50 ESSENTIALS OF BACTERIOLOGY. 



Next placed in 1 to 500 solution of bichloride of mercury for 

 hour. Then in the steam-chest for | hour. 



In the meantime, a receptable is prepared for them. This is 

 called the moist chamber. 



FIG. 20. 



Moist chamber for potatoes. 



The moist chamber consists of two large shallow dishes, one, 

 the larger, as a cover to the other. 

 These dishes are washed in warm distilled water. 



FIG. 21. 



Method of slicing potato. (After Woodhead and Hare.) 



A layer of filter paper moistened with a 15 to 30 drops of 1 to 

 1000 bichloride is placed in the bottom of the glass dish. 



The operator now prepares his own hands, rolling up his coat 

 sleeves and carefully washing his hands, then taking a potato 



