56 ESSENTIALS OF B ACTERrOLOGY. 



in the (lame a second to singe the cotton plug, and the plug 

 removed, the edges of the tube again flamed, the bell-glas.s 

 lifted, and the inoculated gelatine carefully poured on the plate, 

 leaving about one-third inch margin from the borders ; the lips 



FIG. 27. 



Nivellicr leveling and cooling apparatus. 



of the tube being sterile can be used to spread the media evenly. 

 If the plate is at all cool, the fluid will solidify as it is being 

 spread. The glass cover is replaced until the 'gelatine or agar 

 is quite solid to prevent contamination. 



FIG. 28. 



Moist chamber with plates on benches. 



When the gelatine is congealed, the plate is placed upon a 

 little glass bench or stand in the moist chamber. 



The Moist CJmmbcr Prepared Out of Two Glass Dishes, as for 

 tJie Potato- Culture*. Then glass benches are so arranged that 

 one stands upon the other. In order to avoid confusion, a slip 

 of paper with a number written on it is placed on the bench be- 

 neath each plate. As the original or first plate would have the 

 colonies developed in greatest profusion, it is placed the first 



