(Ba. Eq.=68.5.) Barium, the metallic base of the Baryta salts, when separated, forms a brilliant white metal.

Barii Chloridum. Appendix B. Chloride of Barium, in crystals.

Prep. By acting on the native carbonate of baryta (Witherite) by means of hydrochloric acid assisted by heat.

Prop. & Comp. Flat rectangular, white, transparent crystals with bevelled edges; taste acrid and disagreeable; pretty soluble in water. Composition of crystals (Ba Cl + 2 HO).

Off. Prep. Solution of Chloride of Barium. Appendix B. (Chloride of Barium in crystals, one ounce; distilled water to ten fluid ounces.)

Use. Chloride of barium is introduced into the Pharmacopoeia as a test for detecting the presence of sulphuric acid or sulphates in solution; the precipitated sulphate of baryta forms a heavy white powder, insoluble even in boiling nitric acid.

Therapeutics. Chloride of barium has been employed in medicine, and in small doses appears to act as an alterative, especially, affecting the glandular system; it is also supposed to act on the nervous centres. It is, however, a very poisonous salt, and is seldom used therapeutically.

Pose. 1/2 gr. to 2 gr. and upwards.