The albumen mixture is then laid on to the paper by means of a flat camel's-hair brush, about three inches broad, the mixture being first poured into a cheese plate, or other flat vessel, and all froth and bubbles carefully removed from the surface. Four longitudinal strokes with such a brush, if properly done, will cover the whole half-sheet of paper with an even thin film; but in case there are any lines formed, the brush may be passed very lightly over it again in a direction at right angles to the preceding. The papers should then be allowed to remain on a perfectly level surface until nearly dry, when they may be suspended for a few minutes before the fire, to complete the operation. In this condition the glass is but moderate, and as is generally used; but if, after the first drying before the fire, the papers are again subjected to precisely the same process, the negative paper will shine like polished glass. That is coated again with the albumenizing mixture, and dried as before.
One egg, with the ounce of water, &c., is enough to cover five half-sheets with two layers, or five whole sheets with one.
I rarely iron my papers, as I do not find any advantage therein, because the moment the silver solution is applied the albumen becomes coagulated, and I cannot discover the slightest difference in the final result, except that when the papers are ironed I sometimes find flaws and spots occur from some carelessness in the ironing process.
If the albumenized paper is intended to be kept for any long time before use, the ironing may be useful as a protection against moisture, provided the iron be sufficiently hot; but the temperature ought to be considerable.
To render the paper sensitive, I use a hundred-grain solution of nitrate of silver, of which forty-five minims will exactly cover the sheet of seventeen inches by eleven inches, if laid on with the glass rod. A weaker solution will do, but with the above splendid tints may be produced. As to the ammonio-nitrate of silver, I have totally abandoned its use, and, after many careful experiments, I am satisfied that its extra sensitiveness is a delusion, while the rapid tendency of paper prepared with it to spoil is increased tenfold.
The fixing, of course, modifies considerably the tone of the proof, but almost any desired shade
may be attained by following the plan of Mr. F. M. Lyte, published in "N. & Q.," provided the negative is sufficiently intense to admit of a considerable degree of over-printing.
It is a fact which appears to be entirely overlooked by many operators, that the intensity of the negative is the chief agent in conducing to black tones in the positive proof; and it is almost impossible to produce them if the negative is poor and weak: and the same observation applies to a negative that has been over-exposed.
Geo. Shadbolt.
Cement for Glass Baths.—The best I have tried is Canada balsam. My baths I have had in use five years, and have used them for exciting, developing hypo. and cyanide, and are as good as when first used.