shake it well. The water becomes muddy. It looks like the water which you see running down the street when it rains. Put your hand in the basin and at the bottom you can feel something soft like mud.

Pour the muddy water out of the basin into another dish. Pour in more water and again shake the basin. Turn off the muddy water as before. After you have done this a number of times the mud will be gone.

Now the water remains quite clear.

There

Let us see what there is left of the soil. in the bottom of our basin is a thin layer of sand. It looks much like the sand by the brook or upon the beach, but the grains are not of the same size. The larger grains have sharp points.

The sand by the brook was once mixed with clay. The water as it ran along finally washed the clay away and carried it down toward the river. The grains of sand were made smooth, so that we can find no sharp points upon them.

Let us turn now to our jar of muddy water. After it has stood some hours the water no longer looks dirty. The fine particles of clay or mud which floated in the water have settled to the bottom. The clay feels very soft and slippery. There are no grains of sand in it.

Is there anything else in the water besides the clay? Yes, upon its surface there are many little

pieces of leaves and stems of plants.

and crumble if we try to pick them up.

These are soft

We have found three things in the soil. There is first the sand, which feels hard and gritty when we rub it in our fingers. Then there is the clay in which we can feel no grit. When the clay dries it crumbles to a fine powder, and looks like the dust in the road. Last of all, there are the little pieces of plants.

Some kinds of soil contain much sand and little clay. Others are formed mostly of clay.

Would you not like to know how the soil is

made?

QUESTIONS.

What is meant by poor soil and rich soil?

What is it in the soil which makes it sticky when wet?

Will plants grow in clean sand?

Do all plants like the same kind of soil?

What do you think makes the soil dark? What is the color of the plant stems which you find in the soil?

What is dust?

Pour water on some sand and also on some clay. Into which does it sink faster?

What becomes of plants when they die?

Is the soil in your garden dark colored or light?

What is sand used for?

from?

HOW THE SOIL IS MADE.

How is the soil made? Where does it come

We can learn something about the soil if we watch the men who are grading a road through the hill. Some of the men are driving horses hitched to great shovels on wheels. The horses pull the shovels over the ground and scrape off the soft dirt. This top dirt we call the soil. It is dark in color and full of grass roots and pieces of leaves and stems of plants.

Below the dark soil the men find the ground harder. Some of them are using picks to loosen it. A little deeper the ground becomes so hard that they can no longer pick it.

Then they bring long iron rods called drills, and make holes, in this hard ground. They put powder into the holes and explode it. The ground is blown into pieces which can be shoveled up and drawn away.

This hard ground is called rock. Soil is made from rock. We have already seen that where the men are working the soil forms only a thin layer on the top of the ground. As they dig deeper the soil soon disappears and rock takes its place. If you dig a hole in the ground anywhere you will at last come to rock. In some places the soil is very deep.

Here is a piece of rock which the men have blasted out. How bright and clean it is! There are sharp corners upon it which may scratch your fingers. How strange it is that rock like this can change to soil!

We will take a piece of the rock and pound it to dust. Why cannot we call this pounded rock, soil? It does not look like the dark soil which the men found on the top of the ground.

Let us plant some seeds in a pot of the dust

which we made by pounding the piece of rock. We will also plant some in a pot of the dark soil. In this way we can learn how our pounded rock differs from the soil which Nature made.

In a few days the seeds sprout, and for a time the tiny blades in one pot look just like those in the other. Then a change comes. The little plants in the pot of rock dust almost cease to grow. They lose their bright green color. The plants in the other pot keep on growing. This is because the dark soil is full of food all ready for the plant to use, while the rock dust has but little food ready for the little roots to take up.

We have discovered now that the soil is something more than rock dust. Nature makes the soil from the rock in a very different way.

rocks.

A long time ago there was no soil covering the
Do you think we could have lived upon the

earth then?

For many years the sun shone upon the rocks, and every day they became quite warm. At night when the sun was gone they grew cold. The little grains of which the rocks are made became larger when they were warm and crowded each other. When it was cold they shrank away from each other. In this way little cracks were made.

Rain fell upon the rocks and ran into the cracks