3. The Nose.--My nose is to smell and breathe with; it is in the middle of my face:
my two nostrils,
the bridge of my nose, the cartilage,
the tip of my nose.
My nostrils lead to a passage back of my mouth through which I breathe. The cartilage separates my nose into two parts.
4. The Mouth.--My mouth is to speak, eat, and breathe through:
my upper lip, my lower lip. [21]
In my mouth are:
my tongue,
my lower teeth, my upper teeth, my lower teeth,
and my upper and lower jaws, covered with flesh called gum.
5. The Teeth.--My teeth are used in eating and talking.
My teeth are made of a soft kind of bone, covered with enamel.
I have three kinds of teeth: cutting teeth, tearing teeth, grinding teeth. A young child has twenty teeth, ten in each jaw.
A grown person has thirty-two teeth, sixteen in each jaw.
6. To preserve my teeth: I must keep them clean.
I must not scratch the enamel.
I must not eat or drink anything very hot or very cold. I must not use them for scissors or nut-crackers.
I must not burn them with tobacco or cigars.
7. About Eating.--When I eat I move my lower jaw only.
My tongue brings the food between my teeth, the cutters cut it,
the tearers tear it,
the grinders grind it, the saliva moistens it,
and my tongue helps me to swallow it.
QUESTIONS FOR THE FORMULAS.
1. Tell about your eyes.
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2. Tell about your ears.
3. Tell about your nose.
4. Tell about your mouth.
5. Tell about your teeth.
6. What is necessary if you would preserve your teeth?
7. Tell about eating. [22]
1, the muscle which raises the upper eyelid.
2, the upper oblique muscle.
7, the lower oblique muscle. The oblique muscles roll the eye inward and downward.
4, 5, 6, three of the four straight muscles. Two of the straight muscles roll the eye up and down; the other two move it right and left.
3, the pulley through which the upper oblique muscle plays.]
QUESTIONS ON THE DESCRIPTION OF THE EYES. Of what shape is the eye?--"It is round like a ball."
In what is it placed?--"In a deep, bony socket." What is a socket?--"A hollow place."
Why is the eye placed in a deep, bony socket?--"To keep it from getting hurt."
Why would not an eye shaped like a cube do for us?--"It would not look well; it could not be rolled about." Why would not an eye shaped like a cone or cylinder do for us?--"It could not be rolled in every direction." Why is the ball-shape best for the eye?--"It looks best, and may be rolled in every direction."
What part of the eye do we see through?--"The black spot in the centre." What is it called?--"The pupil."
[23]
What shape is the pupil?--"Round like a circle." What color is the pupil?--"Black."
Of what use is the pupil?--"To let light into the eye; to see through."
What is around the pupil?--"A colored ring."
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What is the colored ring called?--"The iris."
Of what use is the iris?--"It acts like a curtain to the eye; it lets in and keeps out light from the pupil."
Of what shape is the iris?--"Round like a ring."
Of what color is the iris?--"Sometimes blue, sometimes brown, sometimes gray."
Does the iris always appear the same in size?--"It does not: sometimes it looks large, sometimes small." When is it the largest?--"When it rolls over the pupil to keep out the strong light."
When is it the smallest?--"When it rolls backward, to let light into the pupil." When is the pupil the largest?--"When we are in the dark."
When is the pupil the smallest?--"When we are in a bright light." What color is the eyeball?--"White."
What shape is the eyeball?--"Round like a ball."
How is the eyeball held in its socket?--"By cords made of flesh."
Where are the eyebrows?--"Above the eyelids."
Of what use are the eyebrows?--"To keep the perspiration from rolling into the eyes." Where are the eyelids?--"Over the eyes."
Of what use are they?--"They cover the eyes and keep them from getting hurt." Where are the eyelashes?--"On the edges of the eyelids."
Of what use are the tears?--"They keep the eyes clean; they make the eyes move easily in their sockets."
Where are the tears made?--"Back of the eyebrows."
When do the tears wash the eyes?--"Every time we wink our eyelids."
[24]
QUESTIONS ON THE EARS. Name the parts of the ear.
Where are your ears?--"On the sides of my head." Which is the rim of the ear?--"The edge of the ear." Which is the flap of the ear?--"The lower part of the ear." Where is the drum of the ear?--"Inside of the ear."
How is the drum protected?--"By stiff hairs and a bitter wax at its entrance."
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QUESTIONS ON THE NOSE.
Where is the nose?--"In the middle of the face." Name the parts of the nose.
Where is the tip of the nose?--"At the end of the nose."
Where is the bridge of the nose?--"At the top of the nose, between the eyes." Where is the cartilage?--"In the middle of the inside of the nose."
Of what use is the nose?--"To smell and breathe through." What are the nostrils?--"The openings inside of the nose."
Of what use are the nostrils?--"To let the air into and out of the opening back of the mouth."
QUESTIONS ON THE MOUTH, ETC.
Where is the mouth?--"In the lower part of the face, between the nose and the chin." Of what use is the mouth?--"To breathe, speak, and eat through."
What is in the mouth?--"My tongue, my upper teeth, my lower teeth, and my upper and lower jaws."
What covers the jaws?--"Red flesh, called gum."
Of what are the jaws composed?--"Of bones."
Of what are the teeth made?--"Of dentine, covered with enamel." See note, p. 19. [25]
What is enamel?--"A smooth, white substance, harder than bone." Of what use are the teeth?--"To eat and talk with."
What kinds of teeth have you?--"Cutting teeth, tearing teeth, grinding teeth." Describe the cutting teeth.--"The cutting teeth have broad and flat edges." Describe the tearing teeth.--"The tearing teeth are sharp and pointed." Describe the grinding teeth.--"The grinding teeth are the thick, back teeth." Which jaw is moved in eating?--"The lower jaw."
What work do the teeth perform?--"They cut, tear, and grind the food." How many teeth has a child in a full set?--"Twenty teeth: ten in each jaw."
How many teeth has a grown person in a full set?--"Thirty-two: sixteen in each jaw."
What does the tongue do in eating?--"It rolls the food between the teeth, and helps in swallowing."