Carmine.—It is made as follows:—
| Carmine (best) | 2 | 1 | drachm. |
| Strong ammonia | 2 | 1 | drachm. |
| Distilled water | 100 | 6 | ounces. |
Rub the carmine with a little water in a mortar, add the ammonia, when the liquid will turn black. Gradually add the rest of the water, rubbing it up all the time. It should be bottled, allowed to stand for a few days, and then filtered, and a piece of camphor put in the bottle.
Lithium carmine resembles closely ammonia carmine in its staining effects. It is usually a matter of individual preference which is employed.
| Carmine | 2 1/2 | grms. | 10 1/2 | grs. |
| Saturated aqueous solution of lithium carbonate | 100 | c.c. | 2 | ozs. |
Dissolve and filter.
Sections may be sufficiently stained in either of these fluids in from three to five minutes, but more satisfactory results are to be obtained by diluting with twenty times the bulk of distilled water, and leaving sections to stain for twenty-four hours.
After staining in carmine the sections must be passed through a half per cent. solution of acetic acid, in order to fix the carmine in the tissues, as otherwise the water will dissolve the stain out.
Borax carmine—