CHAPTER XIII 

 THE PRESERVATION OF HEALTH 



444. The Teachings of Modern Hygiene. Modern hygiene 

 not only formulates rules for the preservation of health, 

 but it goes much farther and treats of the prevention of disease. 

 It warns us of the unseen and invisible foes which assail 

 our health at every moment and teaches us the best meth- 

 ods to check the prevalence of disease. Even if we obey 

 every law of hygiene, we cannot, of course, wholly avoid 

 these invisible enemies, but it is none the less true that 

 there is a power in every healthy human body that may 

 successfully battle the germs of disease. This power is 

 best conserved and developed by living up to the best 

 hygienic standards. 



BACTERIA 



445. Nature and Propagation of Bacteria. The words 

 bacteria, bacilli, germs, micro-organisms, and microbes are terms 

 commonly applied to certain low forms of plant life of 

 microscopic size. 



If some finely chopped hay be covered with water and 

 set in a warm place for a few days, and a few drops of the 

 liquid are examined under a high power of the microscope, 

 the water is found to be swarming with various forms of 

 living organisms, chiefly bacteria. 



These microscopic plants belong to the great fungus 

 division. They consist of many varieties, which may 



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