uick enough in the air, but when the weather is warm and damp, the
gelatine, drying very slowly, may be so softened as to run off, or to
produce an entirely objectionable reticulation, or the defects above
mentioned. This may be avoided by drying it pinned up in a box, or a
closet, over quick-lime.

When dry, the tissue is generally wrinkled, brittle, breaks easily in
handling and cannot be laid flat on the cliche; but by holding it over a
basin of boiling water, the steam in a few moments rendering it
sufficiently pliable to lay it flat between glass plates, where it should
be kept under pressure until wanted for use.

The writer always dries the tissue in the following manner, which he
devised about sixteen years ago.(27) And not only the least trace of
reticulation is avoided, but the tissue, drying quite flat, lies in
perfect contact with the negative, which is quite important to obtain
proofs exactly sharp all over.

A clean glass plate is rubbed with talc, or, which the writer prefers,
flowed with a solution of(28)
Yellow wax, pure 1 part
Benzine, pure 100 parts

then strongly heated, allowed to cool and rubbed clean (apparently) with a
piece of flannel. After once more repeating this operation the plate is
coated with the following plain collodion:(29)

Ether, conc. 250 parts, in volume
Alcohol, 95 deg 250 parts, in volume
Pyroxyline 3 parts

When the film is set, the plate is immersed in filtered water until
greasiness has disappeared, when on its removal from the bichromate bath
the tissue is laid, without draining, upon it and pressed into contact
with the squeegee to remove the excess of liquid and, with it, the air
bubbles interposited. The tissue is then allowed to dry in the air on the
collodionized plate in the cold season, or, when the weather is warm and
damp, in a box in the bottom of which is placed a quantity of quicklime in
earthen dishes. When dry, the plates are placed one upon another, wrapped
in paper and kept in a dry place. When wanted for use the tissue is
stripped off and will be found quite flat with a beautiful surface to
print upon.

One should avoid to keep the sensitized tissue in a moist and warm
atmosphere, for in less than ten hours it becomes insoluble even in
complete darkness. It should neither be kept in the air contaminated with
gaseous reductive matters, such as the products of the combustion of coal
gas and petroleum, sulphydric or sulphuro