CHAP. 48. (17.)—STANNUM. ARGENTARIUM.

When copper vessels are coated with stannum,[1] 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,[2] 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.[3] 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."[4] 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[5] 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.[6]

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[7] 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."[8] At a later period, the people of the town of Alesia[9] 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.[10] After this, they began to ornament their esseda, colisata, and petorita[11] 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,[12] 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,[13] but she procures them in exchange for her precious stones and pearls.

1. A compound metal, probably, somewhat like pewter. See Note 95 above. He evidently alludes to the process of "tinning."

2. In B. xxxiii. c. 45: where he says that the best mirrors were formerly made of a mixture of stannum and copper.—B. See Beckmann, Hist. Inv. Vol. II. pp. 60–62, 72.

3. Or tin.

4. "Silver mixture."

5. Such a mixture as this would in reality become more valuable than "argentarium," as the proportion would be two-thirds of tin and one of lead. How then could the workmen merit the title of dishonest? Beckmann suggests that the tinning ought to have been done with pure tin, but that unprincipled artists employed tin mixed with lead. It is most probable, however, that Pliny himself has made a mistake, and that we should read "equal parts of black lead" (our lead); in which case the mixture passed off as "argentarium," instead of containing equal parts of tin and lead, would contain five-sixths of lead. See Beckmann, Hist. Inv. Vol. II. p. 221. Bohn's Edition.

6. All these readings are doubtful in the extreme.

7. As being too brittle, probably; the reason suggested by Beckmann, Vol. II. p. 221.

8. Literally, "inboiled," being coated by immersion in the molten tin.

9. Supposed by Hardouin to have been the town of Alise, in Auxois.

10. See B. iv. c. 33.

11. The names of various kinds of carriages, the form of which is now unknown.

12. Both tin and lead can be fused in paper, when it is closely wrapped around them.

13. In reality India did and does possess them both; but it is possible that in those days it was not considered worth while to search for them.