THE GENERAL PROBLEM OF KEEPING WELL 395 



Avoidance of Germ Diseases. The problem of prevent- 

 ing diseases caused by germs is an exceedingly difficult 

 one and no solution for all diseases has yet been found. 

 One's chances of avoiding such diseases, however, may be 

 greatly enhanced : 



1. By strengthening the body through hygienic living so 

 that it offers greater resistance to the invasions of germs. 



2. By living as far as possible under conditions that are 

 unfavorable to germ life. 



3. By understanding the agencies through which disease 

 germs are spread from person to person. 



Conditions Favorable and Unfavorable for Germs. Con- 

 ditions favorable for germ life are supplied by animal and 

 vegetable matter, moisture, and a moderate degree ot 

 warmth. Hence disease germs may be kept alive in damp 

 cellars and places of filth. Even living rooms that are 

 poorly lighted or ventilated may harbor them. Water 

 may, if it contain a small per cent of organic matter, sup- 

 port such dangerous germs as those of typhoid fever. 

 Fresh air, sunlight, dryness, cleanliness, and a high temper- 

 ature, on the other hand, are destructive of germs. The 

 germs in impure water, as already noted (page 165), are 

 destroyed by boiling. 



How Germs are Spread. Some of the more common 

 methods by which the germs of disease are spread, and by 

 so doing find new victims, are as follows : 



1. By Means of Foods. Foods, on account of the 

 locality in which they are produced or the method of 

 gathering or of handling them, may become contaminated 

 with germs, which are then transported with the foods to 

 the consumer. 



2. By Means of Dust. Material containing germs, 

 e.g., discharges from the throat and lungs, will on drying 



