140 GENERAL SCIENCE 



water in such localities. Campers often contract dis- 

 eases from the use of surface water, river water, and 

 sometimes even from springs or from a near-by well. 

 There are several ways in which these dangers can be 

 avoided. The garbage of the camp should either be 

 burned, buried, or carried quite a distance from the 

 camp to prevent flies from collecting in great numbers. 

 A place where there are no mosquitoes should also be 

 selected. If water is taken from a running stream, it 



A HILLSIDE CUT BY THE ACTION OF WATER 



should be boiled before using it. Water taken from a 

 well or spring should be tested before using, and if germs 

 are found the water should be boiled. If there is no 

 well or spring near, but a large stream, a well can be 

 driven in a few hours near this stream and a pump put 

 into the driven well. The well, of course, will have to be 

 driven lower than the water in the stream. The water 

 from the stream will filter through the sand and gravel 

 into the well, which will usually be free from disease 

 germs. 



94. Water a Solvent. Rain water is slightly acid, 

 which enables it to dissolve more easily the rocks and 



