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PRINCIPLES AND PRACTICE OF DISINFECTION AND STERILIZATION. 
Physical agents. 
1. Sunlight — 
Expose spores of anthrax, subtilis, etc. 
Expose nonspore-bearing organisms as typhoid, diphtheria, etc., to the sunlight 
in thin films and for penetration. Note intensity of the light, temperature, 
dryness, and other conditions. Plant in bouillon. 
2. Electricity — 
Expose shps and cultures to various currents. 
Expose to electric light. 
Expose to X-rays. 
3. Dryness and dry heat — 
Expose shps, or threads with spore-bearing and nonspore-bearing organisms to: 
a. Dryness at room conditions. 
h. Dry in incubator at 37° C. 
c. Dry over sulphuric acid. 
d. Dry heat at 5° C., 
' 15° C., 
37° C., 
for various times. 
e. Expose paper slips saturated with — 
а. Decomposing urine, 
б. Sewage, 
c. Garden earth, 
to 150° C. for one hour to test power of sterilization of this temperature. 
Hot-air sterilizer. 
Note. — Plant in bouillon and keep one week for growth. 
4. Hoist heat — hot and boiling water and steam: 
Expose typhoid, diphtheria, and other nonspore-bearing organisms to 50°, 60°, 
70°, 80°, and 100° C. moist heat for variable times; plant in bouillon. 
Expose anthrax, subtilis, and other spores to 70°, 80°, 90°, and 100° C. moist 
heat for variable times; plant in bouillon. 
5. Theory, mechanics, and practical application of steam in — 
а. Koch steamer. 
б. Arnold steam sterihzer. 
c. Autoclave (steam under pressure). 
d. Steam chamber (steam under pressure). 
e. Superheated steam. 
iNIake practical tests in each. 
