as one recommendation of this
process to ladies and other lovers of clean hands, that any brown stains
left by it on the fingers or elsewhere are at once removable by a little
weak ammonia or soap and water. * * * I would particularly suggest, as
deserving of notice, the development of the salts of sesquioxide of
uranium, and still more iron, by the metals and metallic-cyanic alkaline
salts, as also by the mellonides and nitro-prussides, and the latter also
by itself and as developed by many metallic salts."

"I have since had the opportunity of trying the nitro-prusside of sodium,
which, by itself, gives a blue and white picture, in color like that
obtained from the red prussiate of potash."

"When mixed with a solution of ammonio-nitrate of copper, previous to its
application to the paper, the color obtained is pale purplish pink or
peach-blossom color. By mixing it in the same way with ammonio-oxalate of
sesquioxide of iron, we get a dull green picture, changeable through
intermediate stages into brown by alkaline carbonates, and that into a
_dirty_ black by gallic acid. It may be well to know that the blue of the
picture given by the red prussiate in the process of Sir John Herschel may
be considerably modified or entirely changed to another color, in many
ways, without interfering with the purity of the white ground, by steeping
the picture, after the undecomposed red prussiate has been washed out, in
solution of salts of various metals, copper, uranium or cobalt, for
instance, and that the colors so produced may be modified as desired,
according to the stage at which the action is stopped."

"There remains but one class of uranic photographs to be described,
namely, that obtained when we develop with a salt of silver or gold (or
platinum?). This class may be made to print much more rapidly than our
ordinary silver printing process, approaching sometimes more nearly to the
calotype development in this respect. We get the _minutest details_ with
great fidelity, and the picture is effectually fixed by a simple fresh
hyposulphite solution, with a good color in many cases, or by ammonia,
which will be considered an advantage by those who hold the hyposulphite
an enemy to durability. Different shades of color are produced according
to different solvent acids and different details. I have got a good black
perfectly like that of an engraving, by the nitrate of uranic oxide,
developed by ammonio-nitrate of silver (o