others, of the latter, for its strength. I
consider either good, and for the inexperienced would prefer the
Daniell. This is more simple in its construction, while it has
certainty in action. The more skillful electrotyper would prefer
Smee's, and this is the one most generally in use. I would remark that
the plan of galvanizing plates should be followed by every operator,
and when once thoroughly tested, no one will abandon it.

SILVERING SOLUTION.

To any desired quantity of chloride of silver in water add, little by
little, cyanide of potassium, shaking well at each addition, until all
the cyanide is dissolved. Continue this operation, and add the
cyanide, until all the precipitate is taken up and held in solution.

This solution is now ready for the plate-cup. Enough water may be added
to cover any sized plate when held perpendicular in the cup. The
strength of the solution may be kept up by occasionally adding the
chloride of silver and cyanide of potassium. There should alway be a
very little excess of the cyanide.

The plate should be well cleaned and buffed, and the solution well
stirred before it is immersed. Care should be observed to keep the
solution clean, and allow no particle of dust to come in contact with
the surface of the plate. The plate is now to be attached to the pole
of the battery.

After remaining a short time, it assumes a blue color; take it out,
rinse freely with pure water, then dry with a spirit lamp, and it is
ready for buffing. Buff and coat in the usual manner. Some operators
are in the practice of immersing the plate in the solution and buffing
twice. This additional silvering is no improvement wherever there has
been a proper first coating.

Sometimes the operator is troubled with streaks or scum on the plate.
This may arise from three causes, all of which experience must teach
the experimenter to avoid; first, too great an excess of cyanide in the
solution; second, a lack of silver; third, the current too strong.
Another annoyance arises from the solution being dirty and the dirt
collecting on the surface. When this is the case, the dirt is sure to
come in contact with the surface of the plate as it is plunged into the
solution, and the result is a scum that it is difficult to dispose of.
This can be prevented only by frequent filtering. One thing should
always be borne in mind in electrotyping Daguerreotype plates--that in
order to secure a perfectly coated su