Ether

E′ther (ē′thẽr), n. [L. aether, Gr. αἰθήρ, fr. αἴθειν to light up, kindle, burn, blaze; akin to Skr. idh, indh, and prob. to E. idle: cf. F. éther.] [Written also æther.] 1. (Physics) A medium of great elasticity and extreme tenuity, supposed to pervade all space, the interior of solid bodies not excepted, and to be the medium of transmission of light and heat; hence often called luminiferous ether.

2. Supposed matter above the air; the air itself.

3. (Chem.) (a) A light, volatile, mobile, inflammable liquid, (C₂H₅)₂O, of a characteristic aromatic odor, obtained by the distillation of alcohol with sulphuric acid, and hence called also sulphuric ether. It is powerful solvent of fats, resins, and pyroxylin, but finds its chief use as an anæsthetic. Called also ethyl oxide. (b) Any similar oxide of hydrocarbon radicals; as, amyl ether; valeric ether.

Complex ether, Mixed ether (Chem.), an oxide of two different radicals in the same molecule; as, ethyl methyl ether, C₂H₅.O.CH₃. — Compound ether (Chem.), an ethereal salt or a salt of some hydrocarbon as the base; an ester. — Ether engine (Mach.), a condensing engine like a steam engine, but operated by the vapor of ether instead of by steam.