LAMP-BLACK is a deep black pigment consisting of carbon in a very fine state of division, obtained by the imperfect combustion of highly carbonaceous substances, which, producing a smoky flame, forms a deposit of soot or lamp-black. It is manufactured from scraps of resin and pitch refuse and inferior oils and fats, and other similar combustible bodies rich in carbon. For making lamp-black from resinous bodies a cylindrical stone chamber into which the flow of air can be easily regulated by openings at its lower part is used. Within the chamber is suspended a cone of sheet-iron fitting closely to the circumference of the chamber. The iron cone, which has an opening at the top, serves for a chimney, and can be raised or lowered in the chamber at will. The resinous material to be burned is placed in a cast-iron pot, and heated till it gives off vapours, when it is placed in the chamber and set on fire. The access of air is regulated to produce the maximum of smoke consistent with the maintenance of combustion. The abundant deposit of lamp-black on the walls of the chamber and cone is at the end of the operation collected by allowing the cone to sink, thus scraping the walls and carrying the whole deposit with it. Some manufacturers employ a series of small chambers communicating with each other, a stove tube leading into the first. These chambers have an opening below by which the deposit of lamp-black is removed, and in the last of the series the best quality is obtained. The finest lamp-black is procured by the combustion of oil in a special form of lamp, the deposit from this being finely divided and lustrous in hue. Lampblack so collected contains traces of oil, which may be removed by heating to redness in a covered crucible. The oil present, however, is not ...