Iodized Albumen.
| White of egg (free from yelk) | 10 | ounces. |
| Honey | 1 | ounce. |
| Iodide of calcium | 2 | scruples. |
| Yeast | 1 | tablespoonful. |
Mix these together in a tall glass jar, or wide-mouthed bottle of at least one pint capacity; tie a piece of paper, pierce with small holes over the top to keep out dust; then place the whole near a fire or other warm situation, where the temperature is not lower than seventy degrees, or higher than ninety degrees. In a few hours fermentation commences, which is evident by the formation of bubbles of gas, rising through the liquid. This action continues for five or six days; when it ceases, pour the whole on a paper-filter contained in a funnel, underneath which must be placed a bottle to receive the liquid as it passes through. The fluid being of a viscid nature filters slowly, generally occupying twelve hours.
The filtered liquid is the "iodized albumen," which is said by Dr. Taupenot to keep good for years. It must be carefully preserved from dust or contact with any substance, as the success of the picture depends materially on the condition of this albumen.
Albumen Bath Solution.
| Nitrate of silver | 1 ounce and a half. |
| Acetic acid, glacial | 1 ounce. |
| Distilled water | 16 ounces. |
| Animal charcoal | 2 drachms. |
Dissolve the nitrate of silver in the distilled water, then add the acetic acid and animal charcoal, and keep in a closely stoppered bottle for use.
Pyrogallic Solution.
| Pyrogallic acid | 15 | grains. |
| Glacial acetic acid | 2 | drachms. |
| Alcohol | 2 | drachms. |
| Distilled water | 7 | ounces. |
Dissolve the pyrogallic acid in the distilled water, and then add the acetic acid and alcohol.