(From the Paper World.)

To Render Glue Waterproof, first soak it in water till it becomes soft, and then melt it with gentle heat in linseed oil.

A Marking Ink for Wooden Packages.—Dissolve asphalt in naphtha or turpentine to a thin fluid. This dries quickly, and the markings are nearly indestructible.

To Take Grease Stains out of Paper.—Apply pipeclay, powdered and mixed with water to the thickness of cream; leave it on for four hours.

To Take Dirt off Book Leaves without injuring the printing: Besides the ordinary use of bread-crumbs, for the removal of stains, a solution of oxalic acid, citric acid, or tartaric acid may be used. These acids do not attack printing ink, but will remove marginal notes in writing ink, &c.

To Toughen Paper.—To render paper as tough as wood or leather, combine chloride of zinc with the pulp in the course of manufacture. The greater the degree of concentration of the zinc solution, the greater will be the toughness of the paper, which is thus serviceable for making boxes, combs, &c.