In its Photographic application, the nitrate of silver is the most valuable
of the salts of that metal, as from it most of the other argentine compounds
can be prepared, although it is not of itself sufficiently sensible to light
to render it of much use.

CHLORIDE OF SILVER.--This salt of silver, whether in its
precipitated state, or when fused, changes its color to a fine
bluish grey by a very short exposure to the sun's rays.
If combined with a small quantity of nitrate, the change is
more rapid, it attains a deep brown, then slowly passes into
a fine olive, and eventually, after a few weeks, the metalic
silver is seen to be revived on the surface of the salt.
Great differences of color are produced on chlorides of silver
precipitated by different muriates. Nearly every variety
in combination with the nitrate, becomes at last of the same
olive color, the following examples, therefore, have reference
to a few minutes exposure, only, to good sunshine; it must
also be recollected that the chloride of silver in these cases
is contaminated with the precipitant.

Muriate of ammonia precipitates chloride to darken to a fine
chocolate brown, whilst muriate of lime produces a brick-red color.
Muriates of potash and soda afford a precipitate, which darkens
speedly to a pure dark brown, and muriatic acid, or aqueous chlorine,
do not appear to increase the darkening power beyond the lilac
to which the pure chloride of silver changes by exposure.
This difference of color appears to be owing to the admixture
of the earth or alkali used with the silver salt.