rfaces, first rub
the surface with a mixture of muriatic acid and alcohol, then apply the
label with a very thin coating of the paste, and it will adhere almost as
well as on glass. 5. To make cement for attaching labels to metals, take
10 parts tragacanth mucilage, 10 parts of honey, and 1 part flour. The
flour appears to hasten the drying, and renders it less susceptible to
damp.

A COLORLESS CEMENT FOR JOINING SHEETS OF MICA.

A colorless cement for joining sheets of mica is prepared as
follows:--Clear gelatine softened by soaking it in a little cold water,
and the excess of water pressed out by gently squeezing it in a cloth. It
is then heated over a water bath until it begins to melt, and just enough
hot proof spirit (not in excess) stirred in to make it fluid. To each pint
of this solution is gradually added, while stirring, one-fourth ounce of
sal-ammoniac and one and one-third ounces of gum mastic, previously
dissolved in four ounces of rectified spirits. It must be warmed to
liquefy it for use, and kept in stoppered bottles when not required. This
cement, when properly prepared, resists cold water.

A CEMENT THAT WILL RESIST THE DAMP.

A cement that will resist the damp, but will not adhere if the surface is
greasy, is made by boiling together 2 parts shellac, 1 part borax, and 16
parts water.

TO MAKE GLUE WATERPROOF.

The best substance is bichromate of potash. Add about one part of it,
first dissolved in water, to every thirty or forty parts of glue; but you
must keep the mixture in the dark, as light makes it insoluble. When you
have glued your substances together, expose the joint to the light, and
every part of the glue thus exposed will become insoluble, and therefore
waterproof. If the substances glued together are translucent like paper,
all will become waterproof; if opaque like wood, only the exposed edges
will become so, but they also protect the interior--not exposed
parts--against the penetration of moisture.

TWO GLUE RECIPES.

A glue ready for use is made by adding to any quantity of glue, common
whisky, instead of water. Put both together in a bottle, cork it tight and
set it for three or four days, when it will be fit for use without the
application of heat. Glue thus prepared will keep for years, and is at all
times fit for use, except in very cold weather, when it should be set in
warm water before using. To obviate the difficulty of the stopper getting
tight by the glue dr