these sympathetic eye curtains is one which may be followed while you are
out walking on the street some dark winter night. A gas lamp seen at a
distance is, comparatively speaking, a point of light, with bars of light
emanating from it in many directions. These bars, which give the peculiar
spoked appearance to a star, are probably formed by optical defects of the
lens within the eye, or by the tear fluid on the exterior surface of the
eye, or by a combination of all these causes. Be that as it may, the
lengths of the spokes of light are limited by the inner margin of the eye
curtain; if the curtain be drawn up, then the spokes are long; if the
curtain be let down, or, in other words, if the pupil be very small and
contracted, then one can not see any spokes at all. Hence, as I look at a
distant gaslight, with its radiating golden spokes, I am looking at
something which will give me a sure indication of any movements of the eye
curtains. I strike a match and allow its light to fall into the eyes; the
spokes of the distant gas lamp have retreated into the point of flame as
if by magic; as I take the burning match away from before my eyes, the
spokes of the gas-lamp venture forth again. The experiment may be utilized
to see how much light is required to move the window curtains of the eyes.
Suppose you are walking toward two gas lamps, A and B; B about fifty yards
behind A. If you steadfastly look at B and at the golden spokes apparently
issuing from it, you may make these spokes a test of how soon the light of
A will move your iris. As you gradually approach A, you come at last to a
position where its light is strong enough to make the spokes of B begin to
shorten; a little nearer still and they vanish altogether. I have found
that about a third of the light which is competent to contract the pupil
very markedly will serve to commence its movement.--WILLIAM ACKROYD.
PURKINJE'S FIGURES (p. 222).--Stand in a dark room with a lighted candle
in hand. Shutting the left, hold the candle very near the right eye,
within three or four inches, obliquely outward and forward, so that the
light shall strongly illuminate the retina. Now move the light about
gently, upward, downward, back and forth, while you gaze intently on the
wall opposite. Presently the field of view becomes dark from the intense
impression of the light, and then, as you move the light about, there
appears projected on the wall and covering its whole surface, a shadowy,
ghost-like image, like a branching, leafless tree, or like a great
bodiless spider with many branching legs. What is it? It is an exact but
enlarged image of the _blood vessels of the retina_. These come in at
the entrance of the optic nerve, ramify in the middle layer, and therefore
in the strong light cast their shadows on the bacillary layer of the
retina. The impression of these shadows is projected outward into the
field of view, and seen there as an enlarged shadowy image. These have
been called Purkinje's Figures, from the discoverer.--PROF. JOSEPH LE
CONTE, _in Sight_.
XI.
APPENDIX.
QUESTIONS FOR CLASS USE.
_The questions include the Notes and the Selected Readings. The figures
refer to the pages_.
INTRODUCTION.
Illustrate the value of physiological knowledge. Why should physiology be
studied in youth? When are our habits formed? How do habits help us? Why
should children prize the lessons of experience? How does Nature punish a
violation of her laws? Name some of Nature's laws. What is the penalty of
their violation? Name some bad habits and their punishments. Some good
habits and their rewards. How do the young ruin their health? Compare
one's constitution with a deposit in the bank. Can one in youth lay up
health as he can money for middle or old age? Is not the preservation of
one's health a moral duty? What is suicide?
THE SKELETON.
3. How many bones are there in the body? Is the number fixed? Is the
length of the different bones proportional? What is an organ? A function?
Name the three uses of the bones. Why do the bones have such different
shapes?
4. Why are certain bones hollow? Round? Illustrate. Compare the resisting
property of bone with that of solid oak. What is the composition of bone?
How does it vary? How can you remove the mineral matter? The animal
matter? Why is a burned bone white and porous? What food do dogs find in
bones?
5. What is the use of each of the constituents of a bone? What is
"boneblack"? What is ossification? Why are not the bones of children as
easily broken as those of aged persons? Why do they unite so much quicker?
What are the fontanelles?
6. Describe the structure of a bone. What is the object of the filling?
Why does the amount vary in different parts of a bone? What is the
appearance of a bone seen through a microscope?
7. What is the periosteum? Is a bone once removed ever restored? What are
the lacunæ? The Haversian canals? Why so called? _Ans_. From their
discoverer, Havers. Define a bone. [Footnote: Bone structure may be
summarized as follows: A bone is a collection of _Haversian
elements_, or rods. An Haversian element consists of a tube surrounded
by _lamellæ_, which contain _lacunæ_, connected by _canaliculi_.--DR.
