| (a) | Borax | 4 | grms. | 3 | drachms. |
| Carmine | 2 | grms. | 1 1/2 | drachms. | |
| Distilled water | 100 | c.c. | 5 | ounces. |
Dissolve with the aid of heat and add slowly to (b).
| (b) | Alcohol | 70 | c.c. | 3 1/2 | ounces. |
| Distilled water | 30 | c.c. | 1 1/2 | ounce. |
Allow to stand for a fortnight. Filter, and add a lump of camphor.
To use it, place sections, or the tissue in bulk, in it for from four to twenty-four hours, according to size, and then transfer to alcohol (seventy per cent.) containing a drop to the ounce of hydrochloric acid, for twenty-four hours, and then wash thoroughly in water. The tissue may then be placed in gum if it is to be frozen, dehydrated in alcohol if paraffin or celloidin is to be employed.
Its advantage is that it is very diffusible, and so can be used to stain tissues in bulk. It takes a considerable time to stain sufficiently deeply, but there is little fear of overstaining.
It stains nerve-cells and axis cylinders brightly, and also the connective tissue, bringing a sclerosed patch out very prominently.
Alum carmine:—
| Alum five per cent. solution in distilled water | 100 | c.c. | 1 | oz. |
| Pure carmine | 1 | grm. | 4 1/2 | grs. |