of these several processes are too apt to be
prejudiced in favour of the works produced by them.

Before proceeding farther, permit me to observe, that if some of my remarks
appear _too_ elementary, and _too_ well known by many assembled here, my
reason for making them is, that I have myself experienced the want of
_plain simple rules_, notwithstanding the many able treatises upon the
subject which have already been written: I hope, therefore, I shall receive
their pardon for entering fully into detail, because a want of success may
depend upon what may appear most trivial.

I think the greatest number of failures result from not having good iodized
paper; which may be caused by

1. The quality of the paper;
2. The mode of preparing it;
3. The want of proper _definite_ proportions for a particular make of
paper;

because I find very different results ensue unless these things are
relatively considered.

I have not met with satisfactory results in iodizing the French and German
papers, and the thick papers of some of our English makers are quite
useless.

Turner's paper, of the "Chafford Mills" make, is greatly to be preferred,
and therefore I will presume that to be used, and of a medium thickness.
The great fault of Turner's paper consists in the frequent occurrence of
spots, depending upon minute portions of brass coming from the machinery,
or from the rims of buttons left in the rags when being reduced to pulp,
and thus a single button chopped up will contaminate a large portion of
paper; occasionally these particles are so large that they reduce the
silver solutions to the metallic state, which is formed on the paper; at
other times they are so minute as to simply decompose the solution, and
white spots are left, much injuring the effect of the picture.

Whatman's paper is much more free from blemishes, but it is not so fine and
compact in its texture; the skies in particular exhibiting a minutely
speckled appearance, and the whole picture admitting of much less
definition.[3]

All papers are much improved by age; probably in consequence of a change
which the size undergoes by time. It is therefore advisable that the
photographer, when he meets with a desirable paper, should lay in a store
for use beyond his immediate wants.

It may not be inappropriate to mention here, in reference to the minuteness
attainable by paper negatives, that a railway notice of six lines is
perfectly legible, and