The earliest Christian painters appropriated it to painting the robes of the Virgin Mary, and called it after her name, and it is much more probable that those artists inherited the mode of preparing it, than that it was invented in the still rude times in which the arts began to revive. I saw in the middle church of the sacred convent at Assisi, a large jar which had been sent to the painters, Cimabue, Giotto, and their pupils, full of ultramarine by the Queen of Cyprus[251], for the purpose of painting that magnificent church. Some of the ancient imitations were, as I have said, composed of earth boiled with woad, those of Cennino’s time were boiled with indigo instead of woad. The blue earths from Germany appear to have been long known, indeed the cobalt, though that name had not then been given to it, was necessary for colouring the glasses and pastes used for fictitious gems by the ancient artists[252]. Indigo had been introduced into the west from India not long before Pliny’s time. Painters had, however, immediately adopted it for shadows and for strong lines. The green colours were procured in great part by the ancients as they were in the middle ages, and are now, by the mixture of blues with yellows. There were, however, several green earths in use, and many oxides of copper, sometimes used in a fluid, sometimes in a solid state. The principal green earth used by the ancients was chrysocolla, or borax. Macedonia, Armenia, and Spain, furnished the best raw material; but the best manufactory appears to have been in Cyprus. One kind of it, by boiling with dyers’ weed, assumed a golden yellow hue, and was then called orobites. The best method of using it was, to lay first a ground of the white earth, parætonum, then to wash that over with vitriol, and so lay on the chrysocolla, which is very brilliant, over that ground. The green made from orobites mixed with azure is not durable, though bright[253]. The borax is, doubtless, the terra verde of Cennino, the terre verte of the moderns; the best is now procured from Holland, where the art of preparing it is understood. For some ages this art was in the hands of the Venetians, who imported the borax from India, Persia, and China, where it is produced at the bottom of some lakes. It is also found in similar situations in Tuscany[254]. But verdigris, variously prepared, was used both by painters and the manufacturers of glass for ornamental purposes, as well as by surgeons and physicians for potions and plasters among the ancients. In Giotto’s time, it entered into the composition of many tints, several of which, however, faded easily. With the moderns it is not much used, as being apt to disagree with some other pigments, and difficult of application.