The following is a good cement for celluloid. Shellac 1 part, dissolved in 1 part of spirit of camphor and 3 to 4 parts of 90-percent, alcohol. This should be applied warm, the broken parts being held together securely till the solvent has evaporated. A cement for ebonite is merely a marine glue which can be made as follows. Dissolve pure india-rubber in naphtha by means of heat, then add 2 parts of shellac to 1 part of indiarubber; continue heating till the whole is melted. Whilst hot, pour the mixture on metal plates to cool. When using, remelt it, and apply hot, at the same time warming the articles to be joined. Squeeze the glue well out when making the joint. A cement that will stick xylonite or ebonite together may be made by dissolving pyroxylin (collodion cotton) in acetone or camphorated spirit to the thickness of cream. To make a cement for joining celluloid, etc., to gold or other metal, dissolve five or six pieces of gum mastic, each as big as a large pea, in as much alcohol as is required to make them liquid. Soften about 1/2oz. of isinglass in water; wipe it dry when it becomes pliable, then dissolve it in strong brandy or rum, making enough strong glue to fill a 2-oz. bottle.

A small piece of gum ammoniac or gnlbanum is next added, and stirred about till dissolved; pounding in a mortar would assist this. Heat is necessary to render the cement fluid. Another recipe is: Soak 1 oz. of isinglass till it absorbs 3 oz. of water, andaddloz. of spirit of wine (85-per-cent. alcohol). Dissolve as much gum mastic as 4 oz. of alcohol will take up, and add it to the isinglass solution. Powder 2dr. of gum ammoniac, and mix it with the rest. The whole may be ground up with pestle and mortar if done quickly, so that the alcohol does not evaporate. Keep the cement in closely corked bottles, and heat it when about to use. To cement xylonite, etc., to glass, use either of the following. (1) Dissolve 2 parts of white shellac and 1 part of Venice turpentine in 7 parts of methylated spirit, and pour off the clear liquid. (2) Heat Canada balsam on a stove until it is hard, then dissolve 1 part in 3 or 4 parts of benzine. Apply to the xylonite and allow to dry on, then moisten with a little of the warm solvent employed in making, and press to the glass.

Lip glue (that is, a mixture of glue size and sugar) might be used, but it would give way if exposed to damp.