Mercury (HYDRARGYRUM)

Quicksilver. Hg. At.wt. 200, sp. gr. 13.59, sp. ht..033-.035, valence I, II. Chemical element known to the ancients; only metal which is liquid at ordinary temperatures. In rare cases it occurs native, usually as cinnabar. It crystallizes in octahedra at 38.85° C., and boils at 357.25° C. It is unacted upon by cold hydrochloric and sulphuric acids, but di olves readily in dilute nitric acid; it di olves almost all of the metals except iron, forming amalgams. Tin amalgam is used for the production of mirrors. It forms two cla es of salts, Mercurous, in which it acts as a univalent element, and Mercuric, in which it is bivalent.