Naturalis historia 34.163

34.163

coepere deinde et esseda sua colisataque ac petorita exornare simili modo, quae iam luxuria ad aurea quoque, non modo argentea, staticula pervenit, quaeque in scyphis cerni prodigum erat, haec in vehiculis adteri cultus vocatur. plumbi albi experimentum in charta est, ut liquefactum pondere videatur, non calore, rupisse. India neque aes neque plumbum habet gemmisque ac margaritis suis haec permutat.

CHAP. 48. (17.)—STANNUM. ARGENTARIUM. When copper vessels are coated with stannum, they produce a less disagreeable flavour, and the formation of verdigris is prevented; it is also remarkable, that the weight of the vessel is not increased. As already mentioned, the finest mirrors were formerly prepared from it at Brundisium, until everybody, our maid-servants even, began to use silver ones. At the present day a counterfeit stannum is made, by adding one-third of white copper to two-thirds of white lead. It is also counterfeited in another way, by mixing together equal parts of white lead and black lead; this last being what is called "argentarium." There is also a composition called "tertiarium," a mixture of two parts of black lead and one of white: its price is twenty denarii per pound, and it is used for soldering pipes. Persons still more dishonest mix together equal parts of tertiarium and white lead, and, calling the compound "argentarium," coat articles with it melted. This last sells at sixty denarii per ten pounds, the price of the pure unmixed white lead being eighty denarii, and of the black seven.
White lead is naturally more dry; while the black, on the contrary, is always moist; consequently the white, without being mixed with another metal, is of no use for anything. Silver too, cannot be soldered with it, because the silver becomes fused before the white lead. It is confidently stated, also, that if too small a proportion of black lead is mixed with the white, this last will corrode the silver. It was in the Gallic provinces that the method was discovered of coating articles of copper with white lead, so as to be scarcely distinguishable from silver: articles thus plated are known as "incoctilia." At a later period, the people of the town of Alesia began to use a similar process for plating articles with silver, more particularly ornaments for horses, beasts of burden, and yokes of oxen: the merit, however, of this invention belongs to the Bituriges. After this, they began to ornament their esseda, colisata, and petorita in a similar manner; and luxury has at last arrived at such a pitch, that not only are their decorations made of silver, but of gold even, and what was formerly a marvel to behold on a cup, is now subjected to the wear and tear of a carriage, and this in obedience to what they call fashion!
White lead is tested, by pouring it, melted, upon paper, which ought to have the appearance of being torn rather by the weight than by the heat of the metal. India has neither copper nor lead, but she procures them in exchange for her precious stones and pearls.