As this may be a rather uncommon field of processes, I write what I found in
Eder & Trumm: Die Lichtpausverfahren..., (Eder Handbuch IV/4) 1929, p. 158 ff:
Burnett made the observation that uranium nitrate decomposed when exposed to
light in 1857. 1858-60 Niepce de Saint-Victor published his findings about
uranium salts as basis for photographic copy processes. In 1860 Poitevin
discovered, that images on paper coated with ferric chloride and uranium nitrate
could be made visible by exposure to tannic, gallic or pyrogallic acid.
Niepce simply soaked the paper in a solution of 1 part uranium nitrate and 5
parts water and dried over a fire. Later he and Bovier recommended the
following, improved process:
Water 120 ccm
uranium nitrate 20 g
soft gelatin 10 g
acetic acid a few drops
solve with a little heat, then soak cold pressed paper or coat with a brush,
then dry in the dark (Bovier 1896). The gelatin could probably be replaced by
starch. Exposure shall be three times as long as with platinum.
For red images: soak in a 2-10% solution of ferric cyanide, then wash.
These images can be turned green to blue by soaking in a 4% copper-II-sulfate
solution with a little sulfuric acid, or they can be turned green in a 2% (1+50)
solution of cobalt nitrate.
Violet images you can get by a short wash in water and then soaking in a 1/2 %
goldchloride solution.
If you soak the paper in silver nitrate, the image wil be greyish black.
The other two pages with processes that include uranium I better leave away,
unless you have a pleasure for wismuth and other stuff that may make you glow in
the dark... ;-) Uranium toning however was considered of beeing not very stable
- I don't know about the images that result from the formulas above. Never tried
it...
Klaus Pollmeier