Characters. - Solid, greenish fragments, liver-brown when recently broken, alkaline, and acrid to the taste.

Solubility and Reactions. - It readily forms with water a yellow solution, which has the odour of sulphuretted hydrogen, and evolves it freely when excess of hydrochloric acid is dropped into it, sulphur being at the same time deposited. The acid fluid when boiled and filtered is precipitated yellow by perchloride of platinum, and white by chloride of barium.

Impurity. - Carbonate left in the preparation, or sulphate formed by decomposition.

Test. - About three-fourths of its weight are dissolved by rectified spirit, in which both carbonate and sulphate are insoluble.

Dose. - 2 to 10 grains.

Prepakation.

B.P

Unguentum Potassae Sulphuratae (5 parts, hard paraffin 18, soft paraffin 55).

Action. - When applied to the skin, the ointment may be used instead of simple sulphur ointment. In the intestine sulphurated potash seems to stimulate peristaltic action, and to act as a laxative. Apparently also, like sulphur, it has a somewhat stimulating action upon the respiratory mucous membrane, and upon the sweat-glands.

Uses. - The ointment is used externally in cases of scabies and acne. Sulphurated potash is used as a bath in chronic rheumatism (p. 470), rheumatoid arthritis, and chronic organic nerve-disease, and as a diaphoretic in albuminuria. It has been given internally in chronic bronchitis, croup, and whooping-cough, and used as an injection into the rectum to destroy ascarides, in solutions of half a grain to a grain in the ounce of water.