admit of a greater degree of intensity, it might be heated anew;
but that is seldom necessary, and often by trying to do too,
well, the operator, if he persists in heating certain parts
of the plate, may find the liquid dry up just above the flame,
and inevitably cause a stain*; or else the blacks are covered
with a film, or even the coating of gold may suddenly exfoliate,
when small particles are detached from the plate.
The impression is then entirely spoiled, but the plate
may be re-polished.

* This can be remedied, however, if it is immediately
washed over with the same solution that is on the plate,
so that the surface shall not become cool; continue for a short
time to apply the lamp under, and agitate the plate slightly,
and it will soon be free from all imperfections and give
a fine clear tone.

It is not unfrequent that the surface assumes a dark, cloudy appearance.
This is generally the best sign that the gilding will bring
out the impression with the greatest degree of distinctness.
Soon, the clouds gradually begin to disappear, and, "like a thing
of life" stands forth the image, clothed with all the brilliancy
and clearness that the combined efforts of nature and art can produce.
When in the operator's judgment the operation has arrived at the highest
state of perfection, rinse suddenly, with an abundance of clean water,
and dry as before described.

When an impression is dark, the gilding process may be longer continued;
but when light, it should be gilded quickly, as lengthening
the time tends to bleach the impression and make it too white.