The process I am about to describe is so simple, and I hope to make it so intelligible to your non-photographic readers, that a perfect novice, using ordinary care, must meet with success; but should I fail doing so upon all points, any information sought through the medium of "N. & Q." shall meet with explanation from myself, if not from other of your experienced correspondents, whose indulgence I must beg should the communication be deemed too elementary, it being my earnest desire to point out to archæologists who are desirous of acquiring this knowledge, how easily they themselves may practise this beautiful art, and possess those objects they would desire to preserve, in a far more truthful state than could be otherwise accomplished.
I have not myself met that uniform success with any other paper that I have with Turner's photographic of Chafford Mills: a sheet of this divided into two portions forms at the same time a useful and also a very easily-managed size, one adapted for most cameras, forming a picture of nine inches by seven, which is adequate for nearly every purpose. Each sheet being marked in its opposite corners with a plain pencil-mark on its smooth side (vide _antè_, p. 372.), the surface for { 21} all future operations is in all lights easily discerned. In my instructions for printing from collodion negatives, a form of iodized paper was given, which, although very good, is not, I think, equal to the following, which is more easily and quickly prepared, exhibits a saving of the iodide of potassium, and is upon the whole a neater mode.
Take sixty grains of nitrate of silver and sixty grains of iodide of potassium; dissolve each separately in an ounce of distilled water; mix together and stir with a glass rod. The precipitate settling, the fluid is to be poured away; then add distilled water to the precipitate up to four ounces, and add to it 650 grains of iodide of potassium, which _should_ re-dissolve the precipitated iodide of silver, and form a perfectly clear solution; but if not, a little more must be carefully added, for this salt varies much, and I have found it to require 720 grains to accomplish the desired object.
The fluid being put into a porcelain or glass dish, the paper should be laid down upon its surface and immediately removed, and being laid upon a piece of blotting-paper with the wet surface uppermost, a glass rod then passed over it to and fro ensures the _total expulsion_ of all particles of air, which will frequently remain when the mere dipping is resorted to. When dry, this paper should be soaked in common water for three hours, changing the water twice or thrice, so as to remove all the soluble salts. It should then be pinned up to dry, and, when so, kept in a folio for use. I have in this manner prepared from sixty to eighty sheets in an evening with the greatest ease. It keeps good for an indefinite time, and, as all experienced photographers are aware, unless you possess good iodized paper, which should be of a _primrose_ colour, you cannot meet with success in your after-operations. Iodized paper becomes sometimes of a bright brimstone colour when first made; it is then very apt to brown in its use, but tones down and improves by a little keeping.