SICVvEk | PRINTING PROCESSES 169 
Water 16 ccm 123 min. 
Glycerine 8 ccm 62 min. 
Eder.— 
Pyroxyline 21g SZ ion: 
Alcohol 600 ccm 9Y4 oz. 
Ether 400 ccm 6Y, oz. 
Citric acid 5g 38 gr. 
Lithium chloride, cryst. Ses eS) ox: 
Strontium chloride, cryst. ag 23 oY: 
Silver nitrate l4¢ 107¥Y gr. 
Water 10 ccm 77 min. 
Glycerine 4 ccm 31 min. 
V alenta.— 
Pyroxyline 2253 VAS) tae: 
Alcohol 500 ccm 8 0z. 
Ether 500 ccm 8 oz. 
Citric acid 18g 138 gr. 
Calcium chloride, cryst. 14¢ 10.7 er. 
Silver nitrate 18¢ 138 gr. 
Water 10 ccm 77 rin. 
Glycerine 2a eeu 19 min. 
FLATTENING.—Collodion papers when toned may need to 
be flattened by immersing them one by one face down in a 
smooth-bottomed tray containing a very little water. As 
soon as all are in, drain off the water and let the tray stand in 
a slanting position for ten minutes before toning. If this is 
not done, the prints may curl up badly. Subsequent manipu- 
iavionsvace the sameas for P.O. P.- 
SILVER PHOSPHATE PAPER.—These are very rapid-printing 
papers with long scale of gradation. The phosphate emul- 
sions can be used alone or mixed with citro-chloride emulsions 
to increase the speed: 
