Wellington.
[The resultant iodide from fifteen grains of nitrate of silver,
precipitated by means of the iodide of potassium, will give the
requisite quantity of iodide for every ounce of water; or about
twenty-seven grains of the dried iodide will produce the same effect.
It is however far preferable, and more economical, to convert all waste
into chloride of silver, from which the pure metal may be again so
readily obtained. Iodide of silver, collected in the manner described
by our correspondent, is very likely to lead to disappointment.]
_Albumenized Paper._--I have by careful observation found that the cause of
the albumen settling and drying in waving lines and blotches on my paper,
arose from some parts of the paper being more absorbent than others, the
gelatinous-like nature of the albumen assisting to retard its ready ingress
into the unequal parts, and, consequently, that those places becoming the
first dried, prevented the albumen, still slowly dripping over the now more
wetted parts, from running down equally and smoothly, thereby causing a
check to its progress; and as at last these become also dry, thicker and
irregular patches of albumen were deposited, forming the mischief in
question.
The discovery of the cause suggested to me the propriety of either giving
each sheet a prolonged floating of from ten to fifteen minutes on the
salted albumen, or until every part had become fully and equally saturated;
or, as a preliminary to the floating and hanging up by one corner on a
line, of putting overnight between each sheet a damped piece of bibulous
paper, and placing the whole between two smooth plates of stone, or other
non-absorbent material.
Either method produces equally good results; but I now always use the
latter, thereby avoiding the necessity of otherwise having several dishes
of albumen at work at once.