TONING BROMIDE PRINTS 223 
Water | 1000 ccm 16 oz. 
In the following, direct toning is used, a single bath being 
employed; the first is by Somerville: 
A. Ferric chloride 2.32 16 gr. 
Oxalic acid, sat. sol. 120 ccm 2 OZ. 
Vanadium chloride 46¢ 32 gr. 
Nitric acid 10.5 ccm 80 min. 
Water : 500 ccm 8 oz. 
B. Potassium ferricyanide 2.32 16 gr. 
Water 500 ccm 8 oz. 
Mix just before use. Duration of toning 2 to 4 minutes; 
wash and fix in: 
Hypo 200 g Zaz 
Boric acid 40g 200 gr. 
Water 1000 ccm 10 oz. 
Finally, wash for 10 minutes. 
The disadvantage of the above baths is that some opaque 
silver chloride is formed, so that the results are somewhat 
muddy and control of the colour is not easy. By using 
vanadium oxalate or sulphate, much brighter colours and 
clearer prints are obtained (Wall). It 1s necessary to make 
these salts, but this is an easy task: 
Ammonium metavanadate 100's) 302, 130\er: 
Oxalic acid, pure 460 gers 1 Ib. 
Water 500 ccm 17¥ oz. 
Mix into a cream in a beaker or porcelain dish, and heat 
gradually with constant stirring. Solution gradually takes 
place, and the colour turns to orange and greyish-blue, but, 
as the heat is continued, it becomes a bright blue. Finally, 
add water until the bulk measures 1477 ccm (520z.). If 
the sulphate is to be used, although it presents no advantages, 
use: 
Ammonium metavanadate 100 9) 3iaz.) 130 ier: 
