44 



METHODS OF STERILISATION 



2. Remove the cotton-wool plug from the neck of 

 the filter flask and adjust the porcelain candle in its 

 place. 



FIG. 36. Screw clamps. 



3. Attach the nozzle of the separatory funnel to the 

 filter candle by means of the perforated rubber stopper 

 (Fig. 37)- 



FIG. 37. Apparatus arranged for filtering aspiration. 



4. Open the tap of the funnel, and exhaust the air 

 from the filter flask and wash-bottle; maintain the 

 vacuum until the filtration is complete. 



5. When the filtration is completed close the tap of 



