THE DYES OF OUR ANCESTORS
Between the days of the ancient Greeks and Romans, and the discovery of the first aniline dye in 1856, many and important additions were made to the list of available dyestuffs, some of which have continued in use, for special purposes, up to the present day.
Indian Dyes.—The opening of trade to the Far East, due to the discovery of the sea route round the Cape of Good Hope, brought to Europe the free use of some of the Indian dyestuffs. Indigo, for instance, was introduced for the first time in considerable quantities, and, after much opposition, completely took the place of the much inferior native dyestuff, woad.
For yellow, the old saffron dye was superseded by the more powerful, but still rather fugitive, turmeric, or Indian saffron. This came from the root of the curcuma tinctoria, a plant freely grown to this day in both India and China. The safflower was also imported from India; this is a kind of thistle,carthamus tinctorum, the dried heads of flowers of which were largely used for dyeing pretty shades of pink upon cotton,directly—that is, without any mordanting process. This color, too, is comparatively fugitive to light, and has almost disappeared from sight.
Of more importance were the so-called red woods, which came partly from India and partly from the east and west coasts of Africa; and of which the most important are the sandal wood, bar wood, and cam wood. The wood of each of these trees probably contains the same coloring matter. The color is not very easy to extract, but when used with mordants of chromium, aluminium, or tin salts, it dyes wool various shades of red and reddish-brown. These colors are very fast to milling—in other words to the action of alkalies when the wool is finished in the manufacture of broadcloth; but they are not particularly fast to light, and for this reason, as well as because of their greater expense, they have been for the most part abandoned.
From India, too, were introduced the well-known brown dyes known as cutch (catechu) and gambier. These come to the market in the form of dark colored pastes, formed by evaporating infusions of leaves, seed pods, nuts, and sometimes the wood of various species of acacia and areca trees. They contain large amounts of a peculiar variety of the substance known as tannin or tannic acid, which is widely distributed among many plants, and which is very useful in dyeing, as will be described later. The brown coloring matter has been isolated, and is called catechin. Both cutch and gambier will dye cotton and wool rich shades of brown, which are quite fast to light when after-treated with copper or chromium salts.
Dyes from the New World.—The discovery of America, and the colonizing and opening to trade of South America and the West Indies, in the sixteenth and seventeenth centuries, still further enlarged the field for dyers.
Cochineal.—One of the first dyes introduced from there was cochineal, a “grain color,” similar to kermes, already described, consisting of the dried bodies of an insect known ascoccus cacti, because it lives upon certain kind of cactus which are native to Mexico and Central America.
This dyestuff was largely used for dyeing wool and silk goods, and produced fairly fast shades of crimson or of scarlet, according to the mordant employed. But it has been replaced almost entirely now by the various acid dyes, to be described later, which are cheaper, are much easier to apply, and are of equal and, in many cases, of much greater, fastness to light.
One of the few cases where cochineal is still used on a large scale is in England, where the scarlet coats of the British regulars are dyed with this color, on a tin mordant. It is believed, however, that this is not due to any real or fancied superiority of the old dye over many of the modern colors, but simply to the terms of an old “perpetual” contract, which, a hundred and fifty years or more ago, gave the privilege of dyeing the English “redcoats” to one particular firm and their successors, on condition that they use this dye and none other. Although both dyers and government would profit by the use of modern dyes, the terms of the old contract are still rigidly adhered to for fear of losing the monopoly.
Lac Dye.—The similar dyestuff called lac dye, which had been known and used in India for hundreds of years, was introduced into Europe towards the end of the eighteenth century. It also is the body of a small insect, thecoccus laccae, which lives on the twigs of the banyan tree, and other varieties of fig trees. When these twigs are broken off and dried to kill the insect, there is found present on them, along with the coloring matter, a large amount of a peculiar resinous or gummy substance, which, when extracted and purified, is known and widely used, as “shellac.”
Lac dye was used in practically the same way as cochineal, and produced, upon wool, scarlet, orange, and crimson shades, which were faster and more solid, but not as brilliant, as the cochineal. It is now used but rarely, even in the East, having been largely superseded, there, by brilliant but, unfortunately, in many cases, cheap and worthless modern dyestuffs.
Fustic.—From America, also, came the excellent yellow dyestuff, “fustic,” yielded by the tree commonly called yellow wood, Cuba wood, etc. Its true botanical name, however, ischlorophora tinctoria, and it was largely used for dyeing, either directly in the form of chips, or as a solid or liquid extract made from the wood.
It was principally used with mordants of aluminium or tin salts, for dyeing wool bright, fast shades of yellow, or, with the aid of bichromate of potash as a mordant, for obtaining mixed shades, in conjunction with indigo, cutch, madder, and logwood. It has been almost entirely replaced now by fast modern dyestuffs.
Logwood.—The most important of all these dyestuffs, and the only one still used on a large scale, is logwood, a dye extracted from the wood of quite a large tree, thehaematoxylon Campechianum (the “blood-red wood from Campeachy”), which grows freely in the West Indies and Central American states.
