An American Robinson Crusoe by Daniel Defoe

Now for the food. Could Robinson preserve the meat? He had often heard his mother tell about preserving meat in salt. He had even eaten salt meat, pickled meat. But where could he get salt?

One day when the wind blew hard the water was driven upon the shore and filled a little hollow. After a few days the ground glistened white as snow where the water had been. Was it snow? Robinson took it in his hands and put it in his mouth. It was salt. The sun had evaporated the water in the hollow -- had vaporized it -- and the air had drunk it up. What was left behind? Salt. Now he could get salt as long as he needed it.