The remaining operations may be conducted by daylight. The picture is fixed in a solution of soda hyposulphite made by dissolving 1 oz. hypo in 5 oz. water. After being thoroughly washed, the transparency must be toned in a saturated solution of mercury bichloride; the plate is immersed in this till the whitening action of the solution ceases; it is then removed and thoroughly washed. The plate is next immersed in a solution of ammonia, about 20 minims to the ounce. In this the picture will gradually reappear, and must be carefully watched that it may not get too dark. For this purpose the plate may be removed from time to time, and examined by transmitted light. The colour should be a rich sepia brown. When the proper effect is obtained, the ammonia solution must be washed off under the tap, and the plate dried. The picture will darken slightly in drying, for which allowance must be made. These should not be used for any other purpose.

Dr. Janeway's Table of the Solubility of Photographic Chemicals.

Made for the Society of Amateur Photographers of New York.

Abbreviations

6. soluble; ins. insoluble; sp. sparingly; m. moderately; v. very; aim. almost; dec. decomposed.

Chemicals.

Water.

Cold Alcohol

59° F.

212° F.

One part is soluble in

Parts.

Parts.

Acid, Citric .. ..........

0*76

0.6 3 1

V. s.

v. s. v. s. dec.

v. s

Gallic............

100

m. s.

Oxalic............

8

V. s.

Pyrogallic..........

3.5

V. s.

Tannic.............

6

V. s.

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

10.5

ins.

Chrome......................

10

ins.

Ammonium, Nitrate......

0.6

v. s.

v. s.

Chloride..................................

3

v.s.

sp. s.

Carbonate .. ..

4

dec.

m. s

Solphocyanate ..

V. ft.

V. 8.

v. s.

Bromide .. .. ••

1.5

0.7

sp. s.

Iodide.................................

1

0.6

m. s.

Baryta, Nitrate.....................

8

3

Cadmium, Bromide ......••

v. s.

V. s.

m. s.

Iodide......................

V. s.

V. s.

v. s.

Copper, Acetate.......................

16

6

sp. s.

Sulphate..................

2.6

0-6

Ins.

Gold, Chloride..................

V. s.

V. 8.

V. s.

Gold and Sodium Chloride.. ..

V. s.

V. s.

m.s.

Iron, Perchloride....................

V. s.

V. 8.

v. s

Protosulphate.................

1.8

0.3

ins.

and Ammonia sulphate

3

0.8

ins.

Iodide (Ferrous)

V. s

V. 8.

sp. s.

Iodine....................

7000

• •

m. s.

Kaolin........................

ins.

ins.

ins.

Lead, Acetate...........................

1.8

0.5

m.s.

Chloride.................

v. sp.

33

ins.

Nitrate..........................

2

0.8

Ins.

Lithium, Bromide..........................

V. s.

▼.8.

m. 5.

Iodide..............................

v. s.

v. a.

m. 5.

Magnesia, Nitrate..........................

v. s.

v. s.

m. s.

Mercury, Bichloride................

16

2

v. s.

Cyanide....................

12.8

3

ins.

Potassium, Acetate...........................

0.4

V. s.

v. s.

Chemicals.

Water.

Cold Alcohol

59° F.

212° F.

One part is soluble in

Parts.

Parts.

Potassium Bicarbonate.............

3-2

dec

ins.

Bichromate.........

10

1,6

ins.

Bromide...........

1.6

1

sp. s

Carbonate..................

1

0.7

ins.

Cyanide...................

2

1

m.s.

Ferricyanide ..

3-8

2

ins.

Ferrocyanide ..

4

2

ins.

Nitrate..............

4 .

0.4

ins.

Iodide................

0.8

0.6

m.s.

Oxalate........................

3

v.s.

ins.

Permanganate .. ..

20

3

ins.

Sulphate................

9

4

ins.

Sulphite.................

4

6

sp. 8.

Sulphide.............

2

1

sp. s

Silver Nitrate........

0.8

0.4

m.s.

Oxide..................

v. sp. s.

V. sp. s.

ins.

Sodium, Acetate...........

3

1

m.s.

Bromide..................

1.2

0.5

m.s.

Bicarbonate.....................

12

dec.

ins.

Carbonate................

1.6

0.25

ins.

Citrate...........

v.s.

v.s.

Sp.s.

Hyposulpahte..............

1

v. s

ins.

Iodide.......................

0 6

0.3

m.s.

Nitrate............................

1.3

0.6

sp. s.

Phosphate....................

6

2

ins.

Pyrophopate.............

12

1.1

Ins.

Sulphite...............

4

0-9

sp. s.

Sulphate.................

2.8

0.4

ins.

Tungstate................

4

2

ins.

Strontia, Chloride................

1-88

V.S.

sp. s.

Uranium, Nitrate...............

v.s.

V. s

m.s.

Zinc, Iodide................

v.s.

v. s.

m.s.

Bromide.......................

v. s.

v.s.

m. s.

Chloride.....................

0.33

v.s.

v. s.

Care there will be no bubbles. Allow the film to dry, and coat with plain collodion. When this is dry, run a sharp penknife 3/8 in. from edge of plate, and you have the gelatine film between 2 collodion films, impervious to moisture, quite flat, and may be printed from either side. The acid is so dilute that any developing tray may be used. (Photo. News.)