Four stock solutions are required.
A) ammonium thiocyanate........... 2.5%
B) sodium phosphate, mono, anhy... 2.5%
C) borax.......................... 2.5%
D) gold cloride................... .25%
These solutions are mixed in equal parts to make the working strength
toner. The solution should be mixed just before use, because it becomes
inactive rapidly. The toner is applied to the print immediately after
exposure, without any preliminary washing. The toner is applied to the
print with a brush or glass coating rod. The print precipitates a white
scum (a silver compound?) but ignore it. keep applying the toner for
several minutes untill it changes color. Then fix it.
The advantages of this method are:
1) it saves time, since no pre-rinse is needed.
2) it is more consistant, because it is used as a one-shot.
3) it gives a very rich purple tone and seems to bleach less in the fix.
The formula is from a little book called "How to Make Prints in Colors"
by Frank R Frapie, vol. 4 of the Practical Photography Series published
by American Photographic Publishing Co, Boston MA, 1921.
"Printing in color" in this volume refers to achieving various hues
through the use of different emulsions, toners, etc. There is a section
on "printing in natual colors" in the back.
Peter Mumford