| Colophonium (resin) | 100 |
| Common soap | 100 |
| Tar | 50 |
| Whale-oil | 25 |
Smear the trunks of the trees with this. It may also be put on sheets of brown paper to catch flies.
Cement for Filling.—Take fresh curd (caseine), and knead it with water to a putty. It can be used in this state for many purposes. To greatly harden it, add one-twentieth of its weight in lime, and more or less of some indifferent substance, such as chalk, calcined magnesia, oxide of zinc, and colouring matter. This sets so hard that it may be used to make casts or many small works of art.
French Glues.—Two very excellent glues used in France are the colle forte de Flandre and that of Givet. Goupil recommends as the best glue, where a very superior article is required, one made of equal parts of the two. Break them up, let the pieces remain fifteen hours in water, then boil for two hours in the bain-marie, or glue-kettle. After a time the glue will settle and become clear. Add, if needed, a little water from the bain-marie.
To give a Satin Gloss to Paper.—Paint with a broad, soft brush on the paper with a solution of hypo-sulphite of barium (chemically expressed by BaS2O3). It may be laid on by itself or mingled with a colour. It is used sometimes by bookbinders. This may be applied in water-colour pictures to the imitation of silk or satin.
Gomme laque, or shellac, also gelatine glue, is sold in thin leaves. To prepare it, put into a bain-marie twenty parts of the gum to one of flowers of sulphur, stir it well, and add a little lukewarm water. It may be made into little bars by hand; let them cool, and warm them when required for use.
A very good cement, which, according to Fred. Dillaye, is both fire and water proof, is made as follows:—Take half-a-pint of milk, as much vinegar, mix them, and take away the whey. Add the white of five eggs to the curd, mix the whole well, and add so much finely sifted quicklime as will form a paste.
Snail Cement.—It is said that snails or slugs, mashed, form a strong and hard glue. This is probable; also, that it would combine with powdered quicklime, or carbonate of lime in powder, to set very hard.
To mend marble use shellac in leaves, mixed with white wax.
To mend alabaster use gum-arabic mixed with powdered alabaster. This is also useful for many other purposes.