lution containing six ounces of water and half an
ounce of each pure carbonate of potash, alum, common salt, gallic acid,
sulphate of copper, and purified borax. While the plate is wet, pour
on a little, and heat it with a powerful blaze. The effect will be
quickly produced, in from three to fifteen seconds. Rinse and dry, as
in the gilding.

Bleaching Solution.--Make a saturated solution of muriate of ammonia
(sal ammoniac) in pure water, and filter through paper. Reduce with an
equal quantity of water when used. When the linen or any other portion
of the impression is badly solarized, after removing the coating, rinse
with water; then pour this upon the surface in the same manner as the
gilding solution. If the solarization be very deep, apply the lamp
beneath, and warm the plate a trifle. Now pour off, and, without
rinsing, apply the gilding. The whole operation must be quickly
performed, or the chlorine soon attacks the shades of the picture.
When properly done, however, the solarized parts are restored to a
clear, transparent white.

Electro, or Cold Gilding.--This process I have adopted, and it produces
exceedingly beautiful impressions for the stereoscope, adding a great
charm to the pleasing effect of that instrument. It also possesses a
pretty and curious effect on views. It is easy of trial, and may be
used by dissolving one gramme of chloride of gold in half a litre of
ordinary water, and thirty grammes of hyposulphite of soda in another
half litre of similar water; then pour the solution of chloride of gold
into that of soda, by little and little, agitating it exactly as in M.
Fizeau's preparation, of which there is but a variation.

When you wish to use it, pour some into a plate, or any other vessel of
the same kind, sufficient to cover the proof; then, after having added
to it a drop of ammonia, immerse the plate in it as soon as you take it
out of the mercury-box, after having wiped its back and edges, and
agitate the mixture quickly from right to left, so as to dissolve
rapidly the coating of iodide of silver as usual. As soon as the plate
appears white, cease all rapid motion, but continue to give it a slight
undulating one; for if it were allowed to remain still for only a few
minutes, the proof would be clouded. By little and little, the surface
of the plate takes a yellow tint, which darkens more and more,
approaching to bistre. You stop therefore, at the color you wish; and
when the