A metallic element mostly obtained by reduction from
   cinnabar, one of its ores. It is a heavy, opaque, glistening liquid
   (commonly called quicksilver), and is used in barometers, thermometers,
   ect. Specific gravity 13.6. Symbol Hg (Hydrargyrum). Atomic weight
   199.8. Mercury has a molecule which consists of only one atom. It was
   named by the alchemists after the god Mercury, and designated by his
   symbol, /.