56 



Our Surroundings 



is broken up into small particles or drops. In this manner, the 

 sunlight and air, which kill germs, come in contact with the 

 water. This process is called aeration. 



Some other cities treat their water with chlorine gas. Such a 

 small amount of chlorine is used that one cannot even taste it in 



Keystone View Co. 



AERATION OF WATER 



Spraying water into the air so that sunlight and fresh air will purify it. 



the water, but it is sufficient to kill any germs that may be present. 

 This process is called chlorination. 



Mineral Springs. A hole in the ground or a crevice in a 

 rock, from which water flows naturally, is called a spring. The 

 original source of spring water is rain on land higher than the 

 springs. The water flows along beneath the soil until it comes to 

 the surface at some lower point. When the land through which 



