Page 48 - The Wellington photographic handbook

PYRO-SODA.'
No. 1.
Pyrogallic Acid 1 ounce 50 grammes
Sodium Sulphite (cryst.) ... 2 ounces 100
Citric Acid 40 grains 4-5 „
Water to 10 ounces 500 c.c.
No. 2.
Sodium Carbonate (cryst.) ... 8 ounces 100 grammes
Sodium Sulphite (cryst.) ... 8 „ 100
Water to 80 1 litre
Take 1 dram (4 c.c.) of No. 1, 1 ounce (30 c.c.) of No. 2, 5 minims (or
drops) of a 10% solution of Potassium Bromide, and dilute with water to
make 10 ounces (300 c.c.) in all.
The time of development at 65° Fahr. is 20 minutes.
If preferred the metol-hydrokinone formula given on page 33
may be used, each ounce of the solution being diluted with ten
ounces of water. At 65° Fahr. the time of development will be
fifteen minutes.

FIXING.
If the films have been developed in a tank, the instructions
for fixing issued with the apparatus should be carefully followed.
Films which have been developed in the length by hand, should
be passed several times through a dish of water before fixing.
It will be found convenient at this stage to cut the film up (rounding
the corners as mentioned above), and transferring the separate
negatives to the fixing bath.
FIXING BATH.*
Hypo ... ... 4 ounces 100 grammes
Water 20 „ 500 c.c.
On no account must the films be allowed to lie motionless,
one on top of another, while in the hypo. They must either be
laid out separately or must be kept moving, taking the one at the
bottom and placing it at the top and so on. The fixing should
be carried on until the whole of the white appearance at the back
of the film has disappeared and for as long again. Complete fixing
is as important as thorough washing.
* Before making up any formula, read the notes on pages 125, 126 and 134.
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