Food and water main eat to man. Fresh food pure water is necessity to the boy for good health.

Water is not only essential every day for drinking and but also useful cooking, bathing and washing. Water is a liquid. Its solid form is ice.

Water makes up about seventy percent of our body weight and about ninety percent of the blood. Water is essential for chemical reactions to occur in the body. It acts as a solvent for many substances. Thus water helps in the transport, absorption and secretion of substances in the body. It is also helps in removal of soluble waste- urea and excess salts from the body.

The water that is filter appears clean to look at. But it may still contain harmful bacteria, which cannot be seen by the eye. They can cause stomach problems and spread diseases like jaundice and typhoid. Boiling kills many of the bacteria in water. It is safe to drink boiled and cooled water.

It is not practicable to supply boiled water to the entire city through the water supply system. Chlorine gas mixed with water before it is supplied through taps. Chlorine kills most of the harmful bacteria and makes water safe for drinking.

A special types of light called ultra violet light, kills bacteria when it is passed through water. Many of the domestic filtered use this technique now. First water is filtered to remove floating impurities and then ultra violet is passed through the filtered water, before it comes out of the filter.

Tooth Pain down from the slat water.

Steam or water vapour is water in the gaseous form. Water dissolves most of the substance and forms a solution. Heating quickens the dissolution, more solute dissolves in hot liquid than in clod liquid. Water can be purified by; sedimentation, decantation and filtration.