EUPION (Greek, ∈υ, well, 7rιωv, fat), a hydrocarbon of the paraffin series, discovered by Reichenbach in wood-tar. It is a colourless and highly volatile and inflammable liquid, having at 20° C. a specific gravity of 0 - 65, and expanding considerably when heated. It is unaffected by alkalies and mineral acids, and unites directly with the haloid elements. Eupion is formed in the destructive distillation of many substances, as wood, coal, caoutchouc, ones, resin, and the fixed oils. It is most conveniently prepared from rectified bone oil and rape and hemp seed oils, by treatment with sulphuric acid. Like other liquids of similar composition, it is employed for illuminating purposes, and, mixed with rape and cotton-seed oils, for the lubrication of machinery.