Bottle Wax.
Bleaching Photographic Prints White.
| Bichloride of mercury | 1 ounce |
| Water | 5 ounces |
| Alcohol | 1 ounce |
| Hydrochloric acid | 1 drachm |
If the drawing has been made with non-waterproof ink, then alcohol is substituted for the water in the formula. For safety, use an alcoholic solution of mercury. The bleaching solution is poured on and off the drawing, and, when the print is bleached white, the mercury is washed off the drawing by holding it for a few moments under running water. Photographs bleached in this way will keep white for years.
To Render Negatives Permanent.
Stripping Photograph Films.
Phosphorescent Photographs.
According to Professor Schnauss, plates for phosphorographs are prepared as follows: Dissolve 10 parts of pure gelatin in 50 parts of hot water, add and dissolve 30 parts of “light” color (as above), and 1 part of glycerine.
If a plate or a paper, prepared as above detailed, be placed under a diapositive, in a copying apparatus, and submitted to the action of sunlight for a few minutes, when taken out in a dark room a phosphorescent picture of the diapositive will be found. It is also a known fact that duplicate negatives or positives may be made with this phosphorograph by simply bringing the latter in contact in a copying apparatus, with the ordinary silver bromide plate for 30 seconds, in the dark room, and then developing the same.