T. B. STOWELL.] What occupies the lacunæ? _Ans_. The bone cells
(osteoblasts). How do bones grow?
8. Illustrate. How does a broken bone heal? How rapidly is bone produced?
Illustrate. Objects of "splints"? Describe how a joint is packed.
Lubricated.
9. How are the bones tied together? What is a tissue? Illustrate. Name the
three general divisions of the bones. What is the object of the skull?
Which bone is movable? How is the lower jaw hinged? Describe the
construction of the skull. What is a suture?
10. Tell how the peculiar form and structure of the skull adapt it for its
use. Illustrate the impenetrability of the skull.
11. Describe the experiment of the balls. What does it show? What two
cavities are in the trunk? Name its principal bones. Describe the spine.
12. What is the object of the processes? Of the pads? Why is a man shorter
at night than in the morning? Describe the perfection of the spine.
13. Describe the articulation of the skull with the spine. Why is the
atlas so called?
14. Describe the ribs. What is the natural form of the chest? Why is it
made in separate pieces? How does the oblique position of the ribs aid in
respiration? (See note, p. 80.)
15. How do the hipbones give solidity? What two sets of limbs branch from
the trunk? State their mutual resemblance. Name the bones of the shoulder.
Describe the collar bone.
16. Describe the shoulder blade. Can you describe the indirect
articulation of the shoulder blade with the trunk? Name the bones of the
arm. Describe the shoulder joint. The elbow-joint.
17. Describe the wrist. Name the bones of the hand. How many bones in the
fingers? The thumb? What gives the thumb its freedom of motion?
18, 19. Name and describe the fingers. In what lies the perfection of the
hand? How do the gestures of the hand enforce our ideas and feelings?
Describe the hip joint. What gives the upper limbs more freedom of motion
than the lower? How does the pressure of the air aid us in walking?
Illustrate.
20. Name the bones of the lower limbs. Describe the knee joint. The
patella. What is the use of the fibula? Can you show how the lower
extremity of the fibula, below its juncture with the tibia, is prolonged
to form a part of the ankle joint? Name the bones of the foot. What is the
use of the arch of the foot? What makes the step elastic? Describe the
action of the foot as we step.
21. In graceful walking, should the toes or the heel touch the ground
first? What are the causes of deformed feet? What is the natural position
of the big toe? Did you ever see a big toe lying in a straight line with
the foot, as shown in statuary and paintings? How should we have our boots
and shoes made? What are the effects of high heels? Of narrow heels? Of
narrow toes? Of tight-laced boots? Of thin soles? What are the rickets?
Cause of this disease? Cure? Is there any provision for remedying defects
in the body? Name one.
22, 23. What is a felon? Cure? Cause of bowlegs? How can they be
prevented? Causes of spinal curvature? Cure? What is the correct position
in sitting at one's desk? Is there any necessity for walking and sitting
erect? Any advantage aside from health? Describe the bad effects of a
stooping position. What is a sprain? Why does it need special care? What
is a dislocation? How is it generally caused? How soon should it be
treated?
269. What relation does man, in his general structure, bear to other
vertebrates? Mention some marked physical peculiarities which distinguish
him from the lower mammals.
270, 271. Describe the state of a fracture a week after its occurrence.
What is this new formation called? What marks the termination of the first
stage of curative progress? How do the broken ends of the bone now appear?
What is the state of the fracture at the end of the second stage? What is
the condition of the callus at this time? Describe the third and last
series of changes. Is the process of union completed sooner in old people
or in young? In the upper or lower extremities? In smaller animals or man?
What length of time is required to heal a broken arm? A broken leg?
272. What gives the human hand its peculiar prehensile power? What
advantage has the human thumb over that of the ape? Compare the foot of
man with that of the ape. What peculiarity of the foot is particularly
noticeable in man? Contrast the function of the great toe in man and in
the ape.
273. Are the toes naturally flexible? How are their powers crippled? Give
an instance in which the toes were trained to do the work of the fingers.
274. Why are an elastic step and a graceful carriage such rare
accomplishments? What is the natural shape of the foot? Which is the
longer, the great toe or the second toe? Is an even-sided symmetry
necessary to the beauty of a boot?
THE MUSCLES. 29. What relations do the skeleton and the muscles bear to
each other? How is the skeleton concealed? Why is it the image of death?
What are the muscles? How many are there? What peculiar property have
they? Name other properties of muscles. _Ans_. Tonicity, elasticity.
