PEATINOTYEE 281 
Mercuric chloride, 
5% sol. O:2'to l'cem) 3. to’ l/min. 
Sodium chloroplatinate 2to10drops 2to 10 drops 
Water 2to4ccm 33 to 67 min. 
The quantity of water is as before regulated by the surface 
of the paper. The solution should be applied in the manner 
already described. The best developer for this paper is: 
Potassium oxalate 100 ¢ 770 gr. 
Potassium phosphate 50 g 380 gr. 
Citric acid 20 g 154 gr. 
Potassium chloride 10g 77 SE: 
Water 1000 ccm 16 oz. 
Weeeea temperature of 70° EG: (158... 
CoLtp BatH PAPER (Lainer).— 
A. Ammonium ferric oxalate 50 ¢ 134 oz. 
Water 58 ccm 2 oz. 
Oxalic acid, 10% sol. 8 ccm 150 min. 
B. Potassium chloroplatinite 2¢g 30 gr. 
Water 10 ccm 150 min. 
The sensitiser for 3352 qcm (520 sq. in.) should be: 
A solution 4 ccm 68 min. 
B solution 8 ccm 136 min. 
Potassium bichromate, 4% sol. 8 ccm 136 min. 
Immerse the exposed print for from 1 to 3 minutes in the 
developer, special salts being supplied for this, until fully 
developed ; then clear in four acid baths of hydrochloric acid, 
1:60, and wash for a short time in running water. For 
sepia prints the developer should be heated to 66° to 88° C. 
(150° to 190° F.), and the prints cleared in three acid baths 
of half the above strength. Development should be effected 
in a feeble white light. The addition of 2 to 4 drops of a 
10 per cent solution of potassium bichromate to the developer 
increases the brilliancy of the prints. 
