Thus much then with reference to the dignity of this now expiring art. We have already[1] stated with what single colours the earlier artists painted, when speaking of these pigments under the head of metals. The new modes of painting which were afterwards discovered, and are known as "neogrammatea,"[2] the names of the artists, their different inventions, and the periods at which these inventions were adopted, will all be described when we come to enumerate the painters: for the present, however, the proposed plan of this work requires, that I should enlarge upon the nature of the several colours that are employed.

The art of painting at last became developed, in the inven- tion of light and shade, the alternating contrast of the colours serving to heighten the effect of each. At a later period, again, lustre[3] was added, a thing altogether different from light. The gradation between lustre and light on the one hand and shade on the other, was called "tonos;" while the blending of the various tints, and their passing into one another, was known as "harmoge."[4]