192 PHOTOGRAPHIC FACTS AND FORMULAS 
Dissolve the silver, add enough strong ammonia to form a 
clear solution, and then add: 
Silver nitrate 32 g 245 ger. 
Water 250 ccm 4 oz. 
If necessary add a little more ammonia to clear up any 
precipitate formed. Papers thus prepared will not keep more 
than a few hours, but they print very rapidly, and give very 
vigorous prints. It is better to use the plain silver solu- 
tions, and fume the paper with ammonia just before use. 
This can be effected by cutting the paper to size and pinning 
to the inside of the lid of a plate box, on the bottom of which 
is a sheet of blotting paper wet with a 10 per cent solution 
of ammonia. About 10 to 15 minutes will be sufficient. In- 
stead of the liquid ammonia, coarsely powdered ammonium 
carbonate may be used, and then the paper should be fumed 
for 30 minutes. 
Printing should be carried rather deep and the prints 
washed with repeated changes of water until no milkiness is 
seen in the water, or a 5 per cent solution of salt may be used, 
and the prints then washed for 10 minutes. Toning may be 
effected with either gold or platinum. Weak baths give the 
best results, such as: 
Borax 7g 34 gr. 
Gold chloride 0.11 g 0.85 gr. 
Hot water 1000 ccm 16 oz. 
Sodium phosphate or acetate may be used instead of the 
borax, and the tones vary from sepia to purple, according to 
the duration of toning. As the prints always dry a little 
colder, or bluer, in tone than when wet, allowance should be 
made for this. A suitable platinum bath is: 
Potassium chloroplatinite 0.3 ¢g 2.08h 
Citric acid 8g 61 gr. 
Salt 2.5 ¢ 19 gr. 
