Niepce De St Victor's Process 1859

Red Prints.





Float the paper for fifteen or twenty seconds on a 20 per cent. solution

of nitrate of uranium and dry before the fire in the dark room. This

paper can be prepared many days before use. Expose in sunshine from eight

to ten minutes, according to the intensity of the light and the quality of

the negative, then wash in moderately warm water (50 to 60 deg. C.) for a

few seconds. T is done, immerse in a solution of red prussiate of potash

at 2 per cent. of water; in a few moments the proof will become of a fine

blood-red color, like "sanguine." Wash, etc.





Green Prints.





Make a red print as above described, immerse it for a few minutes in a

solution of nitrate of cobalt and dry it without washing. Fix then in a

solution of sulphate of iron at 20 per cent. of water and 4 of sulphuric

acid. Wash and dry before the fire.





Violet Prints.





Prepare the paper in the uranium bath, expose, wash and develop in a

solution of chloride of gold, 1:200, until the proof has assumed a fine

violet color. Wash in several changes of water.





Blue Prints.





Sensitize the paper with a red prussiate of potash solution at 20 per 100.

Let dry, expose until the proof is slightly blue; immerse it for five or

ten seconds in a saturated solution of bichloride of mercury, wash only

once and immerse in a solution of oxalic acid--saturated when cold--heated

to about 55 deg. C. Wash in three or four waters and let dry

spontaneously.





Black Prints.





Float the paper on a mixture by equal volumes of a solution of iron

perchloride and another of uranium nitrate, each at 10 per 100 of water.

Expose and develop on a saturated solution of gallic acid.