Page 126 - The Wellington photographic handbook

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DEVELOPING WELLINGTON LANTERN PLATES.
For cold tones the hydrokinone formula given on page 26
or the following metol-hydrokinone developer will be found
:—
satisfactory
METOL-HYDROKINONE DEVELOPER.
Metol 20 grains 1 gramme
Hydrokinone 60 3 grammes
Sodium Sulphite (cryst.) ... 700 „ 35
Sodium Carbonate (cryst.) ... 700 ,, 35
Potassium Bromide ... ... 6 ,, 0-3 gramme
Water to 20 ounces 500 c.c.
Dissolve in the order given, allowing each ingredient to enter completely
into solution before adding the rest. For use dilute with an equal part of
water.
N.B.—All metol-hydrokinone developers should be used at a temperature
of from 60° to 65° Fahr. Below 60° Fahr. hydrokinone rapidly loses its
developing power and at very low temperatures becomes practically inert.
In many cases, however, a tone warmer than that given by
the above developer is preferable, and for this purpose the following
pyro-ammonia developer is recommended :

PYRO-AMMONIA DEVELOPER.*
No. I.
Pyrogallic Acid 1 ounce 50 grammes
Sodium Sulphite (cryst.) 2 ounces. 100
Citric Acid 40 grains 5
Water to 10 ounces 500 c.c.
No. 2.
Ammonia -880 1 ounce 50 c.c.
Water to 10 ounces 500 c.c.
No. 3.
Ammonium Bromide 1 ounce 50 grammes
Water to 10 ounces 500 c.c.
The single solutions keep well, but should not be mixed together
until the developer is required for use. It is made by taking
thirty minims of No. 1, sixty minims of No. 2 and thirty minims
of No. 3, and adding one ounce of water (in metric measure, 30,
60 and 30 drops respectively may be taken to 30 c.c. of water).
This developer gives warm black tones, the slides being developed
in from two to two-and-a-half minutes.
If the quantity of No. 3 is increased, the rest remaining the
same, warmer tones are obtained, getting browner and browner
* Before making up any formula, read the notes on pages 1 26 and
1 25, 1 34.
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