till it takes a nice green
color. The blue color is then obtained by applying on the parchment thus
prepared a solution of carbonate of potash. Use two ounces for one gallon
of water. Another method is to cover it by means of a brush with
aquafortis, in which copper dust has been dissolved. The potash solution
is then applied as before, till the required shade is obtained. Another
method is by using the following solution:--Indigo, 5 ozs.; white wood,
10 ozs.; alum, 1 oz.; water, 50 ozs. Red:--The parchment is dyed red by
applying with a brush a cold logwood solution, and then using a 3 per cent
potash solution.

TO MAKE PAPER FIRE AND WATER-PROOF.

To make paper fire and water-proof, mix two-thirds ordinary paper-pulp
with one-third asbestos. Steep in a solution of common salt and alum, and
after being made into paper coat with an alcoholic solution of shellac. By
plunging a sheet of paper into an ammoniacal solution of copper for an
instant, then passing it between the cylinders and drying it, it is
rendered entirely impermeable to water, and may even be boiled without
disintegrating. Two, three, or any number of sheets rolled together become
permanently adherent, and form a material having the strength of wood. By
the interposition of cloth or any kind of fiber between the layers, the
strength is greatly increased.

A NEW BLOTTING PAPER.

A blotting paper that will not only dry the blot, but bleach the remainder
of it can be made by passing ordinary blotting paper or card through a
concentrated solution of oxalic acid. Care must be taken that no crystals
appear, which would injure the porosity of the paper.

IMPERMEABLE PAPER.

To make impermeable paper, prepare the two following baths: (1) alum, 25
ozs.; white soap, 12-1/2 ozs.; water, 100 ozs. (2) gum arabic, 6 ozs.;
Colle de Flandre, 18 ozs.; water, 100 ozs. Place the sheet of paper in the
first bath to be well impregnated. In this bath the paper is left only for
a short time. It is then dried and dipped in the second bath, the same
precautions being used as for the first bath. When dry, the paper is
hot-pressed in order to render it uniform.

TO MOUNT CHROMOS FOR FRAMING.

To mount chromos for framing, first soak for fifteen minutes in a shallow
dish, or lay between two newspapers that have been thoroughly saturated
with water; then paste to the panel of the wood or canvas which has been
prepared to receive them. Care must be taken that there ar