C.—To sixteen ounces of Plain Collodion add from eight to twelve drops of tincture of iodine (50 grains of dry iodine dissolved in half an oz. of alcohol) and 14 grains or drops of fluoride of ammonium; shake the mixture well; then add all of the solution B; shake it again and thoroughly; after this has stood for twenty-four hours it can be used, but will be found better after it has been prepared one week.
Nitrate of Silver Solution.
| Pure rain or distilled water | 64 | ounces. |
| Nitrate of silver (in crystals) | 4¼ | ounces. |
| Clean pure white sugar | 75 | grains. |
| Six grains of iodide of ammonium dissolved in half a drachm of alcohol. | ||
The above, thoroughly mixed and allowed to stand for a few hours, should be filtered through a new clean sponge, asbestos, or Swedish filtering paper, and then a few drops of nitric acid, chemically pure, should be added, just enough to redden blue litmus-paper; then it is ready for use, and will improve by age.
Developing Solution.—This formula has proved very satisfactory in my hands, and I hope will be equally so with all who give it a trial:—
| Water | 1 | pint. |
| Boracic acid | ¾ | ounce. |
| Protosulphate of iron | ¾ | ounce. |
| Pulverized nitre | ½ | ounce |
| Three drops of oil of cinnamon dissolved in two ounces of alcohol. | ||
Dissolve and filter, and it is ready for use. It is better to make this developer fresh every other day.
Dissolving off the Iodide of Silver.—Water, about half a pint; cyanide of potassium, enough to clear the impression in about thirty seconds—say a quarter of an ounce.
Fixing the Impression.—I use the article well known to every good photographer as Humphrey's Collodion Gilding, and it serves the purpose better than anything that I I know of.