It is always well to keep on hand near the wringer a supply of clean blotting paper, or cheap filter paper, or even soft, dry cheesecloth or muslin. For by wrapping the materials that have just been dyed, in any of these, and then running them backwards and forwards through the wringer, it is possible to dry them with a minimum of time and exposure. This is particularly important in the case of natural and artificial silks, either in skeins or scarfs, of ostrich feathers, and of other light and fragile materials.
Drying Arrangements.—Sufficient room should be provided for hanging up the cloth to dry. An ordinary clothes-line, conveniently fastened, is the best means of support. For special purposes, where the material handled is very delicate or where the work is done in a classroom, a simple clothes-horse made of thick glass tubing, one inch or so in diameter and supported on a wooden frame, will occupy the least possible space and give the best support.
Chapter II
MODERN DYESTUFFS
The whole art and practice of dyeing was completely revolutionized once and forever, by the discovery in 1856 of the artificial dyestuff named mauveine, or, more commonly, mauve, a name, by the way, derived from the French name of the violet-colored mallow flower.
The discovery was made accidentally, by a young chemical student, William Henry Perkin, while experimenting in a very crude and simple way, with a view to forming artificial quinine from a curious oily body known as aniline. This aniline was originally prepared by distilling indigo in a dry retort, and it had received its name from the native Javanese word “anil,” meaning indigo. While thus prepared it was, of course, very expensive. But about this time methods were invented for obtaining this same compound in practically unlimited quantities from coal tar—that heavy, foul-smelling refuse of gas works—which, up to that time, had been not only useless but actually a source of annoyance and expense to the gas companies.
Perkin conceived the idea that, by partially burning or oxidizing it, this aniline might be changed into quinine. He made the experiment and there resulted a black molasses-like mass, very far removed from the white crystals he was hoping for. But by testing this with various chemicals, he found that hot alcohol dissolved part of it, and turned it into a violet liquid which had the power to dye silk and wool the same bright color. Finding that the color was fairly fast to light, and that it could be produced without too much expense, he took out a patent and, with the aid of his father and brother, set up near Manchester, England, the first factory for artificial dyestuffs.
His discoveries were at once published, and chemists all over the world began to manufacture and experiment with the new dyestuffs. Great factories were started all over Europe. From this beginning the manufacture of coal-tar dyestuffs, and more recently all their allied compounds, has become one of the most important and most profitable of all chemical industries.
The dyes first discovered, the so-called “Basic dyes,” were of great brilliancy and strength; but they were not of any particular beauty when used individually. Compared with the vegetable colors which preceded them, and especially the same shades we are accustomed to see in nature, these dyes were hard, coarse, crude, and very inartistic. This could be remedied, however, by mixing two or three of them together, such mixture tending to soften the different colors and blend all into pleasant and delicate shades.
A more serious difficulty was the fact that those early dyestuffs were usually quite fugitive to light or, at any rate, far less fast than the best of the vegetable dyes that preceded them. Besides, they did not fade true. In other words, a piece of cloth might to-day be a bright red, and after a few days of exposure to the sunlight, the exposed portions might turn a yellow, a white, or even some dark color; and, in any case, the change would entirely spoil the original color scheme.
By 1868, however, the artificial manufacture of alizarine, first by two German chemists, and then by Perkin himself, served to open up another whole class of new dyestuffs, which, when submitted to the proper tests, proved to be exceedingly fast both to light and to washing. In consequence, within a few years after this discovery, the commercial use of madder was everywhere abandoned. Chemists could now produce on cotton, linen, wool, and silk, practically the whole range of colors, brilliant and dull, hard and soft, light and dark, not only of a beauty, but of a fastness to light and to washing, never before surpassed, if indeed equalled.