44 APPLIED BACTERIOLOGY FOR NURSES 



Arnold steam sterilizer. This consists of a very shallow 

 boiling pan, a steam chamber, which is surrounded by 

 the removable hood, and a large pan, which catches the 

 drip water. The large pan is connected with the small 

 pan by a number of small openings, thus constantly 

 keeping a supply of water in the boiling pan. The ad- 

 vantage of this design is the rapidity with which steam 



Fig. 20. Arnold steam sterilizer (Fowler). 



is developed and the little attention the apparatus 

 requires when in operation. The temperature within 

 the steam chamber is approximately that of boiling 

 water, 212 F. This form of sterilizer is extensively 

 used to sterilize the various nutrient media used for 

 growing bacteria. In order to be certain that steriliza- 

 tion has been complete it is customary to sterilize these 



