Characters. - Minute, colourless, or white monoclinic crystals, or a crystalline powder, deliquescent on exposure to air, odourless, having a saline and slightly bitter taste and a neutral or faintly alkaline reaction.

Solubility. - Soluble in 0.6 part of water and in 1.8 parts of alcohol at 15° C. (59° F.).

Reaction. - If disulphide of carbon be poured into a solution of the salt, then chlorine water added drop by drop, and the whole agitated, the disulphide of carbon will acquire a violet colour.

Dose. - 3 to 30 grains.

Uses. - It is employed in place of iodide of potassium. Its physiological actions are almost exactly the same, but it appears to be less depressing and to irritate the stomach less. It may thus be given in larger doses.