being so easily injured, are much better
preserved, all actual contact with the positive being avoided. For the same
reason, by this process positive impressions can be obtained not only upon
wet paper, &c., but also upon hard inflexible substances, such as
porcelain, ivory, glass, &c.,--and upon this last, the positives being
transparent are applicable to the stereoscope, magic lantern, &c.

"By adopting the following arrangement, this process may be used largely to
increase the power and speed of reproduction with little loss of effect.
From a positive thus obtained, say on collodion, _several hundred_
negatives may be produced either on paper or on albumenised glass. If on
the latter, and the dimension of the original negative is preserved, the
loss in minuteness of detail and harmony is almost imperceptible, and even
when considerably enlarged, is so trifling as in the majority of cases to
prove no objection in comparison with the advantage gained in size, while
in not a few cases, as already stated, the picture actually gains by an
augmentation of size. Thus, by the simultaneous action, if necessary, of
some hundreds of negatives, many thousand impressions of the same picture
may be produced in the course of a day.

"I cannot but think, therefore, that this simple but ingenious discovery
will prove a valuable addition to our stock of photographic manipulatory
processes. It happily turns to account and utilises one of the chief
excellencies of collodion--that extreme minuteness of detail which from its
excess becomes almost a defect at times,--toning it down by increase of
size till the harshness is much diminished, and landscapes, always more or
less unpleasing on collodion from that cause, are rendered somewhat less
dry and crude.

"A very little practice will suffice to show the operator the quality of
glass negatives--I mean as to vigour and development--best adapted for
reproducing positives by this method. He will also find that a great power
of correction is obtained, by which overdone parts in the negative can be
reduced and others brought up. Indeed, in consequence of this and other
advantages, I have little doubt that this process will be very generally
adopted in portrait taking.

"Should your old idea of preserving public records in a concentrated form
on microscopic negatives ever be adopted, the immediate positive
reproduction on an enlarged readable scale, without the possibility of
injury to the p