By this
means, the author obtained impressions instantaneously in the sunshine,
and in five to ten seconds in a moderate light; and he hopes to be able
to take moving objects. It can be applied by exposing the prepared
plate over a surface of water, to which a few drops of ammonia have
been added (sufficient to make it smell of ammonia); or the vapor can
be introduced into the camera during the action. In fact, the presence
of ammonia, in the operating-room, appears to have a good effect, as it
also neutralizes the vapors of iodine and bromine that may be floating
about, and which are so detrimental to the influences of light upon the
plate."

GALVANIZING THE DAGUERREOTYPE PLATE.

In consideration of the importance of galvanized plates, I shall
endeavor to give as plain and concise a manner of manipulation as
possible. For some time it was a question among the operators
generally, as to the beneficial result of electrotyping, the
Daguerreotype plate, but for a few years past our first operators have
found it a fact, that a well electro-silvered surface is the best for
producing a portrait by the Daguerreotype.

From my own experiments, I have found that a plate, by being
galvanized, can be rendered more sensitive to the operation of the
light in proportion of one to five, viz.: if a plate as furnished by
the market, be cleaned, polished, coated and exposed in the camera, if
the required time to freely develop an impression be ten seconds, a
similar plate prepared in like manner and galvanized, will produce an
equally well-defined image in eight seconds. In connection with this
subject, there is one fact worthy of notice; a plate with a very heavy
coating of pure silver, will not produce an equally developed image, as
a plate with a thinner coating, hence the thin coating, providing it
entirely covers the surface, is the best, and is the one most to be
desired. The experiment is plain and simple. Let the slate receive a
heavy or thick coating by the electrotype, then polish, coat, expose in
the usual manner, and the result will be a flat, ashy, indistinct
impression; when, on the other hand, the thin coating will produce a
bright, clear and distinct image, with all the details delineated.

The style of battery best for the purpose has been, and now is, a
question of dispute among operators; some preferring the Daniell
battery to Smee's. Some claim the superiority of the first from its
uniformity of action;