When fixed, which is judged by transmitted light, place in your washing-tank, or a dish, cardboard and upon sheets of insoluble gelatine and collodion combined; but, as yet, such have not been brought into general use.

Full instructions for using the films are given in the notes below. They entail quite a variety of changes in manipulation, and also cause and pass running water over for fifteen minutes, or give four or five changes of water at intervals of ten minutes.

Drying. - Provide yourself with, say, half a dozen clean glasses (a size larger than the negatives), which should he wiped on both sides with an oiled rag and subsequently rubbed quite dry. Your negatives can now be drawn on to the glass, face down, one on either side, and squeezed with a velvet rubber squeegee, which may be had of any dealer. Set up in a rack in the air, and they will dry rapidly; then remove by a touch.

Oiling. - Make a pad of manilla paper (say six thicknesses); on this lay your negative, face down, and smear the back with castor oil; use plenty of oil - a dessertspoonful at least to every 5x8 negative. Now, with a polishing iron with rounded edges, such as is used in laundries (quite hot), smooth the negative with a uniform pressure, following the path of the iron with a sponge or rag saturated with the oil. Proper oiling will be indicated by a uniform dark color all over the back; no spots or mottling should be seen; if any are seen, continue heating and rubbing on oil till they disappear.

Retouching may be accomplished from either side, and takes with great readiness.

Printing is done by placing on a clean glass in the printing - frame, after rubbing off all surplus oil, and, if it needs it, removing with a tuft of cotton and alcohol any greasiness on the surface, being careful, however, to allow none of the spirit to get on the back. - David Cooper.

When thoroughly fixed, which is shown by the negative being of a uniform color, looking through it, or simply showing the grain of paper with no opaque spots, wash and immerse in a saturated solution of alum for five minutes. Wash thoroughly and squeegee face down on a sheet of ebonite. When thoroughly dry it will peel off, giving a beautiful glossy face. (I prefer using the alum solution after fixing, as it gives a clearer and cleaner negative than when mixed with the hypo.) The negative will invariably curl face in on being lifted from the ebonite, and may be straightened by the scraping action of a ruler applied to the back.

Lay the negative on a sheet of glass with a piece of clean paper between the negative and glass. Apply the ruler, the corner behind the ruler being lifted as the ruler is passed along. When straight, lay face down on a piece of smooth pine board (with a piece of clean paper on it), and tack the four corners with thumb tacks. Apply the " translucine " or oil, and hold over the oil-stove, keeping the negative in motion till it presents a uniformly dark color all over. (The board keeps the negative from curling, as It would do if not tacked to the board when heat is applied.) When cool repeat the operation. I repeat it because one is then sure it is transparent, and it takes but a moment to do it. When cool the second time, wipe off the surplus oil with a clean rag. They can be retouched from either side. If from face, I apply the retouching fluid with the ball of the finger, same as with a glass negative. If from back no preparation is necessary; simply use a harder pencil.

I keep the negative in place in the printing-frame by tacking the corners with small pieces of gummed paper. For copies they are immense, as one can do four times the amount of retouching that can be done on glass - working out backgrounds, etc. In storing away for 24 the negative maker to hit upon some new plan of storing the treasures of his camera, because films cannot be held in racks or in ordinary negative boxes used for glass.

They should be kept flat and under pressure.

future use I oil a piece of paper in the same way I oil a negative, and place it between two negatives (back to back). This keeps the negatives saturated a long time, not allowing them to dry out. It is easier to oil the separating paper, than it is to have to re-oil two negatives. For all sizes from 5x7 up, they are grand. For enlarging with bromide paper they require about three times as long an exposure as a plate - W. B. Glines, in the Philadelphia Photographer.

For Eastman's Negative Films I find that the best formula for devoloping is that given by Mr. Eastman in his instructions; here it is:

No.1 - Sulphite of Soda

6 ounces

Distilled or Boiled Water

1quart

Pyrogallic Acid

1ounce

Dissolve the sulphite first, and then add the pyro.

No.2- Carbonate of Soda(pure)

1/4 pound

Water ... ......

. 1 quart.

To develop, pour into a clean tray the following:

No.1

1 ounce.

No.2

1"

Water

. 1 "

Immerse the exposed film in a tray of clean, cold water, and with a soft camel's-hair brush gently remove the air-bells that cling to the surface of the film. As soon as limp, remove the film to the developing-tray, and proceed with the development the same as with a dry plate. I go over the film with a camel's-hair brush whilst in the developer, and I think the result pays for the little extra trouble incurred. The image should commence to appear in ten or fifteen seconds. If the light comes out slowly, and with no detail in the shadows, add, not to exceed one ounce, of No. 2. If the image appears too quickly, add from ten to twenty drops of the Restrainer. -

Bromide of Potassium..................

1 ounce.

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

6 ounces.

Keep this in a dropping - bottle, consisting of an ordinary bottle having two notches cut lengthwise in the cork on opposite sides.

The film may be examined from time to time by transmitted light by holding it up by the corners. When sufficient density is obtained, wash the film in two or three changes of water, and then immerse in the Fixinq-Balh. -

Hyposulphite of Sodium..................

4 ounces.

Water.........

1 pint.

Mix fresh fixing - baths for each batch of negatives. Use no alum in fixing - bath, or, indeed, at any time with these films.

The want of a means to do this has already been supplied by the ingenious device of Mr.Frank G. Dubois,an amateur photographer - a closed case with interior contrivances, by the help of which the film negatives or unmounted prints from them may be filed away "alphabetically" and on their edges , kept clean under pressure, and in shape for easy finding.