SULPHIDE, TONING 245 
Reducing sulphide-toned prints—Sulphide toned prints 
may be reduced by treatment with most of the usual negative 
reducers or with chlorine and bromine water, solutions of 
iodide, permanganate, and sulphuric acid. The most satis- 
factory are solutions of cupric chloride or bromide, the 
latter for preference (Smith). The chloride reducer is 
equal parts of a 5 per cent solution of cupric chloride and a 
15 per cent solution of common salt. The bromide reducer is: 
Cupric bromide . Toe 58 ger. 
Sodium bromide O25s 480 gr. 
Water 1000 ccm 16 oz. 
The cupric bromide in this bath may be replaced by using 
8.5¢ (65 gr.) cupric sulphate, and increasing the sodium 
bromide by 8g (61 gr.). After reduction the prints should 
be immersed for 2 minutes in a 5 per cent solution of hydro- 
chloric acid, and washed for about 10 minutes. 
Partial development and sulphiding—Bleach the prints in 
the usual ferricyanide and bromide mixture, wash for 90 
seconds in running water, and immerse for various times in 
the following developer ; rinse for 30 seconds, and treat with 
the usual sulphide bath. 
Metol 18¢ 14 gr. 
' Hydrochinon 46¢ S51et: 
Sodium sulphite, dry 922 70 gr. 
Borax 18.4 ¢ 140 gr. 
Water 1000 ccm 16 oz. 
The following table shows the various tones obtained : 
