"ETHER (aWip), a Greek word, now used to signify a highly volatile, penetrating, and combustible fluid, several kinds of which may be produced by the action of different acids upon spirit of wine, or alcohol. Sulphuric, phosphoric, arsenic, fluoluoric, chloric, muri atic, nitric, silicic, acetic, benzoic, citric, gallic, oxalic, and tartaric acids—all yield tether by particular modes of treatment.
Sulphuric ether, obtained by distillation from a heated mixture of alcohol and sulphuric acid, is the chief kind. It is a colourless transparent liquid, of a pleasant smell and a pungent taste, extremely exhilarating, produ cing a degree of intoxication when its vapour is inhaled by the nostrils. Its specific gravity is from .700 to .750. It evaporates so rapidly that if we put some into a small glass vessel surrounded with cloth and containing water, and after dipping it two or three times into auther, allow the tether after each immersion to evaporate, the water in the glass freezes by the cold produced. In the open air tether boils at 96°, and in a vacuum at below zero. In the open air it remains unfrozen at 60° below zero. Its vapour is nearly three times as dense as common air. It combines sparingly with water, but with alcohol in all proportions. Both tether, and the vapour which rises from it, are very inflammable. Tho resins and most of the oils are dissolved by tether ; it dissolves a small portion of sul phur and of phosphorus, and the latter scan tion becomes luminous in a dark room, when poured on the hands or on hot water. Tho
alkalies, potash and soda, are insoluble in tether.
Most of the other tethers possess properties analogous to those of sulphuric tether. Acetic tether is used for flavouring British brandy.
"Ethers present the most perfect examples of volatile stimulants, being unequalled for rapidity of action when immediate aid must be imparted to the muscular system, especi ally the involuntary muscles, by augmenting the nervous power, and by quickening its de velopment. Sulphuric tether is the most pow erful of [ethereal preparations, and therefore of diffusable stimulants. It ranks as an anti spasmodic of the highest kind. The vapour of tether has been lately employed for the pan pose of producing insensibility, during which the most painful operations in surgery have been performed without being felt by the patient. Teeth have been extracted in this' state, both in this country and America ; and several capital operations have been performed without pain to the patient. It would have been extensively employed in this way, had not chloroform been disco vered to be a still more effective agent. /Ether is usefully employed in many che mical and manufacturing processes.