=Oil of Cloves= is used as a clearing fluid for sections preparatory to mounting in Canada balsam. =Canada Balsam= is used as a permanent mounting medium for dehydrated specimens, and as a cement for ringing slides. =Paraffin= is used for general embedding and infiltrating. =Lugol’s Solution= is used as a test for starch and for aleurone grains and proteid matters. =Osmic Acid=. A two per cent solution is used as a test for fixed oils. =Alcohol, Glycerine, and Water Mixture= is used as a temporary mounting medium and as a qualitative test for fixed oils. =Chlorzinc Iodide= is used as a test for suberin, lignin, cellulose, and starch. =Analine Chloride= is used as a test for lignified cell walls of bast fibres and of stone cells. =Phloroglucin=. A one per cent alcoholic solution is used in connection with hydrochloric acid as a test for lignin. =Hæmatoxylin-Delifields= is used as a test for cellulose. [Illustration: FIG. 38.--Reagent Set] REAGENT SET Each worker should be provided with a set of =reagent bottles= (Fig. 38). Such a set may be selected according to the taste of the individual, but experience has shown that a 30 c.c. bottle with a ground-in pipette and a rubber bulb is preferable to other types. In such forms the pipettes are readily cleaned, and the rubber bulbs can be replaced when they become old and brittle. The entire set should be protected from dust by keeping it in a case, the cover of which should be closed when the set is not in use. MEASURING CYLINDER In order accurately to measure micro-chemical reagents, it is necessary to have a standard 50 c.c. cylinder (Fig. 39) graduated to c.c.’s. Such a cylinder should form a part of the reagent set. [Illustration: FIG. 39.--Measuring Cylinder] STAINING DISHES [Illustration: FIG. 40.--Staining Dish] There is a great variety of =staining dishes= (Fig. 40), but for general histological work a glass staining dish with groves for holding six or more slides and a glass cover is most desirable. CHAPTER VI HOW TO MOUNT SPECIMENS The method of procedure in mounting specimens for study varies according to the nature of the specimen, its preliminary treatment, and the character of the mount to be made. As to duration, mounts are either temporary or permanent. TEMPORARY MOUNTS