If the operator should allow the hyposulphite solution to run
over the plate unevenly, it is quite likely that white or blue
streaks would result. These it is impossible to remove without
injury to the impression. Some, in order to prevent this,
breathe over the surface, thus moistening it and putting it
in a condition to receive the solution with greater uniformity.
The plate should be well washed with water before gilding.

Gilding, or Fixing the Image.--The next process to be given is that for fixing
the image on the plate. This is done by precipitating a thin film of gold
over the surface and is productive of the most brilliant effect when prepared
immediately after the plate has been washed with water after the application
of the hyposulphite solution, and before the plate has been allowed to dry.
When, however, the plate has been dried and allowed to stand for any time,
before gilding, the hyposulphite wash should be applied as at first,
in order to destroy any chemical coating that may have been formed on exposure
of the plate to the air. For gilding the larger plates, we have a gilding
stand so constructed that the plate can be put on a perfect level.
In practice, I prefer holding the plate with nippers, fastened at one corner.
Hold the plate in the same manner as in removing the coating;
pour on the gilding, newly filtered, until the surface is wholly covered,
and with the blaze of the spirit lamp, at least three inches high, apply it
to the back of the plate, moving it about, that the surface may be heated
with as much uniformity as possible. Continuing this operation, the surface
will generally become covered with small yellow bubbles which soon disappear,
leaving the image clear and distinct.

It is advisable to make use of a lamp having a sufficiently
strong flame to produce the effect in a few minutes.
If after a first heating, it is found that the impression can