SPRINGS AND STREAMS 155 



113. SPRINGS AND STREAMS 



Streams may have their source from mere surface water 

 which collects in the valleys, or, as is more often the case, 

 from water which comes from beneath the earth and forms 

 what is called a spring. The water seems to come upward, 

 but in reality it is actually flowing downward from some 

 higher place. Springs, as a rule, contain comparatively pure 

 water, but there are many mineral springs which are used for 

 medicinal purposes. These latter contain various minerals 

 dissolved in the water, and are often very powerful in their 

 action upon the human system, and even harmful, if taken in 

 excess. 



The water of rivers is usually not as pure, for surface drain- 

 age carries much foreign matter into them, and a river, free 

 from waterfalls and rapids, soon becomes contaminated with 

 all sorts of refuse matter, and even disease germs. Very 

 often sewage of cities empties into rivers, rendering them 

 unfit for domestic purposes, unless purified by some of the 

 methods given in the preceding section. 



References : 



1. 1205 : 41-42. Wells and Spring Water. 



2. 1304:50-51. Rivers. 



3. 1601 : 179-180. The Effect of Atmospheric Pressure on 



Springs. 



4. 1702 : 59-64. Mineral Waters and Wells. 



5. 1703 : 43-45. Natural Water and its Impurities. 



6. 1710 : 62. River and Spring Water. 



7. 1901 : 222-224. Water and Disease. 



a. 1206 : 145-150. Springs and Artesian Wells. 



6. 1209 : 79-83. Springs, Mineral and Thermal, and Wells. 



c. 1305 : 195-201. Springs and Artesian Wells. 



