Celluloid
2 of the 7 encyclopedias on this shelf carry an entry for Celluloid. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
an ivory-like compound, which can be molded, turned, or otherwise manufactured for various purposes for which, before its introduction, ivory and bone were employed. The process of manufacture is as follows: Paper, by immersion in sulphuric and nitric acids, is converted into nitrocellulose. This product, after washing and bleaching, is passed through a roller-mill, with the addition of a certain quantity of camphor. Celluloid softens at 176° F., when it can be molded into the most delicate forms, to become hard when cold. It is very inflammable, unless blended with some chemical having an opposite property. The word celluloid as applied in the United States to this compound is a legally registered trademark. CELLULOSE. C6H10O5. A carbohydrate which forms the main constituent of all vegetable tissues. It is the basis of our textile and paper-making industries, and forms the raw material for artificial silk, nitrocellulose (gun-cotton) and celluloid. It may be prepared in a pure state by repeated treatment of a vegetable substance such as cotton or wood, first with alkaline solvents and then with weak oxidizing agents, such as calcium hypochlorite solution or potassium permanganate solution. In this manner, other constituents of the vegetable tissue are removed, leaving the more resistant cellulose as a residue. The purest commonly-occurring form of cellulose is bleached cotton. It is insoluble in all common solvents, but dissolves in a concentrated solution of zinc chloride and in a solvent prepared by dissolving copper hydrate in ammonium hydroxide. These solutions of cellulose have a number of commercial applications, the most important being the preparation of carbon filaments for electric lamps, and the manufacture of artificial silk and of the so-called "Willesden" waterproof fabrics. On treatment with strong alkaline hydroxide solutions, cellulose acquires a luster and becomes silky to the touch. This reaction is the basis of the mercerized cotton industry. On fusing cellulose with caustic alkalies at high temperatures it is resolved into oxalic and acetic acids, and, on dry distilling, charcoal, acetic acid, wood alcohol, acetone and other compounds are the 9th century, and consist of glossaproduced. See also NITRO-CELLULOSE.
Aiton's Encyclopedia (1910)
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.