er
up, or lay it down upon its dry side, and when it becomes tolerably dry
(perfect dryness is not requisite), immerse it in common cold water for the
space of four hours, changing the water during that time three or four
times, so that all the soluble salts may be removed; often move the papers,
so that when several sheets are together, one does not press so much upon
another that the water does not equally arrive at all the surface.

If this paper is well made, it is of a pale straw colour, or rather
primrose, and perfectly free from unevenness of tint. It will keep good for
several years; if, however, the soluble salts have not been _entirely_
removed, it attracts damp, and becomes brown and useless or uncertain in
its application.

Some of our oldest and most successful operators still adhere to and prefer
the iodized paper prepared by the double process, which certainly effects a
saving in the use of the iodide of potassium. The following is the easiest
way of so preparing it:--Having floated your marked surface of the paper on
a 30-grain solution of nitrate of silver, and dried it[4], immerse it for
20 minutes in a solution of iodide of potassium of 20 grains to the ounce,
when it immediately assumes the desired colour. It is then requisite,
however, that it should undergo the same washing in pure water as the paper
prepared by the single process.

Upon the goodness of your iodized paper of course depends your future
success. Although it is not requisite to prepare it by candle-light (which
in fact is objectionable from your inability to see if the yellow tint is
equally produced), I think it should not be exposed to too strong a light;
and as the fly-fisher in the dull winter months prepares his flies ready
for the approaching spring, so may the photographer in the dull weather
which now prevails, with much advantage prepare his stock of iodized paper
ready for the approach of fine weather.[5]

Many other ways of iodizing paper have been recommended which have proved
successful in different hands. Dr. Mansell, of Guernsey, pours the iodide
solution upon his paper, which previously has had all its edges turned up
so as to resemble a dish; he rapidly pours it off again after it has
completely covered the paper, and then washes it in three waters for only
ten minutes in all: he considers that thereby none of the size of the paper
is removed, and a more favourable action is obtained. In the experiments I
have trie