Rock-salt is dug out of the earth. It looks like a piece of smooth, shiny stone. Water is always soaking through the earth. Some of this water, as it soaks through, dissolves the rock-salt, and makes brine, and then we get a brine-spring. Men pump up this brine and boil it. The water boils away, and leaves the salt behind. This is the white salt we see on the dinner table.
Lesson 25
A Plant
"I wonder," said Fred, "whether Norah could tell the name for those things, which we dig out of the ground.""Oh, you mean minerals," replied Norah, "like chalk, and clay, and salt, and stone.""Quite right," said Fred. "But teacher showed us some things that are not minerals, although weget them out of the ground. Think of all the pretty flowers in the beds, the carrots, turnips, beans, and potatoes in the garden, the green grass, and the great tall trees.
"We get them all out of the ground, but they are not minerals. They live and grow in the ground. We call them plants. We know they live, because if we treat them badly we can see them die. Minerals lie in the ground, but they are not living things, and they do not grow. Plants are living, growing things.