Transparent spots in the negative are caused by air-bubbles forming on the plate when the developer is turned over it, and the bubbles not being broken, the developer does not have a chance to act on the film.
Larger spots on the plate or near the edge, which seem less intense than the rest of the negative, are caused by the plate not being covered all at once with the developer. The undeveloped plate should be placed in the tray and the developing solution turned over it quickly with a sort of sweeping motion, and the tray rocked in all directions till the plate is completely covered.
Never place a negative in sunshine or near a stove to dry. The heat causes the gelatine to melt and run off the plate. If for any reason one wishes to dry a negative quickly, wash it, after removing it from the hypo, for about half an hour, wipe off the water with a piece of damp surgeon's cotton, lay the negative in the tray, and cover it with alcohol. Let it remain in the alcohol for a minute or two, then take it out and set it up to dry. It will dry in from five to ten minutes, ready for printing.
Sometimes in warm weather the edges of the sensitive plate will come loose from the glass. This is called "frilling," and occurs when the developer is too warm. If the plate begins to frill, remove it to a dish of cold water, and lower the temperature of the developer by setting it for a few minutes in a dish of ice-water. The temperature of solutions should not rise above 85°, or sink below 65° if good results are desired.
In a later paper full directions will be given for retouching negatives, improving the high-lights, blocking out backgrounds, etc. But these belong to the finer part of the mechanical work of photography.
Sir Knight Glover Beardsley, Auburn, New York, asks: 1, if one can use a ruby light safely when putting a plate in the holder; 2, if a plate should be left in the water after being taken from the hypo, or if it can be washed off and put to dry at once; 3, in the formula for making blue prints, where it says add one and one-half ounce of citrate of iron and ammonium, if it means three-quarters ounce each, and does it mean the ammonium in a liquid or solid form. 1. One may use a ruby light with safety in filling plate-holders. It is wise not to hold the plate too near the light. 2. Negatives should be washed at least half an hour in running water, and one hour if one has not running water, changing the water four or five times. 3. "Citrate of iron and ammonium" is a double salt formed of ferric citrate and citrate of ammonium, and comes in brown shining leaflets. Ask for "citrate of iron and ammonium" when buying the ingredients for the formula.
Sir Knight A. Smith, Trenton, New Jersey, asks for a good developing solution, how to polish ferrotype plates, and how to keep films from curling when drying. Makers of dry plates always put in each box of dry plates formulas for developing, with full directions for preparation and use. These will always be found reliable. In No. 786 will be found a simple developer for instantaneous pictures, and we shall shortly publish a set of formulas with full directions for use. In Nos. 797 and 805 will be found directions for preparing a ferrotype plate so that prints will not stick. If the prints are trimmed before toning, they can be pasted before removing from the ferrotype, and thus most of the gloss made by the plate will be retained. Films may be kept from curling by soaking the film, after fixing and washing, in a solution of one-quarter ounce of glycerine and 16 ounces of water. Pin them at the corners to a flat board, removing all drops of water with a soft cloth. Set the board in an upright position till the films are dry. Do not use any more glycerine than the proportions given, as it will make the negatives sticky.
RECALLED STORMY TIMES.
"Well, that looks natural," said the old soldier, looking at a can of condensed milk on the breakfast-table in place of ordinary milk that failed on account of the storm. "It's the Gail Borden Eagle Brand we used during the war."—[Adv.]