Isinglass. Isinglass is a preparation formerly made only from the great Sturgeon ; but is now obtained from the entrails of most other fishes. When good, it consists almost wholly of pure gelatine, or glue, which is nutritious. It is free from taste and smell, and is soluble in warm water. Being nothing more than the membraneous parts of fishes, it can probably be made from the fish on the coasts in this country. The sounds or air-bladders of fresh-water fish are generally preserved for this purpose, and it is best made in the warm season. It is sometimes used as a medicine; but boiled in milk it forms a nutritious jelly, and is the substance of blancmange. It is also used for refining coffee, vinous liquors, and cider.