- isinglass (n.)
- purest commercial form of gelatin, 1520s, apparently a perversion of Dutch huysenblas, literally "sturgeon bladder," from huysen "sturgeon" + blas "bladder," from PRoto-Germanic *bles-, extended form of root *bhle- (2) "to blow, swell" (see bole). So called because the substance was obtained from the air-bladders of certain freshwater fishes.
