Printing Process—Salting the Paper.—Boil the following mixture in an earthen vessel until it becomes transparent:—
| Distilled water | 12 | ounces |
| Muriate of ammonia | 240 | grains. |
| Arrowroot | 112 | grains. |
After this has been sufficiently boiled, it should be strained through clean linen or cotton cloth (free from soap or other substances), and, when cool, it is ready for coating the paper, which is done by dipping a new clean sponge into it and rubbing it over one side of the paper, giving it a uniform coating; but as it is not desirable to have too much on the paper, it should be rubbed with a clean sponge until nearly dry; it can then be hung up by the corner until thoroughly dry, when it can be put into a portfolio and kept for exciting for use.
Silvering Solution.—This solution may be prepared in the light, but must be used in a dark room:—
| Distilled water | 1 | pint. |
| Nitrate of silver | 3¾ | ounces. |
Dissolve and pour into an earthen or gutta-percha dish. Take the paper (cut to the proper size) and float it on this solution for about three minutes; care must be observed that there are no air-bubbles between the solution and the paper, for this would cause spots. It now can be hung up to dry, and as soon as dry it may be used. Let me here repeat, that this operation must be conducted in a dark room.
Fixing and Toning Bath.—I find that a better effect is produced if the positive be a little over-printed before being acted upon by the following mixture:—
| Distilled water | 8 | ounces. |
| Chloride of sodium | 240 | grains. |
This solution should be put into a flat dish and the print placed on it, face down, for from one and a-half to three minutes, when it should be taken off and put into the following solution, and allowed to remain there from three quarters of an hour to two hours:—