BACTERIOLOGY. 65 



Cleanliness is an efficient weapon to 

 Cleanliness, employ against bacteria. Too much can- 

 not be said in its^ favor. Through it we 

 can dispose of the most essential factor in the growth 

 of bacteria, namely, organic matter. Where organic 

 matter does not exist, bacteria cannot live and multiply. 

 Material of any kind, containing bacteria, is said 

 to be septic; when free from bacteria, aseptic. In 

 practical work, e.g., surgery, objects and persons are 

 rendered bacteria-free either through the use of antisep- 

 tics and disinfectants, or by mechanical cleansing with 

 soap and water. The two methods are distinguished 

 as the antiseptic, and aseptic methods respectively. 



