Cochineal, which was first brought from America in the sixteenth century, has now replaced almost every other scarlet dye for textiles.
Crimson is once mentioned in Chronicles as karmel,[301] which may mean the dye of the kermes insect;[302] and from this the word crimson is legitimately derived. Whether the scarlet coupled with it is a vegetable, mineral, or insect colour, we have no means of ascertaining. “Though your sins be as scarlet, they shall be as white as snow; though they be red as crimson, they shall be as wool.”[303]
From what Pliny says, it appears that some green dyes were produced from a green clay; others from metals. Copper furnished the most beautiful shades.
Blue has always been extracted from indigo. Pliny tells us that the Phœnicians brought it from Barbarike, in the Indies, to Egypt; and he quotes the “Periplus” on this subject. He gives an amusing report that indigo is a froth collected round the stems of certain reeds; but he was aware of its characteristic property, that of emitting a beautiful purple vapour when submitted to great heat; and he says it smells like the sea. The Egyptians likewise extracted blues from copper.
Yellow was anciently, in Egypt, sometimes a vegetable and sometimes a mineral dye. Browns and blacks were prepared from several substances, especially pine wood and the contents of tombs burned into a kind of charcoal.
We find that lime, chalk, white lead, and other mineral substances were employed by the ancients for the different approaches to dazzling whiteness. That of the lily, the emblem of purity, can only be emulated in textile or pictorial art by opaque substances reduced as much as possible by bleaching to the last expression of the colour of the raw material. Nothing that is transparent can be really white, as colours are seen through it, as well as the reflected lights on the two surfaces.
In painting, we can produce the effect of whiteness in different ways, leading by the gradation of tender colours and shadows up to a high light. But in textile art, which is essentially flat, it is necessary to pursue a different method, and that of isolation is the most simple and effective, and was well understood in Egypt, Greece, and India. The white pattern, or flower, is surrounded with a fine dark line (black is the best), which effectually separates it from all the surrounding colours, and gives it the effect of light, even when the whiteness retains enough of the natural colour of the raw material to tone it down very perceptibly. The eye accepts it as white, and ignores the tint that pervades it, and is hardly to be expelled from silk or wool. Linen and cotton are the whitest of materials, after passing through the hands of the chemist or the bleacher.
It is amusing to observe that Pliny regarded colours, whether vegetable or mineral, rather as useful for the pharmacopeia of his day, than as dyes or artistic pigments. He speaks contemptuously of the art of his time, and yet he gives some curious hints that are well worth collecting for experiment. His fragmentary information, though often inaccurate, is most valuable to those who are seeking once more to find lasting colours, and despair of discovering mordants that will fix the aniline tints. From him we learn more of the Egyptian colouring materials than of any others, as he named their sources, European, Asiatic, or African; and there is no doubt of the perfection of their mural pigments and textile dyes, which have remained unimpaired to the present time.
Renouf says that “painting, as it is now understood, was totally unknown to the Egyptians; but they understood harmony of colour,[304] and formulated in it certain principles for decorative uses. They made the primary colours predominate over the secondary by quantity and position. They introduced fillets of white or yellow in their embroideries, as well as in their paintings, between reds and greens, to isolate them; and they balanced masses of yellow with a due proportion of black.” They never blended their colours, and had no sense of the harmony of prismatic gradations, or the melting of one tint into another; each was worked up to a hard and fast edge line. If in one part of a building, one set of colours predominated, they placed a greater proportion of other colours elsewhere, within the range of sight, so as to readjust the balance. Those they employed were mostly earthy mineral colours (used alike for frescoes and for painting cotton cloths, though vegetable dyes were needed for woollens and linens). These were: for white, pure chalk; for black, bone-black mixed with gum; for yellow, yellow ochre; for green, a mixture of yellow ochre and powdered blue glass; for blue, this same blue glass mixed with white chalk; for red, an earthy pigment containing iron and aluminium.[305] They understood the chemistry of bleaching, and the use of mordants in dyeing.[306]
The statistical records of China of the time of Hias (2205 B.C.), according to Semper, mention colours as being of five tints, and all the produce of the Chinese Empire.[307]