Use the regular A and B Pyro - Acetone solutions taking:

1 ounce A ......

...... 30 c.c.m.

4 ounces B......

...... 120 c.c.m.

2 ounces water.. .

...... 60 c.c.m.

Adding thereto 2 to 3 drams (8 to 10 c.c.m.) of a 10 per cent, solution of bromide of potassium.



Rinse developed plates thoroughly to avoid carrying developer into the fixing bath and place in the following:

Acid - Fixing - and Hardening Bath.


- Water (1 gallon).......

128 ounces

4 litres

Hypo-Sulphite of Soda. . . .

32 ounces

1 kilo

(Which will test about 80 degrees by hydrometer.)


- (See note below.) Water....

32 ounces

1 litre

Cramer's Dry Sulphite Soda.

3 ounces

90 grams

(Which will test 45 degrees by hydrometer.)

Sulphuric Acid C. P......

1/2 ounce

15 c.c.m.

Powdered Chrome Alum....

2 ounces

60 grams

Note. - Be sure to mix solution B exactly in given proportion and rotation. Always pour B into A while stirring well. If this is not done precipitation will take place.

During the cold season one-half the quantity of solution B is sufficient for full quantity of solution A.

B can also be prepared as follows:


. 32 ounces

1 litre

Potassium Meta bi - sulphite.

3 ounces

90 grams

Powdered Chrome Alum. . .

2 ounces

60 grams

This bath remains clear after frequent use, does not discolor the negatives, and hardens the film to such a degree that the negatives can be washed in warm water and dried by artificial heat if necessary. They should be left in the bath ten to twenty minutes after the bromide of silver appears to have been dissolved, to insure permanency, freedom from stain, and perfect hardening.

If the bath becomes exhausted by continued use, replace it by a new one.

Plain Fixing Bath.


. 32 ounces

1 litre

Hypo - Sulphite of Soda. ..

8 ounces

250 grams

(Which will test about 80 degrees by hydrometer.)

Do not use the bath when it is discolored, it must be made fresh each day.