Any questions in regard to photograph matters will be willingly answered by the Editor of this column, and we should be glad to hear from any of our club who can make helpful suggestions.
THE KALLITYPE PRINTING PROCESS.
The kallitype printing process was invented and patented by Dr. Nichol of England, professor of chemistry in Mason College. The name "kallitype" is often confounded with "calotype," the name which Talbot gave to his paper negative process, patented in 1841. Both names are derived from the same Greek words meaning "beautiful picture." Kallitype paper is coated with two iron salts—ferric oxalate and ferric nitrate—and with silver oxalate and silver nitrate. The action of light on the ferric oxalate is to reduce it to ferrous oxalate. This paper is not a printing-out paper, but must be developed. A developing solution is prepared as follows:
| Rochelle-salt | 1 | oz. |
| Borax | ¾ | oz. |
| Water (filtered) | 10 | oz. |
Make up a solution of 20 grains of bichromate of potash and 1 oz. of water, and another solution of four drachms of ammonia to 1 quart of water. When ready to develop the prints, add ten drops of the bichromate of potash to the developer. Place the prints in the developer face down, taking care that no air-bubbles form on the surface of the paper. When the paper is thoroughly saturated it can be turned face up. Leave the prints in the developing bath for at least twenty minutes, then, without washing, place them in the dish containing some of the ammonia and water. This is the fixing bath. Leave them in this bath for about ten minutes, then turn out and cover with fresh ammonia and water. Let them remain ten minutes in this second fixing bath, wash and dry.
The prints made on this paper closely resemble platinotype prints, but the process is much cheaper. If purplish tones are desired, make up a developing bath with a quarter-ounce of borax instead of three-quarters. The developer containing the three-quarter ounce of borax gives black tones. The bichromate of potash added to the developing solution keeps the prints clean and increases contrast.