dried.

The image thus obtained can hardly be distinguished from silver prints;
the tone is soft, brilliant and permanent.

This process is quite original and interesting. The theory is as follows:
Under the action of light the ferric oxalate is reduced in the ferrous
salt, insoluble, which, after the print has been cleared from the ferric
oxalate, is oxidized and reduced into ferric oxide by the alkalized
permanganate, the latter then forming colored compounds with reagents.

It has been lately published in England under the name of "kallitype," a
new process--or old, ad libitum--which consists in developing the image in
ferrous oxalate by a peculiar silver compound whose formula is given
below. The paper is prepared by brushing with a strong solution of
neutral ferric oxalate dried rapidly--which is a sine qua non when using
deliquescent salts; and after exposure the image is developed, etc.

Silver nitrate 50 grains
Sodium citrate 800 grains
Potassium bichromate 1 to 2 grains
Water 10 ounces

"Dissolve the silver nitrate in 1 ounce of water, the citrate and
bichromate in the remainder and mix. The precipitate--silver citrate and
chromate--is then dissolved by adding 1 dram of ammonia .880, and after 35
drops of strong nitric acid has been added the solution is ready for use."

This process reminds us that of Robert Hunt (1842), and that of more
recent date (1863), of Borlinetto, who developed the image in black with a
silver nitrate alcoholic solution, 1:500, and after washing the picture in
a solution of citric acid, 1:10, fixed it by aqueous ammonia. But,
although that is not absolutely necessary, we would advise one working
this, or similar processes in which a silver salt is employed for
developing, to fix the image, after treatment with citric acid to clear
the proofs from iron salts, in a solution of ammonium sulphocyanate--which
has not the injurious effect of sodium thiosulphate (hyposulphite)--in
order to prevent the paper to be tinged by the reduction of the silver
nitrate which is mechanically retained in its fiber.

The solution of ammonium sulphocyanate should be compounded with auric
chloride to tone the picture at the same time it is fixed; thus:

Ammonium sulphocyanate 35 parts
Gold terchloride 0.15 part
Water 350 parts

The solution can be used over again.

In the processes devised by Dr. Phipson, Monckhoven and othe