Saturated alcoholic solution of fuchsin 1 part Anilin water (see below) 10 parts Mix and filter. These stains rarely keep longer than ten days in the laboratory (unless kept in the ice-box) and must be made fresh on the first sign of a deposit on the glass of the container. =Anilin Water.=--Anilin water is made by putting 3 or 4 cc of anilin “oil” in a 120 cc. flask, adding 100 cc of distilled water, shaking vigorously for a minute or so and filtering through a wet filter, in other words, a saturated solution of anilin in water. 4. Löffler’s (methylene) blue. Saturated alcoholic solution of methylene blue 3 parts Aqueous solution of NaOH (or KOH), 1 to 10,000 10 „ Mix and filter. 5. Carbol-fuchsin (Ziehl’s solution). Saturated alcoholic solution of fuchsin 1 part 5 per cent. aqueous solution of carbolic acid 10 parts Mix and filter. 6. Gabbet’s (methylene) blue (solution). Dry methylene blue 4 parts Concentrated H₂SO₄ 25 „ Distilled water 75 „ Dissolve the dry dye in the acid and add the solution to the distilled water and filter. [Illustration: FIG. 140.--Author’s staining set. Square bottles are set in square holes in the block. The capacity of each bottle is 30 cc.] Staining solutions are conveniently kept in square dropping bottles inserted in a block as shown in Fig. 140. This form of holder necessitates the use of _one hand only_ in securing the stain and dropping it on the preparation. The actual staining of bacteriological preparations can be learned only by repeated laboratory practice, yet the following methods have given such uniform results in class work that it is felt they are not out of place in a text-book. =Preparation of the “Film.”=--The author learned to stain bacteria, on the “cover-glass” but does not recall having used this method in fifteen years and does not teach it to his students. All staining is done on the slide. To prepare a film from a solid culture medium the procedure is as follows: