Photographing On Silk.
| Sodium chloride | 4 parts |
| Arrowroot | 4 parts |
| Acetic acid | 15 parts |
| Distilled water | 100 parts |
Dissolve the arrowroot in the water by warming gently, then add the remaining ingredients. Dissolve 4 parts of tannin in 100 parts of distilled water and mix the solutions. Let the silk remain in the bath for 3 minutes, then hang it carefully on a cord stretched across the room to dry. The sensitizing mixture is as follows:
| Silver nitrate | 90 parts |
| Distilled water | 750 parts |
| Nitric acid | 1 part |
Dissolve. On the surface of this solution the silk is to be floated for 1 minute, then hung up till superficially dry, then pinned out carefully on a flat board until completely dry. This must, of course, be done in the dark room. Print, wash, and tone in the usual manner.
Toning Baths For Paper.
The chief complaints made against separate baths are (1) the possibility of double tones, and (2) that the prints sometimes turn yellow and remain so. Such obstacles may easily be removed by exercising a little care. Double tones may be prevented by soaking the prints in a 10 per cent solution of common salt before the preliminary washing, and by not touching the films with the fingers; and the second objection could not be raised provided fresh solution were used, with no excess of sulphocyanide, if this be the bath adopted.
A very satisfactory solution may be made as follows:
| Sodium phosphate | 20 grains |
| Gold chloride | 1 1/2 grains |
| Distilled (or boiled) water | 10 ounces |
This tones very quickly and evenly, and the print will be, when fixed, exactly the color it is when removed from the bath. Good chocolate tints may be obtained, turning to purple gray on prolonged immersion.