Emily Dickinson Lexicon

I'SIN-GLASS, n. [i'zinglass. that is, ise- or ice-glass.]

A substance consisting chiefly of gelatin, of a firm texture and whitish color, prepared from the sounds or air-bladders of certain fresh-water fishes, particularly of the huso, a fish of the sturgeon kind, found in the rivers of Russia. It is used as an agglutinant, and in fining wines. Encyc.