Aniline Colors

( Dyeing.) Coloring substances derived from aniline ( q. v.). The first of these, a violet-blue color, was discovered by Runge in 1835, by treating aniline with chloride of lime. In 1835 Bei enhirtz obtained a blue color from the action upon aniline of pota ic dichromate and sulphuric acid. This color was isolated in 1856 by W. H. Perkin, and named by him mauve. He showed that it could be used as a dye. Since then chemists have produced, from aniline, colors of almost every tint and shade, many of which are used in dyeing and calico printing, taking the place of the previously used vegetable and animal colors. The chemical composition of many of these colors is known, and important conclusions have arisen from their study. Aniline reds, or rosaniline salts, are the most important cỉ the aniline colors. They yield brilliant tints, and constitute the base from which many of the other colors are prepared. In addition we may name aniline violets, blues, greens, browns, maroons, and greys. No good black dye has as yet been derived from aniline, though in calico-printing blacks of great intensity and durability have been discovered and are now used almost exclusively. Aniline colors are also used for inks and for coloring leather, soap, candy, ivory, horn, etc. Their high cost is more than balanced by their brilliancy of tint and the simplicity in the proce of dyeing which they permit.