All glassware used in the bacteriological laboratory must be thoroughly cleaned before use, and this rule applies as forcibly to new as to old apparatus, although the methods employed may vary slightly. ~To Clean New Test-tubes.~-- 1. Place the tubes in a bucket or other convenient receptacle, fill with water and add a handful of "Sapon" or other soap powder. See that the tubes are full and submerged. 2. Fix the bucket over a large Bunsen flame and boil for thirty minutes--or boil in the autoclave for a similar period. 3. Cleanse the interior of the tubes with the aid of test-tube brushes, and rinse thoroughly in cold water. 4. Invert the tubes and allow them to drain completely. 5. Dry the tubes and polish the glass inside and out with a soft cloth, such as selvyt. ~New flasks, plates, and capsules~ must be cleaned in a similar manner. ~To Clean New Graduated Pipettes.~-- 1. Place the pipettes in a convenient receptacle, filled with water to which soap powder has been added. 2. Boil the water vigorously for twenty minutes over a Bunsen flame. 3. Rinse the pipettes in running water and drain. 4. Run distilled water through the pipettes and drain. 5. Run rectified spirits through the pipette and drain as completely as possible. 6. Place the pipettes in the hot-air oven (_vide_ page 31), close the door, open the ventilating slide, and run the temperature slowly up to about 80° C. Turn off the gas and allow the oven to cool. Or 6a. Attach each pipette in turn to the rubber tube of the foot bellows, or blowpipe air-blast, and blow air through the pipette until the interior is dry. Glassware that has already been used is regarded as _infected_, and is treated in a slightly different manner. ~Infected Test-tubes.~-- 1. Pack the tubes in the wire basket of the autoclave (having previously removed the cotton-wool plugs, caps, etc.), in the vertical position, and before replacing the basket see that there is a sufficiency of water in the bottom of the boiler. Now attach a piece of rubber tubing to the nearest water tap, and by means of this fill each tube with water. 2. Disinfect completely by exposing the tubes, etc., to a temperature of 120° C. for twenty minutes (_vide_ page 37). (If an autoclave is not available, the tubes must be placed in a digester, or even a large pan or pail with a tightly fitting cover, and boiled vigorously for some thirty to forty-five minutes to ensure disinfection.) 3. Whilst still hot, empty each tube in turn and roughly clean its interior with a stiff test-tube brush. 4. Place the tubes in a bucket or other convenient receptacle, fill with water and add a handful of Sapon or other soap powder. See that the tubes are full and submerged. 5. Fix the bucket over a large Bunsen flame and boil for thirty minutes. 6. Cleanse the interior of the tubes with the aid of test-tube brushes, and rinse thoroughly in cold water.