170 PHOTOGRAPHIC FACTS: AND FORMULAS 
Collodion, 4% 2100 ccm 33Y4 oz. 
Ether 360 ccm 534 oz. 
Add: 
Phosphoric acid, sp. gr. 1.725  10ccm 77 min. 
Then add: 
Citric acid 80 g 614 min. 
Alcohol 140 ccm 21% oz. 
Shake well, and add: 
Silver nitrate 100 g 770 gr. 
Hot water 115 ccm 883 min. 
Alcohol 200 ccm 3% oz. 
Shake thoroughly, and add: 
Lithium carbonate 14.5¢ 111 gr. 
Till there is no longer any effervescence, and add: 
Glycerine 15 ccm 115 gr. 
Alcohol 15 ccm 115 gr. 
Calcium chromate, 10% sol. 0.5 ccm 3.8 gr. 
This paper may be toned in the ordinary way or, if treated 
with 2.5 per cent solution of citric acid, till the yellow colour 
disappears and then washed, it gives rich brown tones on 
fixation in a hypo plus sulphite bath. Or the following may 
be used: 
Collodion, 344% 1960 ccm 31% oz. 
Phosphoric acid 9 ccm 69 min. 
Citric acid 772 591 gr. 
Alcohol 130 ccm 998 min. 
Shake well, and add: 
Silver nitrate 100 g 770 gr. 
Ammonia q.S. q. S. 
Coarsely powder the silver, add very cautiously enough am- 
monia to form a clear solution, and add: 
Alcohol 320 ccm 5 oz. 
