Also found in: Dictionary, Thesaurus, Medical.
Seignette salt:see Rochelle saltRochelle salt,
colorless to blue-white orthorhombic crystalline salt with a saline, cooling taste. It is also called Seignette salt after Pierre Seignette, an apothecary of La Rochelle, France, who was the first to make it (c.1675).
..... Click the link for more information. .
(also Rochelle salt, potassium sodium tartrate), a binary salt of the tartaric acid KOOC-(CHOH)2COONa 4H2O. It is named after the French apothecary P. Seignette (1632–98), who discovered the salt in 1655.
The salt’s colorless crystals decompose at 55.6°C and are freely soluble in water (1,390 grams per liter at 30°C). The name for a class of substances with unique dielectric properties, first discovered (Valasek, 1920) in this salt, is derived from the term “Seignette salt.” Seignette salt is contained in Fehling’s reagent (reactive with aldehydes and ketones) and is used as a laxative.