Читать книгу The House We Live In; or, The Making of the Body онлайн

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A bone tied in a knot, after the earthy matter has been removed by an acid.

In very old people the bones contain more earthy matter, and they break easily. Grand´fa-ther and grand´moth-er must be careful not to fall, for if they break a bone it will take a long time to heal.

When we take a baby, we should not lift him by his arms, and we must hold him so his bones will not grow out of shape. As he grows older, enough earthy matter will go into his bones to make them hard and strong.

Percy: But you said there was lime in the bones, mother.

Mother: Yes, the earthy matter is partly lime. The blood goes into the bones through tiny blood-vessels, and at all times of day and night the bones keep eating their breakfasts, dinners, and suppers of lime, which they find in the blood.

“We should not lift him by his arms.”

Helen: What kind of food is best for the bones?

Mother: Good whole-wheat bread will furnish them all they need. Peas and beans are also good.

Back-bone.

We will now look at the largest bones of our body frame, and see if we can learn something of their size and shape. We will not try to learn their hard names now, but will leave that till we are older.