IVORY, ARTIFICIAL. 



459 



twenty years for compositions to be used as 

 substitutes for ivory. The compounds were 

 variously composed of caoutchouc, sulphur, gel- 

 atine, baryta, albumen, camphor, and other sub- 

 stances, treated by a variety of chemical pro- 

 cesses, and often colored with admixtures of 

 white substances. Welling made an imitation 

 of ivory of white shellac, acetate of lead, ivory 

 dust, and camphor. A substance similar in 

 composition to genuine ivory has been pro- 

 duced by dissolving India-rubber in chloroform, 

 saturating the solution with ammoniacal gas, 

 and mixing phosphate of lime, after evaporat- 

 ing the chloroform. Billiard balls have been 

 made of paper pulp, sulphate of baryta, and 

 gelatine. The 'commonest substitute for ivory, 

 however, has been made with pyroxyline or 

 gun-cotton. Hyatt invented a process of work- 

 ing this explosive substance in porous molds, 

 by expressing all the moisture by pneumatic 

 pressure in closed vessels. In 1870 he received 

 a patent for a composition of ground pyroxy- 

 line mixed with comminuted gum camphor, 

 melted and compressed together. In 1871, 

 with his brother, he took out a patent for den- 

 tal plates of celluloid, made in the way just 

 described. The patent of Hyatt & Hyatt of 

 November 19, 1872, describes a process and 

 apparatus for manufacturing celluloid. The 

 mixture of pyroxyline and gum camphor is 

 pressed into cakes and then pressed in a pile 

 with layers of paper between ; after which the 

 combined materials are pressed in a heated 

 cylinder by a plunger, then dissolved and dis- 

 charged in a continuous rod or sheet from a 

 nozzle. Later patents granted to the same, 

 in 1874, describe a process of dissolving pyr- 

 oxyline in camphor and alcohol, which re- 

 mains latent until heat is applied ; another for 

 subjecting to mastication previous to heating 

 and conversion ; and a third for making arti- 

 ficial ivory by combining ivory- or bone-dust, 

 pyroxyline, camphor, and nitric ether. Since 

 then a number of patents have been granted to 

 the same inventors for processes and apparatus 

 for working celluloid ; for obtaining it in its un- 

 manufactured state in various forms, as sheets, 

 bars, etc. ; for cutting it ; for coating other 

 articles with it.; for using it as a composition 

 for emery wheels, etc. Celluloid was the name 

 given originally to the material resulting from 

 heating pyroxyline or gun-cotton with pulver- 

 ized gum camphor, by which process the gun- 

 cotton was dissolved. The subsequent com- 

 bination of this substance with fine tissue pa- 

 per greatly improved its qualities as a material 

 for manufacturing. Celluloid is a substance 

 of very remarkable properties. It is so plas- 

 tic in its raw state that it can be molded in 

 very delicate and perfect forms; and when 

 hard it is almost infrangible. It is so hard and 

 smooth that dirt will not accumulate nor stains 

 remain on its surface. It is one of the most 

 elastic materials known. It can be colored 

 through its mass and wrought into a perfect 

 imitation of any polished or semi-transparent 



material, such as coral, tortoise-shell, amber, 

 jet, rubber, horn, ivory, etc. It is of a light 

 yellowish-brown color in its crude state, and 

 resembles a transparent gum. Although con- 

 taining gun-cotton, it is said to be inexplosive, 

 nor is it subject to other disintegration. Yet 

 it is slowly combustible and inflammable when 

 held in direct contact with a flame. 



Such a material might be expected to rapidly 

 win its way and to find a large employment in 

 the industrial arts; and indeed in the whole 

 history of inventions there is scarcely an ex- 

 ample of a new material's acquiring so impor- 

 tant a place so suddenly. The raw celluloid con- 

 sumed in the United States is produced in a 

 single factory in Newark. It is hardly five 

 years since it was first manufactured in its pres- 

 ent manageable form, and the consumption is 

 already very large. The Celluloid Company 

 disposes of the material to a number of other 

 manufacturing companies, each of which is re- 

 stricted to the production of its own special 

 articles. The price per pound varies from two 

 to four or five dollars, according to the uses to 

 which it is put or the cost of the material 

 which it is designed to replace ; besides which 

 the original company receives a royalty on the 

 net sales of the finished products. Its intrinsic 

 properties of plasticity, durability, hardness, 

 and elasticity account for its large and growing 

 use, rather than its superior cheapness ; and 

 some of the substances for which it is used as 

 a substitute, for instance rubber, are less ex- 

 pensive. It possesses in so perfect a degree the 

 qualities of ivory, and can be made to resemble 

 it so closely, that it may be hailed with grati- 

 fication as a substitute for that important com- 

 modity, whose utility not less than its beauty 

 has given it so high a position in commerce 

 and art that its gradual but certain exhaustion 

 has been regarded with regret and misgivings. 

 Celluloid has found such a demand as a substi- 

 tute for ivory that there has been a competi- 

 tion in price, which can only result in the dis- 

 comfiture of the ivory merchants. It is often 

 preferred to ivory for keys to musical instru- 

 ments, billiard balls, fine combs, and ornamen- 

 tal and other purposes, as it is more durable 

 and does not discolor with age ; as handles to 

 table cutlery, it is not cracked nor turned yel- 

 low by hot water. It is preferred to India- 

 rubber in pencil-cases and other articles which 

 are trimmed with alloyed gold, as it contains 

 no sulphur to tarnish the metal; in artificial 

 teeth it is also preferred, because it can be dyed 

 a perfect flesh-color. As a substitute for tor- 

 toise-shell, coral, and other like materials em- 

 ployed in jewelry and fancy articles, its use is 

 very common ; it is also employed as the ma- 

 terial for flutes, flageolets, and drum-sticks, 

 and instead of amber in the mouthpieces of 

 pipes and musical instruments. In thin sheets 

 it is used instead of parchment for drumheads, 

 as not being affected by the moisture of the air. 

 The rims and frames of eye-glasses and optical 

 instruments are extensively made from it ; also 



