COLOUR PHOTOGRAPHY 347 
Sodium hyposulphite 0.10 g 0.77 gr. 
-Ammonia, sp. gr. 0.88 20 ccm 154 min. 
Water to 1000 ccm 16 oz. 
For use dilute with an equal volume of water. The small 
quantity of hypo causes the image to reverse in this solution, 
and development should be carried on until the highlights or 
flesh tones just begin to show reversal, when viewed against 
the light. Instead of using hypo, an excellent developer is 
obtained by using potassium ferrocyanide, 4g (31 gr.). 
The following is stated to commence the development from 
the bottom of the film: 
Amidol 6.6 g 51 gr. 
Sodium sulphite, dry 19¢ 145 gr. 
Sodium bisulphite lye 19 ccm 145 min. 
Potassium bromide 19to3.3¢ 14.6to25 gr. 
Water 1000 ccm 16 oz. 
Reversing solution: 
A. Potassium permanganate 2¢g 15 gr. 
Water 500 ccm 8 oz. 
B. Sulphuric acid, c. p. 10 ccm 77 min. 
Water 500 ccm 8 oz. 
Mix in equal volumes just before use. The A solution must 
be kept in the dark. The following is preferable, being free 
from some disadvantages of the permanganate: 
Potassium bichromate 5g 38 gr. 
Sulphuric acid, c. p. 10 ccm 77 min. 
Water 1000 ccm 16 oz. 
SECOND DEVELOPMENT.—Any developer may be used for 
the second development after reversal; the makers recom- 
mend: 
Sodium sulphite, dry I5¢ 115 gr. 
Amidol 2 38 gr. 
Water | 1000 ccm 16 oz. 
