What is the saliva?--"A kind of liquid, sometimes called spit." Of what use is it in eating?--"It wets and softens the food." What do you mean by preserve?--"To keep from injury." What do you mean by injury?--"Hurt."
How do you preserve your teeth? See Formula.
How do very hot or very cold drinks hurt the teeth?--"They crack the enamel." What happens if the enamel is cracked?--"The teeth decay."
Then what must you do to preserve your teeth?--"I must try to keep the enamel from being cracked or injured in any way."
[26] PART V.
FORMULA FOR DESCRIPTION OF THE BONES.
1. My skull is formed of several bones united, like two saws with their toothed edges hooked into each other.
2. My spine extends from the base of the skull behind, down the middle of my back.
It is composed of twenty-four short bones, piled one upon the other, with cartilage between them.
These bones are fastened together, forming an upright and flexible column, which makes me erect and graceful.
3. My ribs are curved, strong, and light; there are twenty-four of them, twelve on each side; they are fastened at the back to my spine,
in front to my breastbone, forming a hollow place for my heart, lungs, and stomach.
4. My shoulder blades are flat, thin, and like a triangle in shape; they are for my arms to rest upon.
5. My collar bones are fastened to my shoulder blades and my breastbone; they keep my arms from sliding too far forward.
6. The bones of old people are hard and brittle; those of children soft and flexible; so I must sit and stand erect, that mine may not
be bent out of shape. I must not wear tight clothing, or do anything that will crowd them out of their places.
7. My bones are made from my food, after it has been changed into blood; so I must be careful to eat good, wholesome food, that
they may be strong and healthy. [27]
8. I must not breathe impure air, because impure air makes bad blood, and bad blood makes poor bones.
9. The body of every person is changing all the time, because the skin, flesh, and bones are always wearing out, and the blood is
always repairing and building them again.
QUESTIONS FOR THE FORMULA.
1. Tell about the skull.
2. Tell about the spine.
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3. Tell about the ribs.
4. Tell about the shoulder blades.
5. Tell about the collar bones.
6. Tell about the difference between the bones of old people and those of children.
7. Of what are your bones made?
8. If you wish your bones to be strong, why should you not breathe impure air?
9. What have you learned about the change which is always taking place in the body?
THE JOINTS OF THE SKULL. [28]
A little girl was looking at some pictures of ladies in fashionable dresses. While admiring the beautiful styles and bright colors of the garments, she pointed to the waist of one, and exclaimed, "That means trouble." The waist was too small for a grown person, and could only have been made so by tight-lacing. The child had been taught that dresses, corsets, coats, vests, bands, or anything fastened tightly around the waist, press upon the ribs and crowd them out of place, preventing the heart, lungs, and other inside organs from working as they should, causing headache, dyspepsia, shortness of breath, and often ending in some incurable disease, so she knew that tight clothing means trouble to the wearer.
FIG. 2. A natural, well-shaped chest. FIG. 1. Deformed by tight-lacing. QUESTIONS ON THE DESCRIPTION OF THE BONES.
Point to the skull.
Of what is it made?--"Several bones united together."
How are the skull bones united?--"Like two saws with their toothed edges hooked into each other." What do you mean by toothed?--"Having points, like teeth."
What covers the skull?--"Flesh, skin, and hair." Of what use is the skull?--"It protects the brain."
What is the brain?--"That part of my body in which the thinking is done." [29]
Where is the spine?--"It extends from the base of my skull behind, down the middle of my back." What do you mean by extends?--"Goes from."
What do you mean by base?--"The lower part of anything."
Of what is the spine made?--"Of about twenty-four short bones, with cartilage between them."
What is cartilage?--"An elastic substance, harder than flesh, but softer than bone."
How are the bones of the spine placed?--"They are piled one upon the other."
What do you mean by forming?--"Making."
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What do you mean by upright?--"In a vertical position."
What do you mean by flexible?--"Easily bent."
What do you mean by column?--"A pillar."
What do you mean by erect?--"In a vertical position."
Why is cartilage placed between the bones of the spine?--"To make the spine flexible; to keep the brain from injury when we walk
or run."
What do you mean by elastic?--"Springing back after having been stretched, squeezed, twisted, or bent." Tell about your ribs.--"My ribs are curved, strong, and light."
Where are your ribs?--"On each side of my trunk."
How many ribs have you?--"Twenty-four; twelve on each side."
How are your ribs fastened?--"At the back to my spine; in front to my breastbone." What do your ribs form?--"A hollow place for my heart, lungs, and stomach." Where are your shoulder blades?--"In the upper part of my back."
What shape are they?--"Flat, thin, and like a triangle."
Of what use are your shoulder blades?--"For my arms to rest upon." Point to your collar bones.
Where are they fastened?--"To my shoulder blades and my breastbone." [30]
Of what use are your collar bones?--"They keep my arms from sliding too far forward." Of what are your bones made?--"Of food after it has been changed into blood."
Why should you eat wholesome food?--"That my bones may be strong and healthy."
How does impure air hurt the bones?--"Impure air makes bad blood, and bad blood makes poor bones."
Why should you sit and stand erect?--"Because my bones are easily bent out of shape; if I do not sit and stand erect, they will grow
crooked."
Why is it wrong to wear tight clothing?--"Because tight clothing crowds the bones out of shape."
Whose bones are the more brittle, those of a child, or those of an old person?--"Those of an old person." What do you mean by brittle?--"Easily broken."
Whose are the more flexible?--"Those of a child." What do you mean by flexible?--"Easily bent."
What repairs the worn out bones, flesh, and skin of the body?--"The blood."
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What do you mean by repairs?--"Mends."
What causes the bones, flesh, and skin of your body to change often?--"The bones, flesh, and skin are always wearing out, and the
blood is always building and repairing them again."
What are alcoholic liquors?--"Liquors which have alcohol in them." Name some alcoholic liquors.--"Beer, wine, rum, etc."
Whose bones mend the more easily when broken, the bones of those who drink alcoholic liquors, or those of