Alan is %100 right! Shvartztumah (meaning black impurity) is the Yiddish name for Belaya Tserkov - which probably has some very Christian religious meaning. In Hebrew it was called "Sdei Lavon" as in "White Field", a more positive but perhaps sarcastic translation of the Yiddish. It was the home to great Chasidic masters and is often mentioned in Classic Chasidic works.
