Bromide Papers. The methods of printing, as detailed in Lessons M to S, inclusive, all remain about the same, with little or no changes. The new departure has been in the direction of permanent bromide paper, which is extremely sensitive, and, because of its matt surface, is preferred by the "aesthetic" printer. Another thing in its favor, besides the ease with which it may be printed, is the facilities it offers for enlarging upon it from small negatives. The paper is obtainable in sheets and in continuous rolls, ready sensitized. The prints may be made in any sort of light - even by moonlight. After exposure under the negative, the finishing is done by development as detailed below.

The extreme sensitiveness of this paper has been utilized by science in divers ways: medicine uses it to ascertain the presence of subtle poisons, observatories to register the atmospheric changes, which previously it had not been possible to do, etc. In photography it is certain that it can on the glass by the collodion) and press out all surplus water with a rubber squeegee; place in a rack to dry. When dry, run a knife around the edge and lift the film from the glass. It will be found to be perfectly flat, and will remain so. The collodion acts as a varnish.

By using ground-glass for preparing the gelatine skins a matt surface is given, and so one gets a splendid tooth for retouching if any is required, and it also softens the prints. If a matt surface is not wished, then the skins should be prepared upon plain glass. When attaching the skin to the negative film, be careful to place the glazed side next the film.

An objection may be raised to the use of collodion. If so, all that would have to be done would be to wax the temporary glass support with the following solution:

Yellow Beeswax..................

1 drachm.

Benzole..................

3 ounces.

Then proceed as though the plate had been collodionized. I prefer the collodion because it acts as a varnish for the negative. - " Kehama," in The Philadelphia Photographer.

373. Last week I made several 20 x 24 prints from negatives of about two inches with a Ross C D. V. lens, smallest stop, exposure ranging from 8 to 25 seconds. They can be made with an oil light, but the exposure would be of course so much longer, according to the brilliancy of your light.

Any one who has not a lantern, can easily fit up an apparatus which will answer the purpose just as well, with considerably less expense. I made one with a packing box, a condenser, a coal-oil lamp, and a few carpenter's tools.

But I think the best result, if you do not want to enlarge to more than 10 x 12, is by the negative process, which I will now proceed to describe.

The most important part of this method is the transparency from which to make the negative. My experience, which extends over many years, has proved to me that this transparent positive should be the full size you wish the enlargement to be. In the first place, it is all important that it should be fully exposed, the least trace of underexposure being fatal to good results. Next, it should be developed in very weak solution, and certainly not hurried in render great service when it is necessary to produce a great number of prints in a short space of time. One can, in a few minutes , produce alone, by gaslight, forty prints from the same negative. The paper is placed under a negative in the pressure frame, exposed to gas or any other light, developed with oxalate and iron, then fixed. The operation lasts from five to six minutes, whatever may be the number of prints.

Thus obtained, these prints, although strong, have the softness of a crayon drawing, together with photographic delicacy and preciseness.

For enlargements, also, the gelatino-bromized paper has considerable value. With the ordinary processes, several difficult operations are development; and the development should be pushed till there are very few points of bare glass, and those only in the highest lights. The developer I used for the transparency I have here, was made up as follows:

No.1 - Carbonate of Potassium.............................

3ounces.

Water...................

12 ounces

No.2 - Sulphite of Soda...................

4 ounces

Citric Acid...................

60 grains

Bromide of Ammonium...................

40 grains

Pyrogallic Acid...................

1ounce.

Water...................

12 ounces.

Of these two solutions, I use equal parts at the rate of one drachm of each to four ounces of water. If it should act too quickly upon the exposed plate, a few drops of a 60 grain solution of bromide of ammonium are added. If not quite enough, a few drops of the potassium solution and more water are added. It is, as I have said, best to expose fully and develop hourly with plenty of water. When finished, fix in fresh hypo, and, after washing for a few minutes, clear in the following solution:

Alum...................

1 ounce.

Citric Acid...................

1 "

Sulphate of Iron...................

3 ounces.

Water...................

20 ".

Let it stay in this from thirty seconds to two minutes, till all yellow color is gone; wash well in running water for at least one hour.

Having got the transparency the size you wish your enlarged reproduction to be, you must make your negative by contact. The first objection to that will be that you cannot get actual contact, the glass upon which the average dry plate is made being anything but flat. If the exposure is made in diffused light, that objection would be fatal, the loss of sharpness being very considerable where contact has not taken place. But my method is this: I put the transparency into the holder face inwards, then place a dry plate upon it, film side, of course, against the film side of the transparency, adjusting the camera with the lens pointing toward a window, and put between the window and the lens a sheet of ground-glass; pull out the bellows to the fullest extent, and put in the holder with the transparency and sensitive plate. You have now through your lens direct rays of light of more or less intensity, according to the stop used, and can in this way time your exposure to a nicety; and although your plates indispensable to obtain an enlarged print. First, it is necessary to print by contact or to enlarge slightly, either a gelatino-bromized, or chlorized, plate, or collodion plate, or a positive by transparency, from which is obtained a large negative to be used in printing; finally, the enlargement, either with carbon or on albuminized paper. With gelatino-bromized paper all these operations are done away with. It is the little negative itself that gives the enlarged picture Of course, an enlarging camera is necessary.

And yet, albumen - paper printing will always have its adherents - unless, indeed, a substitute be found that will closely imitate its results.