140 AN INTRODUCTION TO SCIENCE 



cholera. There is such a thing as mischievous cleanliness. 

 It looks so immaculate that it withdraws attention from the 

 real source of danger. 



Fortunately, there is a treatment to which all microbes 

 are ready victims. They are easily killed by heat. None 

 can survive a temperature of 70 C., and boiling destroys all 

 kinds of spore. A boiled bacillus is an insignificant thing ; 

 but a live germ is more to be feared than a dead lion. 



