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 two with two, and three with three, proceeding in this manner to the full mixture of all the colors together: then I would begin again, mixing two of these colours with two others, and three with three, four with four, and so on to the end. To these two colours we shall put three; to these three add three more, and then six, increasing always in the same proportion.

I call those simple colours, which are not composed, and cannot be made or supplied by any mixture of other colours. Black and White are not reckoned among colours; the one is the representative of darkness, the other of light: that is, one is a simple privation of light, the other is light itself. Yet I will not omit mentioning them, because there is nothing in painting more useful and necessary; since painting is but an effect produced by lights and shadows, viz. chiaro-scuro. After Black and White come Blue and Yellow, then Green, and Tawny or Umber, and then Purple and Red. These eight colours are all that Nature produces. With these I begin my mixtures, first Black and White, Black and Yellow, Black and Red; then Yellow and Red: but I shall treat more at length of these mixtures in a separate work, which will be of great utility, nay very necessary. I shall place this subject between theory and practice. Rh