ened, it is only necessary
to add a little of the sulphate of copper.

"With the battery prepared as above, and the solution of sulphate of
copper in a vessel of proper dimensions to receive your plate, connect
the galvanic current, and immerse the impressioned plate, letting it
remain until a thin film of copper has been formed, then the battery
can be strengthened, and the impression will be of sufficient thickness
to be removed in from eight to twelve hours. An old Daguerreotype
plate attached to the opposite pole of the battery (copper side towards
the face of the plate to be electrotyped), will answer the same purpose
as the silver-plate.

"The great difficulty in taking an electrotype impression, and
preserving the original, has been attributed to the battery being too
powerful. I am led to believe from practice that the principal
difficulty has been in the Daguerreotype plate itself, for if we use an
impression that has been taken but a few days, and taken in the usual
way, we will find it difficult to succeed without spoiling both the
copy and original, and so also with an old impression.

"I have found the most certain method to be as follows:--Coat the
Daguerreotype plate as usual, except use less of the accelerators, the
proportion of iodine coating being greater, of course the time of
exposure in the camera will be lengthened. Mercurialize it at about a
temperature requiring to develop the image, from six to eight minutes,
at least. Gilding the Daguerreotype has much to do towards producing a
good electrotype copy. This should be done by applying a little heat,
and gilding very slowly, giving a coating of gold with the greatest
possible uniformity. By this method, I have been enabled to produce
any number of proofs. I have produced a dozen from one impression, and
it remains as perfect as when first taken.

"By a little judgment and care the operator will be enabled to produce
the electrotype copy of the Daguerreotype plate without any difficulty.
The electrotype copy should be immediately put under a glass and sealed
in the same manner as the ordinary Daguerreotype."

CRAYON DAGUERREOTYPES.

This process is patented in the United States, by J. A. Whipple, of
Boston, and of course no honorable person will use it for his own
benefit without purchasing a right.

A white back-ground is generally employed, the object being to blur the
lower portion of the plate, leaving the head of the subject i