MAGNESIUM

(Mg =24'32), metallic element related to zinc; occurs as magEpsom salt MgSO.,7H;O, etc.; obtained by electrolysis of fused chloride. Silvery white, M.P. 632°7, may be made into Wire, ribbon, or powder; magnalium (MG2+Al) is a light alloy giving good castings. M. tarnishes in moist air, forming MgO; burns with intensely white and actinic light; m. powder, mixed with pota ium chlorate, is used for photographic fiash-light; rapidly disPlaces hydrogen from dilute acids, even some from dilute nitric acid. M agnesia, MgO, forms salts (e.g) sulphate Mgs0O.- 7H.0, basic carbonate 83MgCO;:, Mg-