Glue And Gelatlne is the animal matter contained in bones, sinews, hide and similar substances, of animal origin. It is procured by boiling out the glue forming substances with the aid of water, or by dissolving, in the case of bone, the mineral matter with acid and further dissolving the residual gluey matter. These watery solutions of glue are evaporated to free the glue from moisture, as far as possible, without injury. The concentrated solution is run into moulds, cooled, cut into thin strips and dried. The cheap glue ground and in flake form is bone and offal glue made by simply boiling with water to dissolve out the glue, with the final treatment before mentioned. Such glues have, usually, very little strength. The stronger glues and gelatines are those made from hide, or gelatine glue made from bone by the acid dissolving process.

For any purpose whatever, good glue or gelatine should be used, for, while cheap glue will sometimes scarcely geletanize in 10 parts of water, good glues may geletanize in 30 to 50 parts of water. The white, or opaque glues owe their color to the introduction of zinc, barytes, or some like substance to whiten them. They rather detract, than add to the value.

Isinglass is that form of gelatine made from fish bladders.