PLATING? VEE 287 
print. Then charge the brush with C solution, and paint 
those parts which it is desired to bring out more than the 
rest. Finally, treat any desired part with D solution. The 
glycerine merely prevents any lines of demarcation showing. 
The subsequent acid bath treatment is as usual. 
_ INTENSIFYING PLATINOTYPES.—Weak platinotype prints 
can be intensified, and, unless much under-printed, good re- 
sults are obtained. 
Silver intensification ( Clarke) —This is extremely liable 
to give a coarse granular deposit, which makes it unsatisfac- 
tory on the whole: 
Glacial acetic acid 150to 160 drops 50 to 60 drops 
Pyrogallol 2g 13.5:er. 
Water 1000 ccm 16 oz. 
Dissolve, and add: 
Silver nitrate, 12% sol. 20 drops 8 drops 
It is advisable to flood the print, which must be quite free 
from iron salts and acid, with the pyro solution, then to pour 
off the solution; add the silver to it, again flood the print, and 
repeat until sufficient intensity is attained. Hydrochinon or 
metol may be used instead of the pyrogallol. The print 
should be well washed, and, finally, fixed in weak hypo. 
Intensification with platinum (V ogel) — 
Potassium oxalate developer 5ccm 80 min. 
Water 50 ccm 800 min. 
Potassium chloroplatinite 
sol. 3to5drops 3to5drops 
This also tends to give coarse grain, and the whites are very 
apt to be stained. Far better results are obtained by the 
following (Hubl) : 
A. Sodium formate, 10% sol. 
B. Platinum perchloride, 2% sol. 
For use add 5 parts A to 200 parts water, and then add 5 
