TONING BROMIDE PRINTS ZN, 
Potassium ferricyanide, 
10% sol. 30 ccm 218 min. 
Water 800 ccm 12 oz. 
This gives cherry red tones with a faint tinge in the whites. 
Potassium oxalate, 10% sol. 100 ccm 14 oz. 
Cupric sulphate, 10% sol. 40 ccm 288 min. 
Tartaric acid, 10% sol. 10 ccm 72 min. 
Potassium ferricyanide, 
10% sol. 30 ccm 216 min. 
Water | 800 ccm 12 oz. 
This gives red-brown tones. The addition of 100 ccm (1y% 
oz.) saturated solution of ammonia alum gives browner 
tones. 
Ammonium oxalate, sat. sol. 200 ccm 3 0z. 
Cupric sulphate, 10% sol. 40 ccm 288 min. 
Oxalic acid, sat. sol. 10 ccm 72 min. 
Potassium ferricyanide, 
10% sol. 30 ccm 216 min. 
Water 800 ccm 12 oz. 
This gives a reddish-violet tone. The following bath gives 
the so-called red chalk or Bartolozzi tones, but the whites 
are tinged: 
Ammonium carbonate, 
sat. sol. 570 ccm 8 oz. 
Cupric sulphate, 10% sol. 127 ccm 856 min. 
Potassium ferricyanide, 
10% sol. 304 ccm 5 oz. 
A weak ammonia bath, 1 per cent, will clear the whites. The 
following gives reddish-brown tones with clear whites (Crab- 
Eree)): 
Cupric sulphate i2e2 2st) 
Potassium citrate 752 576 gr. 
Ammonium carbonate 6g 46 er. 
