The Probert Encyclopaedia of Science & Technology

GELATINE

Gelatine is a concrete animal substance, transparent, and soluble slowly in cold water, but rapidly in warm water. It is confined to the solid parts of the body, such as tendons, ligaments, cartilages, and bones, and exists nearly pure in the skin, but it is not contained in any healthy animal fluid. Its leading character is the formation of a tremulous jelly when its solution in boiling water cools.

Gelatine does not exist as such in the animal tissues, but is formed by the action of boiling water. The coarser forms of gelatine from hoofs, hides, etc, are called glue; that from skin and finer membranes is called size; and the purest gelatine, from the air-bladders and other membranes of fish, is called isinglass. With tannin a yellowish white precipitate is thrown down from a solution of gelatine, which forms an elastic adhesive mass, not unlike vegetable gluten, and is a compound of tannin and gelatine. It is this action of tannin on gelatine that is the foundation of the art of tanning leather.

Gelatine when acted upon by sulphuric acid yields gelatine sugar or glycocoll. When treated with potash it is said to yield glycocoll and leucine. Gelatine is nearly related to the proteids.
Research Gelatine