GLUE, an inspissated jelly, of a tenacious nature, employed by artificers as a cement. It is made from various substances, according to the uses to which it is to be applied, but most commonly by boiling the parings of hides and other offals in water, and then straining the viscous matter through a wicker basket, and suffering the impurities to subside, after which process it is again boiled. Common glue is made of the skins of animals, such as oxen, cows, sheep, and the like. The parings are first digested in hot water, to remove grease and dirt from them; they are then steeped in water, and stirred from time to time; lastly, they are piled in a heap to allow of the water being pressed out, and then put into the boiler. The water is generally kept near to a boiling heat, without being suffered to enter into ebullition. When sufficiently thick, the glue is poured into flat frames or moulds; and when congealed it is cut up into square pieces, and afterwards dried in a coarse net. Glue improves by age, and that is considered as the best which, if steeped in water three or four days, swells without melting, and resumes its former consistency after being dried. A transparent and beautiful glue is made of the shreds and parings of vellum, parchment, or white leather.