The picture, resting on caoutchouc, is immersed in a warm solution of gelatine.
| Gelatine, | 6 to 8 parts. |
| Glycerine, | 2 to 2½ parts. |
| Water, | 100 parts. |
As soon as all the air-bubbles have been removed, a piece of fine paper is immersed, and both the paper and the picture are removed from the dish by drawing them over the corner of the same; both are suspended and left to dry; they can then be easily trimmed, pressed on moist pasteboard, and separated by means of benzine.
Dr. Vogel has recently made the curious discovery also that carbon prints can be transferred without the use of gelatine. This process is much more simple than Swan's. The time which is gained by doing away with gelatinizing, drying, etc, etc., cannot be too highly estimated.
The operation is carried out in the Royal Academy at Berlin, in the following manner:
Common paper, as white and smooth as possible, is dipped for two minutes in cold water; it is then dried a little between blotting-paper, and the developed picture, after having been dried, is laid on it, picture side down, and smoothed over with the hand. After this, it is placed in the press, the moist sheet downwards, and on it a piece of felt. It is drawn once through the press, and suspended for drying. The rollers must work very evenly, or the pictures are apt to become wrinkled.
For small pictures, a copying press will suffice. The moist paper is placed upon blotting-paper, the picture is placed on top of this, it is pressed down a little with the hand, and then pressed in the press for about two minutes.
After drying for thirty minutes, the picture is dipped for one minute into a solution of chromate of alum, 1:300. After this, it is dried again. The time required
