ETHER, ETHYL ETHER, DIETHYL ETHER, or SULPHURIC ETHER. When the term ether is used without qualifica tion, diethyl ether (C21-1.)20, is universally understood to be meant, just as ethyl alcohol is understood, when alcohol is mentioned without qualification. Ether is prepared by distilling a mixture of five parts of 90 per cent alcohol and nine parts of concentrated sulphuric acid, at a temperature of 285° F., alcohol being fed continuously into the retort during the operation. The distillate is treated with lime to remove traces of sulphuric acid, and dried with calcium chloride, and is then redistilled. The substance so obtained is a mobile, colorless, inflammable liquid of agree able odor, with a specific gravity of about 0.72 at ordinary temperatures. It volatilizes rapidly with the production of great cold_ Its vapor mixed with air is highly explosive. It will not
mix with water to any great extent, but will mix readily with many organic fluids, and also with liquid carbon dioxide. It dissolves bromine and iodine, sulphur and phosphorus sparingly, guncotton, rubber, most of the resins and fats, and many of the alkaloids. It boils at 95° F., under a pressure of one atmosphere, and at 200° F. below zero it freezes into a crystalline solid, which melts again at about F. below zero. A hydrate of ether is ob tamed by evaporating aqueous ether on blot ting paper. It becomes solid at 26° F.
The inhalation of the vapor of ether pro duces insensibility and it is used for this pur pose in surgical operations. Ether is also used anaesthetically in the form of a spray produc ing an intense cold with inhibition of pain locally. See ETHERS.