I now coat a piece of glass half an inch larger all round than the negative with India rubber solution (see Eastman formula), and squeegee the negative face downward upon the rubber, interposing a sheet of blotting paper and oilskin between the negative and squeegee to prevent injury to the exposed rubber surface, and then place the negative under pressure with blotting paper interposed until moderately dry only.

I then pour hot water upon it, and, gently rocking the dish, you see the paper floats from the film without the necessity for pulling it with a pin, leaving the film negative on the glass. Now, the instructions say remove the remaining soluble gelatine with camel's hair brush, but, unless it requires intensifying, which no properly developed negative should require, you need not do so, but simply pour on the gelatine solution (see Eastman formula), well covering the edges of the film, and put on a level shelf to dry.

I will now take up a negative in this state on the glass, but dry, and carefully cut round the edges of the film, and you see I can readily pull off the film with its gelatine support. Having now passed through the whole of the process, it behooves us to consider for a few minutes the causes of failure in the hands of beginners and their remedies: 1. The rubber will not flow over glass? Solution too thick, glass greasy. 2. Rubber peels off on drying? Dirty glass. 3. Negative not dense enough? Use more bromide and longer development. 4. Gelatine cracks on being pulled off? Add more glycerine. 5. Gelatine not thick enough? Gelatine varnish too thin, not strong enough. 6. Does not dry sufficiently hard? Too much glycerine.—E.H. Jaques, Reported in Br. Jour. of Photography.

[1]

A communication to the Birmingham Photographic Society.

HOW DIFFERENT TONES IN GELATINO-CHLORIDE PRINTS MAY BE VARIED BY DEVELOPERS.

The following formulæ are for use with gelatino-chloride paper or plates. The quantities are in each case calculated for one ounce, three parts of each of the following solutions being employed and added to one part of solution of protosulphate of iron. Strength, 140 grains to the ounce.

Slaty Blue.
1.—One part of the above solution to three parts of a solution of citrate of ammonia.
Greenish Brown.
2.—Citric acid.180grains
Carbonate of ammonia.50"
3.—Citrate of ammonia.250grains.
Chloride of sodium.2"
4.—Citrate of ammonia.250grains.
Chloride of sodium.4"
Sepia Brown.
5.—Citrate of ammonia.250grains.
Chloride of sodium.8"
Clear Red Brown.
6.—Citric acid.120grains.
Carbonate of magnesia.76"
Warm Gray Brown.
7.—Citric acid.120grains.
Carbonate of soda.205"
Deep Red Brown.
8.—Citric acid.120grains.
Carbonate of potash.117"
Green Blue.
9.—Citric acid.90grains.
Carbonate of soda.154"
Citrate of potash.24"
Oxalate of potash.6"
Sepia Red.
10.—Citric acid.80grains.
Carbonate of soda.135"
Citrate of potash.12"
Oxalate of potash.3"
11.—Citric acid.108grains.
Carbonate of magnesia.68"
Carbonate of potash.12"
Oxalate of potash.3"
Sepia Yellow.
12.—Citric acid.40grains.
Carbonate of magnesia.25"
Citrate of ammonia.166"
13.—Citric acid.120grains.
Carbonate of magnesia.72"
Carbonate of ammonia.72"
Chloride of sodium.8"
Blue Black.
14.—Citric acid.120grains.
Carbonate of ammonia.70"
Carbonate of magnesia.15"
15.—Citric acid.120grains.
Carbonate of magnesia.38"
Carbonate of ammonia.44"
16.—Citric acid.90grains.
Carbonate of magnesia.57"
Citrate of potash.54"
Oxlate of potash.18"
17.—Citric acid.72grains.
Carbonate of magnesia.45"
Citrate of potash.54"
Oxalate of potash.18"
18.—Citric acid.60grains.
Carbonate of magnesia.38"
Citrate of potash.68"
Oxalate of potash.22"
A more Intense Blue Black.
19.—Citric acid.30grains.
Carbonate of magnesia.18"
Citrate of potash.100"
Oxalate of potash.33"
A Clearer Blue.
20.—Citrate of potash.136grains.
Oxalate of potash.44"

In the photographic exhibition at Florence, the firm of Corvan[1] places on view a frame containing twenty proofs produced by the foregoing twenty formulæ, in such a way that the observer can compare the value of each tone and select that which pleases him best.—Le Moniteur de la Photographie, translated by British Jour. of Photo.