CHAPTER IX 



WATER AND OTHER BEVERAGES 



WATER is indispensable for animal life, since no food 

 can be absorbed and utilized by tlie body unless it is 

 in solution. Because of its power to dissolve substances, 

 natural water is never found pure, although fortunately 

 its impurities are not usually harmful. Ordinarily, 

 water contains in solution oxygen, carbon dioxide 

 and traces of such salts as nitrates, chlorides and car- 

 bonates. 



Mineral contents. When water contains much lime 

 or other carbonate, it will not readily dissolve soap 

 and it is therefore said to be hard. Most spring and well 

 waters become charged with carbon dioxide from decay- 

 ing vegetation in the upper layers of the soil. The pres- 

 ence of the carbon dioxide gives them the power of dis- 

 solving carbonates from the soil as they filter through it 

 and they are consequently apt to be hard. Surface 

 waters, on the contrary, especially rain water, are rela- 

 tively soft, as are also distilled waters. For drinking 

 purposes, neither the very hard nor yet the soft pure 

 distilled waters are good, since the hard waters contain 

 an objectionable amount of carbonate, while distilled 

 water is so pure that it is irritating to the stomach. 

 The best water for drinking, therefore, is one that is 

 neither very hard nor very soft but contains a moderate 

 amount of air in solution together with a moderate 

 amount of carbonates and other earthy salts, including 



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