According to the literature (to be taken with a grain of "salt" , in
this case ammonium chloride) the salt should be equal in concentration
to the salt in the albumen, the theory being that if this condition is
created, the alcohol will not leach ammonium chloride from the albumen,
decreasing its strength. The problem I have with this theory is that
when the albumen is "wet" it has a much larger volume than when it is
dry, thus the percentage of salt is much higher after the layer of
albumen has dried and shrunk. I have read in several places that a wet
layer of gelatin is ten times thicker than when it is dry, and can't
think of a reason that the albumen would behave much differently.
Heat will also coagulate albumen (ever fried an egg?), so I run my
'bumenized sheets through the dry mount press before I sensitize, to
harden and make the sheets easier to handle and float on the silver
nitrate solution.
John