| C. IRON CHLORATE SOLUTION |
|---|
| Solution B | 100 parts |
| Potassium chlorate | 0.4 part |
| D. MERCURIC SOLUTION. |
|---|
| Mercuric chloride solution at 5:100 | 20 parts |
| Sodium oxalate solution at 3:100 | 40 parts |
| Glycerine | 2 parts |
| SENSITIZING SOLUTIONS. |
|---|
| FOR BLACK TONES. |
|---|
| Platinite solution, 1:6 | 5 parts |
| Solution B | 6 parts |
| Solution C | 2 parts |
| FOR SEPIA TONES. |
|---|
| Platinite solution, 1:6 | 5 parts |
| Solution C | 4 parts |
| Solution D | 4 parts |
Intermediate tones are obtained by diminishing the dose of C and replacing it by an equal volume of B. For this process the paper should be sized with
| Arrowroot | 2 parts |
| Sodium oxalate at 3:100 | 100 parts |
To dispense with this preliminary sizing Captain Pizzighelli adds gum arabic to the platinite solution, whereby the sizing and sensitizing are done in one operation.
The gum arabic solutions are prepared as follows:
| E. | Gum arabic in powder | 40 parts |
| Sodium ferric oxalate solution, B | 40 parts |
| Sodium oxalate solution at 3:100 | 100 parts |
| Glycerine | 3 parts |
Place the glycerine and the gum arabic in a mortar, then, stirring with the pestle, dissolve by adding, little by little, the mixture, heated to 40—45 deg. C. (104—113 deg. Fahr.), of the solution of sodium ferric oxalate and sodium oxalate. Let stand for about two hours and grind again to dissolve entirely the gum arabic. Filter through muslin.