WATER 



435 



Flask containing 250 c.c. sterile broth. 



Test-tube brush to fit the lumen of the candle, enclosed in a 

 sterile test-tube (and previously sterilised by dry heat or by 

 boiling) . 



Case of sterile pipettes, 10 c.c. in tenths. 



Case of sterile pipettes, i c.c. in tenths. 



FIG. 209. Water filtering apparatus, That portion of the figure to the left 

 of the vertical line is drawn to a larger scale than that on the right, in order 

 to show details of Sprengel's pump. 



Case of sterile pipettes, i c.c. in hundredths. 



Tubes of various nutrient media (according to requirements). 



Twelve Buchner's tubes with rubber stoppers. 



Pyrogallic acid tablets. 



Caustic soda tablets. 



METHOD. 



. i . Fit up the filtering apparatus as in the accom- 

 panying diagram (Fig. 209), interposing the wash- 



