The Dictionary Of Photography

A True Historic Record Of The Art & Practice Of Photography 100 Years Ago.

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Enlarging
A clean pad of linen should be used till the film shows no sign of greasine'ss, and is then allowed to dry thoroughly. The follow-ing solution is then made : -
Gelatine ............... 7 parts.
This is allowed to soak in
Distilled water ............250 parts
till soft, and then dissolved by the aid of a gentle heat. In the meantime take
Fresh egg albumen...... ... ... 50 parts
and mix with
Distilled water ......... ... 125 parts.
Add
Potassium iodide ... ... ... .., 9 parts.
Ammonium bromide          ... ... ... 4 .,
Ammonium chloride          ... ... ... 1.25 ,,
Beat the solution well, allow to stand for about one hour, filter through flannel, and add to it
Distilled water ............ 125 parts
and the solution of gelatine "prepared as above. The solution is flowed over the surface- of the canvas, or, preferably, applied with a Buckle or Blanchard brush, or small piece of sponge. The coated canvas is then allowed to dry, and several thus prepared may be stored for use, and sensitised as required by the fol-lowing solution : -
Silver nitrate           ... ......... 20 parts.
Glacial acetic acid ... ......... 10 ,,
Distilled water ...... ...... 240 ..
A small quantity of this is poured on to the gelatinised canvas, and evenly distributed with a Buckle brush, and exposed while still wet, allowing about seventy-five seconds to elapse between sensitising and exposing. This is fairly sensitive, about sixty seconds being required for a good light from a clear sky with an ordinary negative. When the exposure is complete, develop with
Gallic acid ............... 3-5 parts.
Lead acetate           ............ -6 ..
Distilled water ...... «.« .., 250 ..
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