THE TONING BATH.
Tone in a plain gold bath, using about i gr. of gold to 48 ozs. of water. Neutralize by adding a saturated solution of borax, bi-carbonate of soda or sal soda.
This should be made up at least one-half hour before using ; this gives the chemicals a chance to harmonize. When making the toning bath, first measure the water and pour into the tray or dish you are to use, then add the gold. Now take a piece of red Litmus paper (this is very sensitive to acid or alkali) and place in the solution. Then add the borax solution drop by drop (this is a strong alkali and should be kept in a bottle, the cork of which has a small slit in it allowing the solution to drop, not run out) just enough to turn the Litmus paper blue in five minutes. This will make the bath almost neutral, i. e., slightly alkaline. The bath is now ready for use. Should the prints tone fast in the high lights, or light parts of the prints, leaving the shadows, or dark parts, very red, and when finished have a muddy (not clear) appearance, that indicates that you have used too much borax or alkali. On the other hand, had the Litmus paper remained its original color (red) that would indicate that the bath was acid and that you had not used sufficient alkali. \Vith the bath in that condition your prints would not tone but bleach, lose their brilliancy and become flat.
When toned, immerse prints in running water where they may remain until all are ready for the fixing.
If running water cannot be had put prints into Salt,- - - - - - i oz.
W - Water, - - - - r gal.
If there is a large batch of prints to be toned do not allow prints to lie in short stop solution, but put them into a tray containing clear water where they may remain until all are ready for the fixing.
Fix twenty minutes in Water, - - - - - f gal.
- - Hypo, - - 13 ozs.
Solio Hardener, - - - - I 2 OZ.
To mix with Hydrometer, take water 1 g-al., add sufficient Hypo to test 25 gr. to the oz. and add 7-, oz. of Solio Hardener.
On account of its simplicity and cheapness, we advise the Solio Hard ener Fixing Bath, but give the alum fixing bath for the benefit of those who prefer it.
Hypo-sulphite of Soda, - - - 6 ozs.
Alum (Crystals), 2 OZS.
Sulphite of Soda (Crystals), oz.
\\ ater, - 7o ozs.
When dissolved add 3_( oz. of borax dissolved in io ozs. hot water, This fixing bath must be made about io hours before use. As it keeps indefinitely before use it may be made up in large quantities.
After fixing in one of the foregoing baths, wash hour in running cold water or in 16, changes of cold water, keeping prints separated so the water may have a chance to eliminate the chemicals.
The toning bath should tone in 6 or 7 minutes.
Tone by transmitted light for the high lights and half tones only, pay ing no attention whatever to the shadows.
We recommend a neutral bath and advise the use of Squibb's red litmus to test with.
If the bath tones uneven or streaky, add water until it tones in S or io minutes, and make it slightly alkaline.
One gallon of fixing bath is sufficient for one gross 4 x 5 size Solio or its equivalent.
Prints allowed to stand over night in water are liable to turn yellow ; they should therefore be mounted as soon as washed.
To make Solio Hardener : Chloride of Aluminum, - 3 ozs.
Pi-Sulphite of Soda, - 212 OZS.
Cold Water, 12 ozs.
Put both chemicals in the water and shake until dissolved.