THE USE OF ALBUMEN ON GLASS PLATES AND ON PAPER. 287
hang it up to dry, which it usually does in six to eight minutes;
then lay it on a vessel containing a solution of 25 parts of nitrate
of silver in 100 parts of water. Leave the paper on the solution
for at least six minutes, then place it on a plate to dry.
The serum of milk has also been employed on paper as a
quickening agent, and some of the French authorities speak
highly of it ; but I am not enabled from my own experience to
speak of its advantages.