ORTHOCHROMATIC'! PHOTOGRAPHY 27 
F. Silver chloride 2¢g 1.54 gr. 
Ammonia, 22° 80 ccm 61 min. 
Distilled water 920 ccm 16 oz. 
The ammonia should have a spose gravity of about 0.92. 
Sensitising bath: 
G. Solution E 100 ccm 1 z., 288 min. 
Solution F 100ccm 1 oz., 288 min. 
Alcohol, 22.5° 800 ccm 13 oz. 
This alcohol contains approximately 50 per cent water. The 
plates should be bathed at as low a temperature as possible, 
the dish rocked for 3 minutes, the plates rinsed for 1 minute, 
and then dried as rapidly as possible. It is possible to take 
snapshots with plates thus bathed in well-lighted rooms with 
a lens working at f: 4. 
Various formulas have been given for panchromatising 
plates, some of which are given here. As a rule, the fastest 
plates should not be used, as they are more liable to fog on 
keeping; and a clean working plate should be chosen. 
Wallace’s Bath— 
Pinacyanol 15/cen: 115 min. 
Pinaverdol 12 ccm 92 min. 
Homocol 12 ccm 92 min. 
Ammonia 35.7 ccm 270 min. 
Alcohol 410 ccm 634 oz. 
Water 590 ccm OY oz. 
Bathe for 4 minutes, rinse in alcohol for 30 seconds, dry. 
Sensitises to 720, without any gap in the blue-green. 
Dicyanine may be used instead of the homocol with slightly 
greater speed. 
Greenfield's Bath——This bath is specially intended for 
tank work, but the solution should not be used more than 
twice: 
Pinachrome 3 ccm 23 min. 
