Dissolve with gentle heat, and add
| Cold saturated aqueous solution of picric acid | 200 | parts. |
Bring the mixture to the boiling point, and then place in a shallow vessel, covered with a glass plate, and leave it in full sunlight for a month or more. Filter, bottle, and add six drops of carbolic acid to each ounce of the mixture. It will keep indefinitely and improves with age. It requires filtering from time to time, as a gelatinous crimson mud tends to deposit from the solution.
Lithio-picrocarmine.—Prepared as follows:—
| Carmine | 2·5 | grms. | 10 | grs. |
| Saturated solution lithium carbonate | 100 | c.c. | 1 | oz. |
Dissolve, and add
| Saturated solution picric acid | 250 | c.c. | 2 1/2 | oz. |
Add a few drops of carbolic acid to each ounce.
It should stand a day or two in sunlight and then be filtered. It improves by keeping.