Take 1/2 oz. of this solution and immerse a piece of litmus paper in it, which will turn red; now add, gradually, enough of a saturated solution of soda bi-carbonate to restore the litmus to its original colour; now to 24 oz. of filtered water add the neutralised gold, and a very small pinch of sodium chloride (common table salt); stir thoroughly, and your bath is ready. For simplicity and excellence this cannot be surpassed.
After washing the prints in two changes of water, they are immersed one at a time in the toning bath; a dozen or more can be toned at the same time if you are careful to keep them in motion by changing them during the process of toning. Leave them in this bath until they assume a deep purple; if fixed at this stage, the result will be a warm sepia, which will dry out a neutral tone; do not carry the toning until the prints lose their brilliancy. Generally about 15 minutes is ample, but will vary according to the temperature and amount of goll in the bath.
Prints fixed without toning give a very artistic and pretty effect, producing a result not unlike a photogravure in tone and general eflect.
The prints are fixed in soda hyposulphite 1 oz., water 8 oz , for 15 minutes. They should then be washed in running water for two hours.
After drying, trim, then lay them one on the other, and place a heavy weight on them overnight, the next morning the prints will lie perfectly flat. Now procure some heavy, stiff, white paper, and have it cut large enough to allow a good margin when mounted. For example, a 9 x 11 mount for a 5 x 8 print. Mount by simply sticking the corners. - (W. S. Waterbury.)