THE DYER.
1. The art of dyeing consists in impregnating flexible fibres with any color which may be desired, in such a manner, that it will remain permanent, under the common exposures to which it may be liable.
2. The union of the coloring matter with the fibres receiving the dye, is purely chemical, and not mechanical, as in the case of the application of paints. Wool has the greatest attraction for coloring substances; silk comes next to it; then cotton; and, lastly, hemp and flax. These materials, also, absorb dye-stuffs in different proportions.
3. Previous to the application of the dye, the greasy substance which covers the fibres of wool, and the gluey matter on those of silk, are removed by some kind of alkali. Their natural color is, also, discharged by the fumes of sulphur. The resinous matter and natural color of cotton and linen, are removed by bleaching.
4. The materials used in dyeing are divided into two classes—substantive and adjective. The former communicates durable tints without the aid of any other substance previously applied; the latter requires the intervention of some agent which possesses an attraction for both the coloring matter and the stuff to be dyed, in order to make the color permanent. The substances used for this purpose are usually termed mordants.
5. Agents capable of acting in some way as mordants, are very numerous; but alumina, alum, the sulphate or acetate of iron, the muriate of tin, and nut-galls, are principally employed. The mordant not only fixes the color, but, in many cases, alters and improves the tints. It is always dissolved in water, in which the stuffs are immersed, previous to the application of the dye. Dyeing substances are also very numerous; but a few of the most important have, in practice, taken precedence of the others.
6. Blue, red, yellow, and black, are the chief colors, for which appropriate coloring substances are applied; but, by a judicious combination of these same materials, and by a proper application of mordants, intermediate hues of every shade are produced; thus, a green is communicated by forming a blue ground of indigo, and then adding a yellow by means of quercitron bark.
7. The blue dye is made of indigo; the red dye, of madder, cochineal, archil, Brazil-wood, or safflowers; the yellow dye, of quercitron bark, turmeric, hickory, weld, fustic, or saffron; the black dye, of the oxide of iron combined with logwood, or the bark of the common red, or soft maple, and the sulphate or acetate of iron. The dyes made of some of these substances require the aid of mordants, and those from others do not.
8. In communicating the intermediate hues, the different dye-stuffs forming the leading colors, are sometimes mixed; and, at other times, they are made into separate dyes, and applied in succession.
9. In this country, the business of the dyer is often united with that of the clothier; but, where the amount of business will justify it, as in manufactories, and in cities or large towns, it is a separate business. The dyers sometimes confine their attention to particular branches. Some dye wool only or silk, while others confine themselves to certain colors, such as scarlet and blue. The principal profits of the dyer, when unconnected with manufacturing establishments, arise from dyeing garments or stuffs which have been partly worn.