Present name. - Sodic Sulphite. Na2So3,10H1O.

May be obtained from the operative chemists.

Characters and Tests. - Efflorescent, oblique prisms, which fuse at 113° and impart a yellow colour to flame. Soluble in about 4 parts of cold water: the solution has a slightly alkaline reaction and a sulphurous taste. On the addition of dilute Hydrochloric Acid, it evolves a pungent odour of Sulphurous Acid, at the same time remaining clear, no separation of Sulphur taking place.

Preparations. - Trituration. Solution in distilled water.