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PRINCIPLES AND PRACTICE OF DISINFECTION AND STERILIZATION. 
Physical agents. 
1. Sunlight — 
Expose spores of anthrax, subtilis, etc. 
Expose nonspore-bearmg 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 slips and cultures to various currents. 
Expose to electric light. 
Expose to X-rays. 
3. Dryness and dry heat — 
Expose slips, or threads with spore-bearing and nonspore-bearing organisms to : 
a. Dryness at room conditions. 
b. Dry in incubator at 37° C. 
c. Dry over sulphuric acid. 
d. Dry heat at 60° C., 
100° C., 
150° C., 
for variable times. 
€. Expose paper slips saturated with — 
a. Decomposing urine, 
b. Sewage, 
c. Garden earth, 
to 150° C. for one hour to test power of sterilization of this temperature. 
Hot-air sterilizer. 
Note. — P lant in bouillon and keep one week for growth. 
5. Moist 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. 
6. Theory, mechanics, and practical application of steam in — 
a. Koch steamer. 
b. Arnold steam sterilizer. 
c. Autoclave (steam under pressure). 
d. Steam chamber (steam under pressure). 
Make practical tests in each. 