It was discovered and used by the Spaniards early in the sixteenth century, and in Queen Elizabeth’s reign was introduced into England, much against the wishes of the older school of dyers who furiously denounced it as producing fugitive colors, and had its use prohibited by Act of Parliament. It was over a hundred years before the real value of the dyestuff was appreciated, and this law was repealed.
The operation of extracting the coloring matter from the wood itself, of which it forms only some three per cent. by weight, is a troublesome and delicate one. The logs are chipped or rasped into fine pieces, then moistened and piled in heaps and the color developed by a process of fermentation. Accordingly, extracts of logwood have been put on the market by various large firms, especially of late years, and, while the use of the wood itself by dyers has for the most part been abandoned, these extracts are widely used for dyeing blacks upon silk, in spite of there now being many excellent acid blacks.
The dyeing process, too, is rather complicated, for the goods must be carefully mordanted before dyeing, with salts of iron, chromium, or tin. For this reason wool is rarely dyed with logwood. It is, however, still used for silk dyeing, partly because it gives very full, deep, permanent shades of black, but principally because, by using one mordant after another before dyeing, it is possible to increase enormously the weight of the dyed silk, at very moderate expense.
Turkey Red.—The use of madder which, as before mentioned, was probably known to the ancients, was greatly developed during the sixteenth and seventeenth centuries, owing to the introduction from the near East of the so-called Turkey red process for obtaining, upon cotton and wool, very fast and very brilliant shades of scarlet.
The process took some three months, and consisted of an elaborate series of mordanting operations, before the dyeing proper began. The goods were first soaked in a bath of some fatty material, such as milk or, later, rancid olive oil, and then dried carefully. After this they were soaked in a bath of alum and then in limewater, or a chalk bath—and these operations were repeated over and over, with various manipulations in between.
Finally, the mordanted material was dyed by boiling it in a bath containing the finely-ground madder root, and then “brightened” by washing out, in a boiling soap bath, all the loose color and the unfixed mordant. This process was repeated until the proper shade was reached.
During the early part of the nineteenth century, various extracts of madder were made, by treating the ground root with strong sulphuric acid and other agents, which destroyed the woody tissues and other inert matter, without injuring the coloring matter. The dyeing process also was greatly simplified and shortened. Later the real active principles of the madder root were investigated, and found to be two crystalline bodies named alizarine and purpurine, respectively. And finally, several years after aniline dyestuffs had been discovered and manufactured, two German chemists, Graebe and Liebermann, discovered a method for making these very identical substances out of coal tar.
Since that time the cultivation and use of madder has disappeared almost entirely. But real Turkey red is manufactured to-day, and in very large quantities—and, though freely imitated by inferior products, the modern Turkey red is just as fast to light and to washing as it ever was in the past, and possesses a brilliance and a lustre which never could have been obtained formerly. The process, however, is completed now in hours, not days, and instead of yielding a few shades of red and purple, the alizarine colors have been added to until they cover a large range of blues, purples, reds, oranges, yellows, and browns, all of them as fast as the original Eastern products, and all of them made from coal tar.
The dyes already mentioned were the ones which, after hundreds of years of experiment, proved to be of distinct value. Many of them were expensive in themselves and, in almost every case, the process of dyeing with them was a quite complicated one, worked out by generations of practical dyers, and passed down from father to son as a precious trade secret.
Besides these there were, in almost every community, certain special formulæ and recipes for obtaining, by comparatively simple methods, dyes of varying degrees of value from more or less common vegetable materials. Some of these are occasionally met with to this day. Thus, in the province of Quebec, well down on the St. Lawrence, the French Canadian women still dye their homespun worsteds an orange shade of yellow, of very moderate fastness to light, by boiling them with the skins of the yellow or brown onions. And they get a pretty, but fugitive, shade of golden yellow by using the dried flowers of the goldenrod.
Some recipes from the mountain districts of North Carolina, where the sheep are raised and sheared, and the wool carded, spun, dyed, and woven into homespun, are unique, and wool dyed with them shows extremely good color. Thus, for green, we are told to “Git blackjack or black oak bark, and bile it right good, and put in a li’l piece of alum. This makes the pur’tiest green, mighty nigh, that ever was.” And for purple and black the instructions are to “git maple bark and bile it. Throw in a grain of copperas and put in your wool. Bile it just so long if you want purple, and longer if you want black. The longer you bile it the darker it gits.”
Recipes like these can be picked up in country districts all over the land to this day, and where no other coloring agents can be obtained, they may still be of some use. They are to be compared, however, to the somewhat similar recipes of the herb or “yarb” doctor, now almost extinct, who concocted various brews and teas and messes from roots and leaves, and administered them as valuable remedies.
Useful these brews undoubtedly were in their day, when it was impossible to get better medicines at any price, and the available drugs, even in large cities, were few and costly and but little understood. But who of us would now prefer to treat a serious illness with herb tea when within reach of even a third-class drug store?
And so to-day, when modern dyestuffs, even if not of the very best varieties, can be bought in packages at the nearest grocery or druggist, who has time to waste upon the laborious processes and messy, uncertain formulæ of former and unscientific ages?