[DRY-PLATES THAT WILL DEVELOP WITH WATER.]
Some time ago dry-plates were placed on the market which would develop, apparently, with water and a little ammonia only. The secret of the method was that the backs of the plates were coated with a soluble gum, containing the developing agents, and, of course, when the plate was immersed in the water, they instantly dissolved and formed the developer. Plates thus prepared are useful in traveling where it is not always possible to get the necessary developing solutions. To prepare them the backs are coated with the following mixture:
| Pyrogallic acid | 154 | grains |
| Salicylic acid | 15 | grains |
| Gum or dextrine | 154 | grains |
| Alcohol | 1 | fluid dr. |
| Water | 5 | fluid dr. |
This is allowed to dry at an ordinary temperature. After exposure, all that is necessary to develop is to immerse the plates in water containing a small quantity of ammonia.
[CARICATURE PHOTOGRAPHS.]
There are quite a number of different methods of making caricature portraits. A simple one is to make two photographs of an individual, one of the head alone and another of the entire body on a much smaller scale. From these two negatives prints are made, and the larger head is cut out and pasted on the shoulders of the full length figure. Any signs of the cutting out are removed by the use of a brush and a little coloring matter. From this combined print another negative is made so that any number of these caricature prints can be made without extra trouble. The effect is shown in Fig. 44.
