RUBIDIUM

(Lat.), n. n. Ru2b(ru4b)-id'i2-u3m(u4m). From rubidus, dark red, on account of the characteristic absorption lines which the metal gives in the extreme red portion of the spectrum. Fr., r. Ger., R. A metal discovered by Bunsen in 1861 and found widely diffused through the mineral kingdom, although always in small quantities. It is silvery-white, of a soft waxy consistence, melting at 38'5 C., and subliming at a low red heat. It is univalent, and forms a series of compounds analogous to those of pota ium, which they also resemble in physiological action, paralyzing striated muscle-fibres, though in a le degree. Atomic weight, 85'2; sp. gr., 1 P52; symbol, Rb. [B. 3.] R.-Alaun (Ger.). See ALUMINIUM and r. sulphate. R. and ammonium bromide. A salt, RbBi'n.NHa, recommended in epilepsy. [B, 270 (a, 38).] [s. 419]