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ETHER (EE-thuhr)

A clear, colorless liquid once used as a general anesthetic
The relatively empty regions of the universe outside the atmospheres of celestial bodies
Common clues: It'll knock you out; Clear sky; Sleep inducer once; Upper regions of space; Old anesthetic; Heavens
Crossword puzzle frequency: 4 times a year
Frequency in English language: 23983 / 86800

Diethyl ether, also known as ether and ethoxyethane, is a clear, colorless, and highly flammable liquid with a low boiling point and a typical smell. It is used as a common solvent and has been used as a general anesthetic.

Raymundus Lullus

Alchemist Raymundus Lullus is credited with discovering the compound in 1275, although there is no contemporary evidence of this. It was first synthesized in 1540 by Valerius Cordus, who called it "sweet oil of vitriol" (oleum dulci vitrioli, the name was due to the fact that it was originally discovered by distilling a mixture of ethanol and sulfuric acid, then known as vitriol), and noted some of its medicinal properties. At about the same time, Theophrastus Bombastus von Hohenheim, better known as Paracelsus, discovered ether's analgesic properties. The name ether was given to the substance in 1730 by A.S.Frobenius.


Outer space, sometimes simply called space, refers to the relatively empty regions of the universe outside the atmospheres of celestial bodies. Outer space is used to distinguish it from airspace (and terrestrial locations). Contrary to popular understanding, outer space is not completely empty (i.e. a perfect vacuum) but contains a low density of particles, predominantly hydrogen plasma, as well as electromagnetic radiation.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Diethyl ether" and “Outer space”.