Tartrates, salts formed by the union of tartaric acid with bases. Tartaric acid is dibasic, and forms with monatomic metals acid salts, like bitartrate of potassium, KHC4H4O6; normal salts, like normal potassic tartrate (soluble tartar), K2C4H4O6; and double salts, like sodic-potassic tartrate (Rochelle salt), NaKC4-H406. With diatomic metals it forms normal salts, like normal basic tartrate, BaC4H406, and double salts consisting of a double molecule of the acid in which two atoms of hydrogen are replaced by a diatomic and two atoms by a monatomic metal, like baric-potassic tartrate, BaC4H406,K2C4H406 + 2H3.O With tri-atomic metals it forms a peculiar class of salts, well illustrated in the case of the antimony salts, as normal antimonious tartrate, (SbO)2 C4H4O6; acid antimonious tartrate, SbO,C4H5 06; and potassio-antimonious tartrate, tartar emetic, KSbOC4H406;. Many of the tartrates are used in medicine, and several are employed in calico printing and dyeing, as the tartrate of chromium and the tartrate of potassium and tin.

The principal medicinal tartrates are the double salts, tartar emetic and Rochelle salt. (See Antimony, and Rochelle Salt.) The tartrates of the alkalies are oxidized in the animal system to bicarbonates, so that the administration of tartrate of potassium renders the urine alkaline. The acid alone, on the other hand, is more efficient than the mineral acids in acidifying this excretion.