or lady's handkerchief, a piece of dark cloth (a temporary bosom
of nankeen is best,) may be put over it, but quickly withdrawn
when the process is about two thirds finished.

A very pleasing effect is given to portraits, by introducing,
behind the sitter, an engraving or other picture--if a painting,
avoid those in which warm and glowing tints predominate.
The subject of these pictures may be applicable to the taste
or occupation of the person whose portrait you are taking.
This adds much to the interest of the picture, which is otherwise
frequently dull, cold and inanimate.

Mr. J. H. Whitehurst of Richmond, Va., has introduced a revolving
background, which is set in motion during the operation, and produces
a distinctness and boldness in the image not otherwise to be obtained.
The effect upon the background of the plate is equally pleasing;
it having the appearance of a beautifully clouded sky.

In practising Photographic drawing on paper, the student
must bear in mind that it is positively essential, to secure
success in the various processes, to use the utmost precaution
in spreading the solutions, and washes from the combination
of which the sensitive surfaces result. The same brush should
always be used for the same solution, and never used for any other,
and always washed in clean water after having been employed.
Any metalic mounting on the brushes should be avoided,
as the metal precipitates the silver from its solution.
The brushes should be made of camels or badger's hair and sufficiently
broad and large to cover the paper in two or three sweeps;
for if small ones be employed, many strokes must be given,