It was an ingredient in the painter’s black, called atramentum[255]. However, most of the blacks used were of the soot collected from burning various substances, such as resin, or pitch, very little different from common lamp-black, which, mixed with copperas, was mostly used for writing ink. Polygnotus and Mycon made their black of the refuse of the wine-press, burnt. Apelles used burnt ivory. Of the Indian black[256] the nature or manufacture was unknown to Pliny, as it is to us. An excellent black was procured both from the soot and ashes of torch-wood, the soot adhering to the dyers’ coppers was also sought after, and some painters imagined that the ashes from a funeral pile were preferable to all. This is properly treated by Pliny as mere superstition. When any of these blacks were used as ink, gum of some kind was added. For painting on walls size was the necessary vehicle. But vinegar was in all cases found to be the best ingredient to mix the colour properly. Dioscorides says that the soot from glass furnaces was used for ink. To these blacks, Cennino adds the burnt stones of peaches, and shells of almonds, or burnt vine twigs. They were to be mixed with various vehicles according to the work required. In India a fine black is made from burnt cocoa-nut shells. There was a colour very much used by the ancients for glazing. It was roset, or purple-red, procured by throwing Tripoli stone into the vats where fine purple dyes were boiling[257]. To make a fine red in painting, the ground was laid with sandyx[258], and then glazed with roset mixed with white of egg. When a fine purple was required the ground was laid with blue, over which the roset was applied with the same vehicle. The roset of Puteoli was reckoned the best, though finer dyes were produced by the Tyrians, Getulians, and Lacedemonians. The colour mentioned by Cennino most akin to this, is his _ametisto_, which he describes as a native mineral colour. Armenino talks of a pavonazzo still more like it in its properties. We have a purple mineral, found in the Forest of Deane, but in general our purples and purple browns are now produced from madder, or from metallic oxides. Such is the scanty information I am able to give concerning the ancient pigments, with any degree of certainty. Various earths were brought into the market from Germany and Gaul; and it is improbable that the Cologne, and other rich brown earths, should have been neglected. Cyprus appears to have furnished the painters’ shops with the greatest number and variety, both of native and manufactured colours, and no doubt the Venetians succeeded to her knowledge and skill in this matter, as they did to her commerce and maritime power[259].