TWO doctors lived without salt for a fortnight. At the end of that period, they could hardly speak, and they found it difficult to walk and breathe, they had lost about 6 kg. each in weight and their memory was almost gone. This shows how important salt is to our human system. During the year we eat about 10 pounds of salt Our blood has salt in it. When we sweat some of the salt forms on the surface of our skin. Then we must put back into the blood, the salt we have lost. from it. The more we sweat the more salt we lose and therefore the need to take in more salt.
For us salt is cheap. It is certainly not a precious mineral. But in some places salt used to be so scarce that it was used instead of money. The soldiers of ancient Rome once received their pay in the form of salt, and it is from this we get our word ‘salary’. Salary comes from the Roman word salarium’ which means salt money. There is plenty of salt in the world. Almost one fourteenth of sea water consists of salt. The common way to prepare salt is to let sea water flow into large shallow basins and allow the water to evaporate. The salt is left behind. It can be taken out when the basin has dried up. In some countries salt is mined just as coal is mined. In the salt mines men used to cut hard rocks of salt with pickaxes.
Most of the salt produced today is made from salt water, pumped out of wells. How is this done? A hole is drilled down into the earth in a place where rock salt is known to exist. The rock salt may be a thousand feet underground. When the rock salt is reached, fresh water is allowed to run down the holes. The rock salt dissolves in water and pure water becomes salt water. Then this water is pumped out to the surface. It is filtered and then boiled. As the water boils, it evaporates and pure salt is obtained.
Salt is necessary to keep man alive. Animals too need salt. Salt is also needed in industries. Salt can be broken into two substances. The chemist calls salt, sodium chloride, and can break it into sodium and chlorine.
Chlorine is useful in making our water supply safe to drink. Chlorine is also used in papermaking to bleach the paper white. It is also used in making sprays like D.D.T. which kill disease -carrying insects like mosquitoes and houseflies. These sprays also kill locusts. So, you can see that salt is common and yet is an especially useful mineral indeed!