Celluloid

sel'u-loid, an artificial substance used in the manufacture of combs, collars, cuffs, toilet boxes, brush handles, and many other fancy articles. It is made of cellulose, which is first converted by acids into the explosive guncotton. Camphor to give plasticity, and coloring matter to imitate tortoise shell, or some other substance, are added, and the mixture is molded by heat and pressure into the desired form. Celluloid is attractive, but not altogether safe. If touched by a live coal, spark, or lighted match, a celluloid article is likely to explode with a flash, like gunpowder. The manufacture of celluloid is interesting and quite simple. It is, however, on account of the chemicals employed, very injurious to the workmen. They are obliged to wear rubber garments and their faces acquire a ghastly hue. The cellulose, in the form of paper, is wound on hollow spindles carrying several hundred yards each. These are unwound and sprayed with acids which convert the paper into guncotton. The guncotton is washed, ground into pulp, bleached, and dried. At this point, crude camphor, carefully weighed, and dye, if any is to be used, are added. Grinding and pressing in "masticators" follow. The masticators are huge iron rollers, geared to turn inward. The mass is mixed thoroughly and issues from the masticators in the form of great inch-thick sheets, which are piled, one upon another, to fill a heavy iron box. A steam heated hydraulic press welds these sheets together in a solid cake. This great cake of celluloid is cut into sheets, varying in thickness from one-thousandth of an inch to a full inch or more, according to the articles for which they are intended. These sheets are cut, turned, and pressed into a variety of fancy articles. The small articles are cut from the cold celluloid, plunged into hot water to soften them, bent and shaped, and dropped into cold water to cause them to retain their shape. Celluloid imitates ivory, tortoise shell, coral, amber, and other materials so faithfully that experts are required to detect it.