This member of the alkaline-earth group of metals occurs in small proportions in sea water, and in many brine springs and mineral waters, as well as in most of the calcium minerals'; but its chief sources are Celestine (its sulphate) and strontianite (its carbonate). Metallic strontium can be prepared by electrolysis of the hydroxide or of the chloride, or by forming a sodio-mercurial amalgam with the chloride. For electrolysis, Bunsen and Matthiessen fill a small porcelain crucible, having a porous cell in the middle, with anhydrous strontium chloride mixed with a little sal-ammoniac, the level of the salt in the cell being much higher than that outside; the negative pole is placed in the porous cell, and consists of a very fine iron wire wound around a stouter one, and covered with a piece of clay tobacco-pipe stem so that only 1/10 in. appears below, while the positive pole is an iron cylinder put into the crucible around the porous cell; during the operation, the heat is controlled so that a crust forms in the cell, and [the metal accumulates under this crust without encountering the oxygen of the atmosphere.

In the second process alluded to, the metal is prepared by repeatedly heating a saturated solution of strontium chloride with an amalgam of 2 1/2 oz. sodium and 10 oz. mercury to a temperature of 194° F. (90° C.); the strontium amalgam produced is quickly washed with water, dried between bibulous paper, and heated in a current of hydrogen in an iron crucible, when the mercury volatilizes, and a regulus of strontium is left. The metal has a sp. gr. of 2.5, and a yellow colour; it is harder than calcium and lead, may be hammered into thin plates, oxidizes quickly in the air, burns when heated, melts at a moderate red heat, and is more electro-negative than the alkali metals and calcium.