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The Barnet Book of Photography A Collection of Practical Articles

Mix three parts by measure of A and one part of B

Hypo 2 ounces Water 20 ounces

After fixing (no matter what developer has been used) the prints must be thoroughly washed in several changes of water for at least two hours.

The chief reasons against the use of ferrous oxalate are lack of control over development and the necessary use of an acid bath. Unless the acid bath is used, the prints will be yellow because of the iron in them, and if the acid is not entirely removed before fixing the prints will be yellow owing to the decomposition of the hypo by the acid in the print which causes deposition of sulphur.

_Metol Developer._--With this, and the other developers I shall mention, an acid bath is not necessary and so one cause of failure (and extra work) is obviated. I have somewhat amended the Barnet formula to meet the needs of workers on a small scale and have also arranged A and B to balance each other without disturbing the relative proportions of the ingredients.

A. Metol 120 grains Water (cold) 24 ounces

Dissolve _completely_ and then add

Sodium sulphite 2-1/2 ounces Potassium bromide 15 grains

Shake until completely dissolved but do not apply heat.

B. Potassium carbonate 350 grains Water 8 ounces

For use, mix three parts by measure of A and one part of B.

With this developer and a normal exposure, the image should appear in a few seconds and development should be complete in about two minutes. As fast as the prints are developed they should be immersed in

Salt 2 ounces Water 20 ounces

to stop development. When all are developed, they must be rinsed for a minute or two in clean water and then fixed. Over-exposure is remedied by the addition of potassium bromide solution (as in the case of ferrous oxalate); under-exposed prints should be developed in a weak solution such as

A 3 parts B 1 part Water 4 parts

Development will take longer, but the weaker solution will help to bring up the detail without the harshness of the shadows that would be the case if the normal developer was used.

_Hydroquinone and Eikonogen._--The advantage of combining eikonogen with quinol lies in the fact that one provides what the other lacks, the eikonogen tending to give detail without density and the quinol (in inexperienced hands) giving density without detail. The following formula will be found very satisfactory:--

A. Quinol 40 grains Eikonogen 120 " Sodium sulphite 480 " Citric acid 20 " Water to 20 ounces

Dissolve the sodium sulphite and citric acid in 15 ounces of water, then add the other ingredients and enough water to make a total bulk of 20 ounces.

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