal after it has been cleaned and heated, and strongly rubbed with blood-stone, or polished steel. Felibien (Principes de l’Architecture. Paris, 1676, p. 280) was undoubtedly right when he regretted that the process of the ancients, the excellence of which is proved by remains of antiquity, has been lost.”—Hist. Inv. Vol. II. pp. 294, 295. Bohn’s Edition.