Queries on Sir W. Newton's Process.—The process of Sir W. Newton is nearly similar to one I have successfully used for some years, and I can recommend it as effective and simple.
A difficulty I have lately found, has been with my iodized paper, which, when freshly used, is well enough; but if kept a month or two, will only allow of the paper being prepared to take views just before using. I should much like to know how this occurs.
If Sir W. Newton would answer the following Queries, he would add to the obligations that many others besides myself are under to him:
1. What paper does he use for positives, and what for negatives?
2. Is it not better to dissolve the silver and iodide of potassium in three ounces of water each instead of one (see "N. & Q.," Vol. vii., pp. 151. 277.)?
3. Is spring water fit for washing the iodized paper; if it contains either sulphate or bicarbonate of lime or muriate of soda?
4. How long ought the iodized paper to keep good?
5. How long should the negative paper (on a moderately warm day) keep after being made sensitive, before exposing to the action of light; and how soon after that should it be developed?
John Stewart.