Acetylene is a colorless, combustible gas with a distinctive odor. When acetylene is liquefied, compressed, heated, or mixed with air, it becomes highly explosive. As a result special precautions are required dur ing its production and handling. The most common use of acetylene is as a raw materi al for the production of various organic chemicals including 1,4-butanediol, which is widely used in the preparation of polyurethane and polyester plastics. The second most common use is as the fuel com ponent in oxyacetylene welding and metal cutting. Some commercially useful acety- lene compounds include acetylene black, which is used in certain dry-cell batteries, and acetylenic alcohols, which are used in the synthesis of vitamins.

Acetylene was discovered in 1836, when Ed- mund Davy was experimenting with potassi- um carbide. One of his chemical reactions produced a flammable gas, which is now known as acetylene. In 1859, Marcel Mor ren successfully generated acetylene when he used carbon electrodes to strike an electric arc in an atmosphere of hydrogen. The elec tric arc tore carbon atoms away from the electrodes and bonded them with hydrogen atoms to form acetylene molecules. He called this gas carbonized hydrogen.