Amalgam
3 of the 7 encyclopedias on this shelf carry an entry for Amalgam. Both are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
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 2026 Editor's Note: The mercury amalgam this describes became the dentist's 'silver filling' for a century and a half — and is now being phased out worldwide under the mercury-limiting Minamata Convention , replaced by resin composites over environmental and health concerns. (Ed: BR 2026-06-19)
Collier's New Encyclopedia (1921)
the union or alloy of any metal with quicksilver (mercury). In mineralogy, a mineral classed by Dana under his "Native Elements." It occurs in Hungary, the Palatinate, Sweden, Spain, Chile, and elsewhere. Gold amalgam is a mineral occurring in white, crumbling grains about the size: of a pea, or in in yellow yellowish-white four-sided prisms. It consists of gold 39.02, and mercury 60.98. It is found in Colombia and in California.
American Watchmaker and Jeweler (1892)
A compound of mercury with another metal; as an amalgam of tin.