124 DISINFECTION— STERILIZA TION— DISINFECTANTS 



in an autoclave of the tj'pe shown in Fig. 74 it required ten 

 minutes for 500 cc of water at 15 pounds' pressure to reach 

 a temperature of 100°, starting at room temperatures, 20° to 

 25°. Autoclaves may be used as simple steam steriHzers by 



Fig. 77.- 



•Horizontal steam chest used in canning, 

 width, 28 inches; length, 10 feet. 



Height, 32 inches; 



leaving the escape valves open so that the steam is not 

 confined, hence they have largely replaced the latter. ^ 



1 In the author's laboratory all sterilization except those few objects in 

 blood and serum work which must be dry, is done in autoclaves of the 

 type shown in Fig. 75, which are supplied with steam from the University 

 central heating plant. A very great saving of time is thus secured. 



