8. For example, which of the ancients can be found to have used vermilion otherwise than sparingly, like a drug? But today whole walls are commonly covered with it everywhere. Then, too, there is malachite green, purple, and Armenian blue. When these colours are laid on, they present a brilliant appearance to the eye even although they are inartistically applied, and as they are costly, they are made exceptions in contracts, to be furnished by the employer, not by the contractor.
I have now sufficiently explained all that I could suggest for the avoidance of mistakes in stucco work. Next, I shall speak of the components as they occur to me, and first I shall treat of marble, since I spoke of lime at the beginning.
CHAPTER VI
MARBLE FOR USE IN STUCCO
Marble is not produced everywhere of the same kind. In some places the lumps are found to contain transparent grains like salt, and this kind when crushed and ground is extremely serviceable in stucco work. In places where this is not found, the broken bits of marble or "chips," as they are called, which marble-workers throw down as they work, may be crushed and ground and used in stucco after being sifted. In still other places—for example, on the borderland of Magnesia and Ephesus—there are places where it can be dug out all ready to use, without the need of grinding or sifting, but as fine as any that is crushed and sifted by hand.
CHAPTER VII
NATURAL COLOURS
As for colours, some are natural products found in fixed places, and dug up there, while others are artificial compounds of different substances treated and mixed in proper proportions so as to be equally serviceable.