348 PHOTOGRAPHIC FACTS AND FORMULAS 
INTENSIFICATION.—The following silver intensifier was 
recommended by the makers: 
A. Pyrogallol 3g 23 gr. 
Citric acid 32g 23 gr. 
Water 1000 ccm 16 oz. 
B. Silver nitrate 5g 84 er. 
Water 100 ccm 3Y4 oz. 
For use add 10 parts B to 100 parts A, and immediately apply 
to the plate. The mixed solutions rapidly turn cloudy; then 
the solution should be poured away, and fresh applied. This 
should not take more than about 30 seconds, as a rule; then 
the plate should be well washed, immersed in a 2 per cent 
solution of the clearing bath, well washed, and fixed. The 
following intensifier may also be used: 
Cupric sulphate 20 g 154 gr. 
Potassium bromide 20 g 154 er. 
Hydrochloric acid 5 ccm 38 min. 
Water 1000 ccm 16 oz. 
As soon as the plate is bleached, rinse rapidly, and treat with 
a 5 per cent solution of silver nitrate; then clear in a neutral 
permanganate bath, and redevelop with amidol or treat with a 
5 per cent solution of sodium bisulphite. 
_ VARNISHING.—The makers recommend: 
Gum dammar 200 g 3¥ oz. 
Benzole 1000 ccm 16 oz. 
The following is preferable as being less dangerous as 
regards fire risks: 
Gum dammar 20 g 154 gr. 
Manilla copal, powdered 50 g 384 gr. 
Carbon tetrachloride 1000 ccm 16 oz. 
As soon as the resins are dissolved, the mixture should be 
heated to the boiling point, and then filtered while hot. 
Tue Pacet PLate.—With this a separate panchromatic 
