CHAPTER III. 
THE DESTRUCTION OF BACTERIA, STERILIZATION 
AND DISINFECTION. 
The knowledge of the means by which bacteria 
are destroyed underlies the methods employed in dis¬ 
infection, sterilization, and antisepsis as they are used 
in preventing the spread of infection. The term dis¬ 
infection means the total destruction of bacteria by 
any agent, while sterilization is limited to the destruc¬ 
tion of. bacteria by heat. An antiseptic is a chemical 
agent that prevents the growth and multiplication of 
bacteria, but does not necessarily destroy them. A 
deodorant is a substance that masks offensive odors 
or substitutes an agreeable odor for a disagreeable 
one. Some of the disinfectants and antiseptics are also 
deodorants, but few of the deodorants have disin¬ 
fectant properties. 
The agents that affect bacteria injuriously may 
be physical or chemical. Among the physical agents 
may be mentioned drying, light, and heat. 
Drying prevents the growth of bacteria and will 
eventually destroy them. The spores of bacteria, how¬ 
ever, will resist drying for a much longer time. It is 
for this reason that the bacterial content of dust is 
chiefly in the form of spores. The effect of drying is 
influenced by the temperature at which the drying 
2 ( 17 ) 
Defini¬ 
tion of 
disinfec¬ 
tion 
Sterili¬ 
zation 
and anti¬ 
sepsis 
Physical 
agents 
Drying 
