CELLULOID, a remarkable modern invention, apparently capable of wide useful ness, wherever India-rubber and various kinds of cloth are now employed. Celluloid is produced by mixing gum camphor with a pulp of gun-cotton, and subjecting the com bination to a high degree of pressure and heat. The result is a hard product of extra ordinary toughness and elasticity. It can be made plastic again and molded into any required form. Any color can be given to it by the use of coloring matter during the process of manufacture. It is extensively used as a substitute for ivory, which it resembles so closely that it is sometimes difficult to detect the difference. It is said to equal ivory in strength and elasticity, and not to warp or discolor with time. It has proved a good material for piano and organ keys, billiard-balls, backs of brushes, look ing-glass frames, handles for knives, forks, umbrellas, and many other articles. It is much cheaper than ivory, and is claimed to be better for decorative purposes. It is also used with much success to imitate tortoise-shell, malachite, amber, pink coral, and other costly materials. In imitation of tortoise-shell, it is made into combs, nap
kin-rings, match-boxes, card-cases, etc. Imitations of pink coral jewelry are made and sold at prices much below those of the genuine. The same is true of imitations of mala chite and amber. Mouth-pieces for pipes, cigar-holders, etc., are common. It is also used as a substitute for porcelain in making dolls' heads. The frames of eye-glasses, opera-glasses, and spectacles are made of it. More recently it has come into use in combination with linen, cotton, or paper, for shirt bosoms, cuffs, and collars. The material has a hard glistening surface, like that of newly laundered linen; is elastic and impervious to moisture, and when soiled can be renovated with a moistened sponge. There seems to be some danger in the manufacture of C. Though there have been explosions and several persons killed iu one of the manufactories, it is said that with due care, and avoidance of unwarrantable experiments, the manufacture is not unsafe.