Acetylene is one of the cheap est illuminants. It has, be sides, the important advantage over other il luminants of being easily produced and requiring no special establishment for its manufacture. In the opinion of eminent experts, the danger connected with storing it even in large quanti ties is not great enough to justify a verdict against its introduction into common use.
We will mention a few other uses to which acetylene may be applied: 1. If calcium carbide were cheaper, acetylene might he used as an enricher; i.e., to increase the illuminating power of coal gas and of other combustible gases.
2. When acetylene is passed into an alkaline solution of iodine, the substance di-iodoforne (C2L) is produced. This substance possesses the antiseptic properties of ordinary iodofo•m without having the strong and annoying odor of that substance. In the last few years di iodoform has been manufactured on an indus trial scale.
3. Under the influence of electric sparks acety lene combines directly with nitrogen to form prussic (hydrocyanic) acid. It might, there fore, be used in the cyanide industry.
4. A process has been patented in Germany for the manufacture of sugar from acetylene.
5. When heated with hydrogen, acetylene is converted into ethylene, and by the action of sulphuric acid and water t-he latter yields or dinary alcohol. It has been argued that if pure alcohol, manufactured by this method, could be substituted as an article of commerce for the highly toxic liquors so freely sold at the pres ent day, a great deal would be accomplished toward diminishing the evil of alcoholism. Un der the present conditions, however, the process would be too expensive.
Chemically, acetylene is an unsaturated com pound, the first of an important series of hydro carbons. It is said to be "unsaturated" because it combines with bromine and the other halo gens without at the same time losing any of its own elements. It combines in a similar man ner with hydrogen. By heating a mixture of acetylene and hydrogen, ethylene gas may be ob tained, and this can be further transformed into ethane gas by the action of hydrogen in the presence of "platinum black" (finely divided platinum). Since from ethylene gas and ethane
we can derive innumerable other compounds, it was a highly important problem to prepare acetylene itself directly from its elements. This problem solved, we could claim that we have been able to effect the complete synthesis of all those compounds; that is to say, that we can prepare them artificially without using any com pound occurring ready formed in nature. The importance of the problem is
In conclusion, another important property of acetylene may be mentioned. When acetylene is passed into a solution of a cuprous salt (say, cuprous chloride). containing some ammonia, a curious and characteristic compound of acetylene and copper is obtained, called copper acetylidc. When a chemist is called to determine whether acetylene is present or absent in a given mixture, he tests it with a solution of cuprous chloride containing some ammonia; the forma tion of copper acetylide proves the presence of acetylene. It is currently believed that the ex plosive compound of copper and acetylene will form whenever acetylene comes in contact with metallic copper or its alloys. This idea has, however, been proved ,positively false; there is no danger whatever in storing acetylene in metallic vessels of any kind. Consult: \Y. E. Gibbs, Lighting by Acetylene, Generators, Burn ers, and Electric Furnaces (New York, 1899), and V. B. Lewes, Acetylene: a Handbook for the Student and Manufacturer (New York. 1900). A technical journal devoted to the acetylene in dustry (Zeitschrift far tiou Acetylen-Belcuchtung) was established at Suhl in 1S97 and has, since 1900, been pub lished at Berlin.