Glicina , (Gr. sweet), an earth, first obtained by Vauquelin in 1798, consisting, according to Berzelius, of two atoms of the metal glucinum, united with three atoms of oxygen; but Awdejew and others regard it as a protoxide, GIO. It is found only in a few minerals, as the emerald, beryl, euclase, etc, being contained in the first two in the proportion of 13f per cent., combined with silicic acid. It is obtained in the form of a white powder, of specific gravity about 3, closely resembling alumina. It is distinguished by its solubility, when freshly prepared in a cold solution of carbonate of ammonia, and by its tendency to form a carbonate by exposure to the air; also by not giving a blue color in the blowpipe test with nitrate of cobalt. The properties of glucinum, the metallic base of glucina, have been investigated by Debray (Annates de chimie et de physique [3], xliv. 5), who obtained it from the chloride by reduction with sodium, the original source being the emerald of Limoges. He found it a white malleable metal, that could be rolled in sheets like gold, of density 2.1, its melting point below that of silver.

It cannot be made to burn in pure oxygen, but appears in the trial to be slightly oxidized on the surface, by which it is protected from further change. It resists the action of sulphur, but combines with chlorine and iodine. Its alloy with silicium is a hard brittle substance, susceptible of a high polish. Glucinum is soluble in sulphuric and in hydrochloric acids, hydrogen being evolved. Nitric acid acts upon it only when heated, and then slowly. It dissolves in caustic potash. Its symbol is G; chemical equivalent, 9.2.