WHERE SALT COMES FROM
The Arab, journeying over the yellow sands, riding upon the back of his faithful "ship of the desert," often looks longingly for some sign of water to cool his parched lips. The sailor may ride upon the beautiful blue waters of the ocean in his white-winged ship; but although there is nothing but water to greet his eyes, he cannot drink it, for it is bitter to the taste.
If you were to place a quantity of ocean water over a fire and evaporate it, there would remain a white substance. This is common salt. You see that it is as necessary to provide fresh water when one wishes to cross the ocean, as it is if one is going to cross the desert.
Most streams and lakes contain fresh water, so you will wonder why the waters of the ocean are briny. The rocks and soil of the earth contain salt, and the streams wash it from the land. Each one carries so little that we do not notice it, but they have worked so steadily and so long, that they have carried a great amount to the sea. None of it can escape, so the ocean gets more and more briny.
No healthy person would ever think of eating salt alone as a food, and yet our food would taste very unsatisfactory without it. Farmers supply their cattle and horses with salt, and wild animals search for it in the forests, and lick it from the soil with their tongues.
Salt is so important to us that I want to tell you about some of the ways in which men obtain it.
Sometimes sea water is placed in great vats and evaporated. This leaves the salt, which is then refined. You know that the sun's heat causes the waters of a shallow pond to evaporate during warm weather. Shallow basins are often scooped out along the coast, and the waters which fill them are then shut off from the larger body. In time the water evaporates, and the salt, which has formed in thin layers, is collected.
I said that most lakes are fresh-water bodies. There are some, however, that are very salty. Great Salt Lake is one of these. Streams flow into it, but none flows out. If you were to bathe in the waters of this lake, you would find that your body would not sink.
I have seen great piles of glistening salt along the shore of Great Salt Lake which had been obtained by evaporation. A railroad runs beside the lake, and the salt is loaded upon the cars to be hauled away. When the people first settled in Utah, they used to drive to the lake in wagons to get a supply of salt.
Although the ocean and a few lakes contain immense quantities of this useful article, we get most of our supply from other sources.