_B._ Ferric Alum (Ferric
Ammonium Sulphate) 4 lbs. 2 ozs. 2000 grams
Potassium Bromide 2 lbs. 2 ozs. 1000 grams
Hydrochloric Acid
(concentrated) 13 ozs. 400 cc.
Water to 50 gals. 200 liters
_Time of Toning_
Toning should be complete in from 3 to 5 minutes.
_Time of Washing_—Ten to fifteen minutes.
If the highlights are stained blue, or if the image will not
completely tone in the shadows, this is due to _insufficient washing
after bleaching_. When bleaching, it is important to examine the film
as little as possible, otherwise streaks are liable to be produced
due to the action of the air at those parts where the solution
drains off the film. It is also important to tone immediately after
bleaching and washing.
_Life of Baths_
Bleach A.
Providing the solution is screened from the light and kept covered
to prevent the undue escape of ammonia, the bath keeps fairly well,
but if it shows any signs of weakening, it should be revived by the
addition of a further quantity of ammonia equal in amount to that
originally used. If so revived at intervals, 50 gallons will bleach
40,000 feet of film before exhaustion.
Solution B.
Fifty gallons of solution B will tone 30,000 feet of film without
further addition of acid, when it should be thrown away.