DR. MANSELL having forwarded to me for publication the accompanying account
of his mode of operation, I have much pleasure in laying it before the
readers of "N. & Q.;" because my friend DR. MANSELL is not only so
fortunate in his results, but is one of the most careful and correct
manipulators in our art. The proportions which he recommends, and his mode
of operating, are, it will be seen, somewhat different from those hitherto
published. In writing to me he says: "I make a point of making a short note
in the evening of the day's experiments, a plan involving very little
trouble, but of great service as a reference." If all photographers would
adopt this simple plan, how much good would result! DR. M. complains to me
of the constant variation he has found in collodion; (with your permission,
I will in your pages furnish him, and all your readers with some plain
directions on this point); and he has given me some excellent observations
on the "fashionable" waxed-paper process, in which he has not met with such
good results as he had anticipated; although with much experience which
_may_ some day turn to good account. DR. MANSELL concludes with an
observation in which I entirely concur, viz. "That the calotype process is
by far the most useful; and I find the pictures it gives have better effect
than the wax ones, which always to me appear flat, even when they are not
gravelly."