Salt has been used from the very earliest times and in all parts of the world. Most of the salt now used comes from rock salt mines. Some salt is mined very much as coal is. A modern way of getting salt out of the mine, hundreds of feet beneath the surface of the earth, is by first drilling wells. Into these wells, or holes, are suck casings (metal linings.) Pure water is poured down the wells. When it reaches the bottom it dissolves the salt. Then the dissolved salt, or brine, is pumped up and put into vats like the ones in the view. Steam is being used to evaporate, or dry up, the water. When the water is all evaporated the salt remains. It is not yet ready to sell, for it is mixed with dirt and other substances. The salt must go through several processes to make it clean, pure and fine enough for our use. Then

it is ready to be packed and shipped. There are large salt mines in Michigan, New York, Ohio, Kansas, California and Louisiana. There are also valuable mines in many foreign countries. Salt is obtained by evaporation from the water of oceans and salt lakes. There is more salt in a gallon of salt lake water than there is in a gallon of ocean water. Salt is mostly used to season food. It also has many other uses. It is used to preserve meat and fish; for hardening soap; for making glass more clear; and it is a food for animals. Do you understand why it is used in freezing ice cream? In olden days salt helped develop trade routes. Places where salt could be obtained sometimes became battle grounds. In ancient Tibet cakes of salt were used for money.