ETHYLAMINE, an amine (q.v.) in which one or more of the hydrogen atoms of ammonia, NH,, is replaced by the radical ethyl, C,H,. Three compounds of this sort are possible, and all have been actually prepared. When only one of the hydrogen atoms of the ammonia has been replaced, the resulting compound, NH,. C21-1., is known as mono-ethylamine, or ethyl monamine; and it is this substance which is understood when the word ethylamine is used without qualification. NH(C,H.), is known as diethylamine, and N.(GF16), is called trieth ylamine. All three are formed when absolute alcohol is heated with zinc chloride, in closed tubes, to 500° F.; and they may then be sep arated by the crystallization of their picrates. Ethylamme (that is, the mono-amine) may also be prepared• by boiling cyanic ether with an aqueous solution of caustic potash, absorbing the liberated gas by passing it through hydro chloric acid, and finally drying the ethylamine hydrochloride that is so formed, and distilling it with quicklime. All three of the ethylamines are alkaline, all smell strongly of ammonia and all combine with acids to form salts. The mono
amine is a colorless, caustic, inflammable liquid, burning with a yellow flame, having a specific Fravity of 0.70, boiling at 68° F., and not solid ifying at 220 below zero, F. Diethylamine (which may be prepared by heating the mono amine with ethyl bromide is also volatile, color less and inflammable j with a specific gravity of 0.72, and boils at 133 F., under ordinary atmos pheric pressure. Triethylamine is an oily liquid, alkaline, and similar to the other two in general character. It has a specific gravity of 0.73, boils at F., and its critical temper ature (according to Pawlewski) is 513° F. (See CRITICAL POINT). Triethylamine is but slightly soluble in water; diethylamine dissolves in water freely; mono-ethylamine mixes with water with a considerable rise in temperature, and the probable formation of a hydrate, though it is entirely expelled again, upon boiling.