a white crystalline double salt, sodium potassium tartrate, used in Seidlitz powder. Formula: KNaC4H4O6.4H2O
Word origin
C18: named after La Rochelle, French port
Rochelle salt in American English
(roʊˈʃɛl)
a colorless crystalline compound, potassium sodium tartrate, KNaC4H4O6·4H2O, used as a laxative, in baking powders, and, in electronics, as a piezoelectric material