Present name. - Potassic Sulphate. K2So4.

This may be obtained from the operative chemists.

Characters and Tests. - In colourless hard six-sided prisms terminated by six-sided pyramids; decrepitates strongly when heated; sparingly soluble in water, insoluble in alcohol. The aqueous solution is neutral to test-paper, gives no precipitate with Oxalate of Ammonia, but acidulated with Hydrochloric Acid, it is precipitated white by Chloride of Barium, and yellow by Perchloride of Platinum.

A short notice of this occurs in Brit. Journ. of Horn., vol. xi.

Preparation. - Trituration.