Edinburgh.
_Sisson's developing Solution_ (Vol. vii., p. 462.).--Will you be so good
as to ask MR. SISSON if he finds the above to answer as a bath to plunge
the plate _into_, instead of pouring on, as in the case of pyrogallic?
He is entitled to the warm thanks of all photographers for the discovery
of a solution which produces such pleasing tints with so much ease; and
it needs but the qualification I inquire after to render it perfect. I
have used it when at least three weeks made, and am not sure that it is
not even better than when fresh.