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*-- (_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. Boil for twenty minutes. Filter. Add a few drops of carbolic acid. In using this reagent it should be filtered into a watch glass, and the sections placed in it for at least an hour. There is no fear of overstaining, and they may be left all night. After they have been stained they must be _thoroughly_ washed in water to remove the alum, otherwise numerous crystals of it will be seen in the field when the section is mounted. Sections may be mounted in Farrant’s solution or in Canada balsam. The staining effect improves very much after the section has been kept a few days.