Now pass one end of the platinum wire through the hole, turn up about 2 mm. at right angles and press the short piece into the short cut. Turn the long end of the wire sharply, also at right angles, and sink it into the long channel so that it emerges from about the centre of the cut end of the aluminium wire (Fig. 63). A few sharp taps with a watch maker's hammer will now close in the sides of the two channels over the wire and hold it securely. [Illustration: FIG. 64.--Platinum rod in aluminium handle--method of mounting. The platinum wire may be fused into the end of a piece of glass rod, but such a handle is vastly inferior to aluminium and is not to be recommended.] 8. Two pairs of sharp-pointed spring forceps (10 cm. long), one of which must be kept perfectly clean and reserved for handling clean cover-slips, the other being for use during staining operations. 9. A box of clean 3 by 1 glass slips. 10. A glass capsule with tightly fitting (ground on) glass lid, containing clean cover-slips in absolute alcohol. 11. One of Faber's "grease pencils" (yellow, red, or blue) for writing on glass. 12. A wooden rack (Fig. 65) with twelve drop-bottles (Fig. 66) each 60 c.c. capacity, containing Aniline water. Gentian violet, saturated alcoholic solution. Lugol's (Gram's) iodine. Absolute alcohol. Methylene-blue, } Fuchsin, basic, } saturated alcoholic solution. Neutral red, 1 per cent. aqueous solution. Leishman's modified Romanowsky stain. Carbolic acid, 5 per cent. aqueous solution. Acetic acid, 1 per cent. solution. Sulphuric acid, 25 per cent. solution. Xylol. [Illustration: FIG. 65.--Staining rack, rubber change mat and lysol pot.] [Illustration: FIG. 66.--Drop bottle.] [Illustration: FIG. 67.--Canada balsam pot.] And two pots with air-tight glass caps (Fig. 67), each provided with a piece of glass rod and filled respectively with Canada balsam dissolved in xylol, and sterile vaseline. METHODS OF EXAMINATION. Bacteria, etc., are examined microscopically. 1. In the living state, unstained, or stained. 2. In the "fixed" condition (i. e., fixed, killed, and stained by suitable methods). The preparation of a specimen from a tube cultivation for examination by these methods may be described as follows: ~1. Living, Unstained.~--(a) _"Fresh" Preparation._-- 1. Clean and dry a 3 by 1 glass slip and place it on one of the squares of filter paper. Deposit a drop of water (preferably distilled) or a drop of 1 per cent. solution of caustic potash, on the centre of the slip, by means of the platinum loop. [Illustration: FIG. 68.--Holding tubes for removing bacterial growth, as seen from the front.] TECHNIQUE OF OPENING AND CLOSING A CULTURE TUBE.