The History of Baths

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History of Water Through the Ages Part 1

"Waters," was the common normative description of water until it took its singular form about two hundred years ago. In its history it has been described as lethal, (floods), therapeutic (hydropathy), a food solvent (grain was the first breakfast cereal) a pharmaceutical substance, (cure). The modern definition of water has only been applied for two hundred years, a chemical compound, with dissolved or suspended minerals, gases and microorganisms. As a substance composed of the chemical elements hydrogen and oxygen, it exists in gaseous, (steam) liquid, and solid (ice) states. Historically it has shaped our planet both as water and as ice; it has affected our climate and atmosphere. Although the molecules of water, hydrogen and oxygen are simple in structure the physical and chemical, properties of the compound are extraordinarily complicated. Its melting point, 0 °C (32 °F), and boiling point, 100 °C (212 °F), are much higher than would be expected by comparison with compound of a similar structure, such as hydrogen sulphide and ammonia. Ice is its solid form and it becomes less dense than when it is liquid, another unusual property.

The water molecule is not linear but bent in a particular way the result of which is that part of the molecule is negatively charged and the other part is positively charged. Hydrogen atoms in water molecules are attracted to the areas of high electron density and can form hydrogen bonds, or weak links with those regions. This means that the hydrogen atoms in one water molecule are attracted to the non-bonding electron pairs of the oxygen atom on an adjacent water molecule.

As a result, water molecules associate strongly within an ice crystal, the association is a highly ordered but has a loose structure. When the ice melts, this logical arrangement partially breaks down and the molecules pack more closely together. This explains why the liquid is denser than the solid, and why ice forms on top of liquid water. The associative force, is strong enough to prevent water molecules from separating completely even at room temperature. This continued association in the liquid state means that water has a high boiling point. The structure of liquid water is believed to form and re-form continually and accounts for other unusual properties of water, such as its high viscosity and surface tension. To a limited extent, water dissociates into positively charged hydrogen (H+) ions, which make a solution acidic, and hydroxyl negatively charged (OH-) ions, which make it alkaline (basic). Consequently, water can act as an acid or a base.

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