The drinking warter

‘Drinking water,’ once wrote Leonardo da Vinci, ‘can be health-giving, unwholesome, laxative, sulphurous, mournful, angry, red, yellow, green, black, blue, greasy, fat and thin.’
The water you drink today probably has few of these qualities. But even in our day about half a billion people are said to be constantly sick because of the water they drink. Ten million of them may die each year.
Surprisingly, even developed nations that take pride in their “safe” water are now having problems. Modern farming and industry are introducing a growing list of hard-to-remove and potentially hazardous chemicals into drinking-water sources. “It seems that everything that makes life easier makes water dirtier,” noted one U.S. expert at Senate hearings on the problem.
Life Depends on It
Despite these problems, water remains one of the most marvelous and absolutely essential substances known. The very existence of life itself on earth is based on it. In fact, water is the main ingredient of most living things. The human body has been described as a “virtual walking sack of precariously contained fluids.” About two thirds of your total weight is water, while as much as three fourths of your brain and muscles are.
From this it is obvious that life functions best within the narrow temperature range in which water exists as a liquid. Such an environment where life could exist is said to be practically nonexistent elsewhere in the universe. Though scientists speculate about possible millions of planets in the universe, the book Water: The Web of Life marvels: