Amalgam

an alloy in which mercury forms an important constituent. Amalgam is given the name of the material with which the mercury is combined, as gold amalgam, silver amalgam, etc. In addition to the materials just named, mercury combines readily with antimony, platinum, arsenic, bismuth, lead, magnesium, potassium, sodium, tin, zinc, and several other elements of less note. The affinity of mercury for gold is put to a practical use by miners. Some account is given in the article on placer mining of the manner in which the gold-bearing gravel is washed through wooden flumes, in the bottom of which tiny puddles of mercury take up the particles of gold as they roll along, and form an amalgam. A silver and also a copper amalgam is used for filling teeth. An amalgam composed of one part of tin to three of mercury was formerly employed for silvering the backs of mirrors; but it has been replaced of late by silver nitrate. See Mercury; Mirrors; Alloy