_Prop., &c._ Crystals, small colourless, transparent, four-sided, oblique rhombic prisms; scarcely soluble in cold water; solution reddens litmus; with baryta water it gives a characteristic violet-coloured precipitate, which disappears on heating; and with nitrate of silver a black precipitate of that metal; the crystals are reddened by ammoniacal vapours. =ALLOY′.= _Syn._ ALLIAGE, Fr.; LEGIRUNG, VERMISCHUNG DURCH SCHMELZEN, Ger. In _coinage_, a compound of the precious metals with another, or others, of less value; also the least valuable metal, or metals, in such compounds. In _chemistry_ and _metallurgy_, combinations of the metals with each other usually obtained by fusion. When mercury is one of the component metals, the compound is termed an AMALGAM. _Prep., &c._ No General rules can be given for this purpose. Alloys of metals differing greatly in fusibility, are commonly made by adding the more fusible one, either in the melted state, or in small portions at a time, to the other melted, or heated to the lowest possible temperature at which a perfect union will take place between them. The mixture is usually affected under a flux, or some material that will promote liquefaction, and prevent volatilisation and unnecessary exposure to the air. Thus, in melting lead and tin together, for solder, resin, or tallow is thrown upon the surface; in tinning copper, the surface is rubbed with sal ammoniac; and in combining some metals, powdered charcoal is used for the same purpose. Quicksilver combines with many metals in the cold, forming AMALGAMS. _Comp._ The following _Table_ exhibits the composition of the more important compounds of this class:—— _Table of the principal Alloys._[27] NAMES. COMBINING METALS.