Present name. - Potassic Tartrate. K2C4H4O6.
Prepared by neutralizing Cream of Tartar with Carbonate of Potash and crystallizing.
Characters and Tests. - In small colourless four- or six-sided prisms. Heated with Sulphuric Acid, it forms a black tarry fluid, evolving inflammable gas and the odour of burned sugar. Acetic Acid added sparingly to its solution causes the separation of a white crystalline precipitate. Entirely dissolved by its own weight of water. 113 grains heated to redness till gases cease to be evolved, leave an alkaline residue, which requires for exact neutralization 1,000 grain measures of the volumetric solution of Oxalic Acid.
A short notice of this occurs in Brit. Journ. of Horn., vol. xi.
Preparations. - Trituration. Solution in distilled water.