All living things need nitrogen in a form their bodies can use. It is important to plants and animals as well as to humans. It is a necessary part of the protein substance which is man’s body-building material. Without this substance, no one could grow or repair damaged or worn-out tissues.

While oxygen makes up only 21 per cent of the air we breathe, nitrogen makes up 78 per cent. There are about 7,200,000 tonnes of nitrogen above a square kilometer of the earth’s Surface. It is a colorless, odorless, tasteless gas that dissolves only slightly in water.