CHAPTER VII 

 THE RELATION OF WATER TO HEALTH AND DISEASE 



The human body contains nearly 60 per cent of 

 water. Some of the individual organs, as the kidneys, 

 heart, liver and pancreas, contain a much larger propor- 

 tion, and all are dependent on a sufficient supply of it 

 for the proper performance of their functions. 



The human race in its very infancy sought out the 

 springs and streams that yielded a generous supply of 

 cool, refreshing water; it made its home within reach of 

 them; it followed the water-courses to the sea, loath to 

 lose sight of them; and, as it grew in wisdom, it learned 

 to find in them food as well as drink. Long before the 

 dawn of written history, men knew of the life-giving 

 qualities of water, and of its often deadly effects. Ex- 

 perience taught them to preserve it against periods of 

 scanty rainfall, to guard it against pollution, to measure 

 it out with a careful hand to the thirsting crops. 



Ancient water-supplies. — In selecting their source of 

 drinking-water, the ancient builders of reservoirs and 

 aqueducts were guided by considerations of quality 

 and salubrity. It was known to them and to others 

 before them that there is some relation between drink- 

 ing-water and health and disease. Certain springs 

 were peculiarly noted for their reputed curative proper- 



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