1. We shall first set forth the natural colours that are dug up as such, like yellow ochre, which is termed w)/xra in Greek. This is found in many places, including Italy, but Attic, which was the best, is not now to be had because in the times when there were slaves in the Athenian silver mines, they would dig galleries underground in order to find the silver. Whenever a vein of ochre was found there, they would follow it up like silver, and so the ancients had a fine supply of it to use in the polished finishings of their stucco work.