Since I wrote to you last, I have tried a solution of twelve grains only of
nitrate of silver to the ounce of distilled water, for the paper
albumenized, as mentioned in my letter of the 13th of February, and have
found it to answer perfectly. The paper I used was _thin_ Canson, floated
for one minute exactly on the solution; but I have no doubt the thick
Canson will succeed just as well; and here I may observe that I have never
found any advantage in allowing the paper to rest on the solution for three
or four minutes, as generally recommended, but the contrary, as the paper,
without being in the least more sensitive, becomes much sooner discoloured
by keeping. My practice has been to float the thin Canson about half a
minute, and the thick Canson not more than a minute.