Melinum, too, is a white colour, the best being the produce of the Isle of Melos.[1886] It is found also in Samos; but this last kind is never used by painters, in consequence of its being too unctuous. The persons employed in extracting it, lie at full length upon the ground, and search for the veins among the rocks. In medicine it is employed for much the same purposes as eretria;[1887] in addition to which, it dries the tongue, acts as a depilatory, and has a soothing effect. The price of it is one sestertius per pound.
The third of the white pigments is ceruse, the nature of which we have already[1888] explained when speaking of the ores of lead; there was also a native ceruse, formerly found on the lands of Theodotus at Smyrna, which the ancients made use of for painting ships. At the present day, all ceruse is prepared artificially, from lead and vinegar,[1889] as already stated.
CHAP. 20.—USTA.
Usta[1890] was accidentally discovered at a fire in the Piræus, some ceruse having been burnt in the jars there. Nicias, the artist above-mentioned,[1891] was the first to use it. At the present day, that of Asia, known also as “purpurea,” is considered the best. The price of it is six denarii per pound. It is prepared also at Rome by calcining marbled sil,[1892] and quenching it with vinegar. Without the use of usta shadows cannot be made.[1893]
CHAP. 21.—ERETRIA.
Eretria takes its name from the territory[1894] which produces it. Nicomachus[1895] and Parrhasius made use of it. In a medicinal point of view, it is cooling and emollient. In a calcined state, it promotes the cicatrization of wounds, is very useful as a desiccative, and is particularly good for pains in the head, and for the detection of internal suppurations. If the earth, when applied[1896] with water, does not dry with rapidity, the presence of purulent matter is apprehended.
CHAP. 22.—SANDARACH.
According to Juba, sandarach and ochra are both of them productions of the island of Topazus,[1897] in the Red Sea; but neither of them are imported to us from that place. The mode of preparing sandarach we have described[1898] already: there is a spurious kind also, prepared by calcining ceruse in the furnace. This substance, to be good, ought to be of a flame colour; the price of it is five asses per pound.
CHAP. 23.—SANDYX.
Calcined with an equal proportion of rubrica, sandarach forms sandyx;[1899] although I perceive that Virgil, in the following line,[1900] has taken sandyx to be a plant—