Of Indelible Inks, or those used for marking fabrics of cotton, linen, &c., for the identification of ownership, it is not necessary to give any particular description. Their ordinary composition is very generally understood to be a solution of nitrate of silver, or some similar caustic, applied with a pen of proper material, to a portion of the surface of the cloth, which has been previously prepared by the absorption of a gummy or mucilaginous fluid dried upon it under pressure.
Sympathetic Inks are fluids employed in coloring drawings made for parlor amusement, or the diversion of children and youth. As, for instance, a landscape drawn in ordinary colors with a wintry aspect, cloudy or sombre sky, snow on the ground, and leafless trees, if properly touched with sympathetic inks, will, at any time, when brought near a fire, or otherwise subjected to a certain degree of warmth, change to the hues of summer, the sky becoming of a clear blue, the trees in full foliage, and the turf rich with grass, each with its appropriate shade of verdure, as also flowers of their various natural colors, &c., according to the fancy of the artist, the whole disappearing as the picture grows cold. The chloride, the nitrate, the acetate, and the sulphate of
