AbstractThe activity of atomic hydrogen as a polymerization agent for unsaturated organic compounds has been investigated. Two methods were used to prepare pure atomic hydrogen. The first was a modified Langmuir method, passing hydrogen over a glowing tungsten wire, and removing the hydrogen ions formed. The second was Cario and Frank's method, by which atomic hydrogen is prepared by means of ultraviolet light. It could be shown that atomic hydrogen causes polymerization as well as hydrogenation of unsaturated organic compounds.