her investigation
and discussion.

For mounting prints upon developed gelatine paper, it has been
recommended to cement the edges only, so as to leave the greater part of
the print with its enamel surface. This plan is unsatisfactory, for two
reasons, besides the objection on the ground of distortion. There is a
rough-looking margin which spoils the continuity of appearance,
especially (as in the specimens I have seen) where the line of cement is
not kept at an exact width, but encroaches here and there.

Secondly, the print, from not being attached to the mount all over, is
apt, especially when in a large size, to be somewhat wavy and wanting in
flatness. Another plan recommended, as giving a surface resembling
albumen paper, is to paste the back of the print without moistening the
surface, and so mount. Some prints that have been shown thus treated had
so strongly curled the cards upon which they were mounted that it is
evident there was considerable strain and consequent distortion.

A third plan recommended is to paste the back of the print while in
contact with the glass upon which it has to dry; and, when dried, to
mount by passing through a rolling press with a damped card. This plan
looks, at first sight, like that recommended for albumen paper, and
called "dry" mounting. Consideration, however, will show that there is a
radical difference. In the case of the albumen paper the print has been
dried without strain, and therefore but little change is to be looked
for, while the print dried in contact with glass is strained to the
utmost, causing present distortion and future curling of the mount.
Perhaps the evil of distortion caused by enameling may be reduced to a
minimum by soaking the print in alcohol previous to laying it upon the
glass.

Since the distortion of the photograph arises from the unequal expansion
of the paper when wet, it becomes a question whether something may not be
done in the selection of the paper itself. It may be that some makes vary
much less than others in the "length against width" extension of the
surface by wetting. It must be remembered that for gelatine emulsion we
are not nearly so limited in the selection of paper as when it is
required to be albumenized. In the latter case the image is in the paper,
whereas with gelatine the image is contained in the surface coating. I
may mention that the best plain, i.e., not enameled, but resembling that
of ordinary albumen paper, surface