30. How are they arranged? Where is the biceps? The triceps? How do the
muscles move the limbs? Illustrate. What is the cause of squinting? Cure?
(See p. 244.)
31. Name and define the two kinds of muscles. Illustrate each. What is the
structure of a muscle? Of what is a fibril itself composed? How does the
peculiar construction of the muscle confer strength?
32. Describe the tendons. What is their use? Illustrate the advantages of
this mode of attachment.
33. What two special arrangements of the tendons in the hand? Their use?
How is the rotary motion of the eye obtained?
34, 35. What is a lever? Describe the three classes of levers. Illustrate
each. Describe the head as a lever. What parts of the body illustrate the
three kinds of levers? Give an illustration of the second class of levers.
The third class. Why is the Tendon of Achilles so named? What is the
advantage of the third class of levers? Why desirable in the hand? What
class of lever is the lower jaw?
36. What advantages are gained by the enlargement of the bones at the
joints? Illustrate. How do we stand erect? Is it an involuntary act?
37. Why can not a child walk at once, as many young animals do? Why can we
not hold up the head easily when we walk on "all fours"? Why can not an
animal stand erect as man does?
38. Describe the process of walking. Show that walking is a process of
falling. Describe the process of running. What causes the swinging of the
hand in walking? Why are we shorter when walking? [Footnote: Stand a boy
erect against a wall. Mark his height with a stick. Now have him step off
a part of a pace, and then several whole paces. Next, let him close his
eyes, and walk to the wall again. He will be perceptibly lower than the
stick, until he straightens up once more from a walking position.] Why
does a person when lost often go in a circle? In which direction does one
always turn in that case? [Footnote: Take several boys into a smooth grass
lot. Set up a stick at a distance for them to walk toward. Test the boys,
to find which are left-handed, or right-handed; which left-legged or
right-legged. Then blindfold the boys and let them walk, as they think,
toward the mark. See who varies toward the right, and who turns to the
left.]
39. What is the muscular sense? Value of educating it? How do we gratify
it?
40. What effect has exercise upon a muscle? Is there any danger in violent
exercise? For what purpose should we exercise? Should exercise be in the
open air? What is the rule for exercise? Is a young person excusable, who
leads a sedentary life, and yet takes no daily outdoor exercise? What will
be Nature's penalty for such a violation of her law? Will a postponement
of the penalty show that we have escaped it?
41. Ought a scholar to study during the time of recess? Will a promenade
in the vitiated air of the schoolroom furnish suitable exercise? What is
the best time for taking exercise? What class of persons can safely
exercise before breakfast?
42. What are the advantages of the different kinds of exercise? Should we
not walk more? What is the general influence upon the body of vigorous
exercise?
43. State some of the wonders of the muscles. What is the St. Vitus's
Dance? Cure?
44. What are convulsions? What is the locked-jaw? Causes? The gout? Cause?
Cure? The rheumatism? Its two forms? Peculiarity of the acute?
45. Danger in acute rheumatism? In what does chronic rheumatism often
result? What is lumbago? Give instances. What is a ganglion? Its cure? A
bursa?
275. What is meant by the origin of a muscle? The attachment? Is a muscle
always extended between two contiguous bones? Give an illustration. Can
the points of origin and of attachment change offices? Illustrate. What is
an important consequence of the attachment of the muscles to the bones?
If, in the limb of a dead body, one end of a muscle is separated from its
point of attachment, what occurs? Would the result be the same during
life? To what is this phenomenon due?
276. Why are the muscles continually striving to shorten? Describe the
effect when several opposing muscles are attached to one bone. When is the
balanced position of the limbs best observed? Are the muscles always
attached to bones? Give example. How does the flesh of man differ from
that of an ox? How may the structure of muscular fibers be rudely
illustrated? Describe smooth muscle fibers. How do they differ from
striated muscle fibers?
277. In what form do smooth muscle fibers frequently occur? In such cases,
how are they usually arranged? What is the effect of their contraction? Of
what especial use is this power in case of the smaller arteries? In case
of the intestine?
278. In the latter instance, how does the contraction take place? Are the
striated muscle fibers voluntary or involuntary? Name an exception to this
rule. Give other peculiarities of the muscle fibers of the heart. What
causes the contraction of smooth muscle fibers? Of striated muscle fibers?
Why do little children seldom injure themselves by overexertion? How is
the danger increased in youth?
279. What class of people are in most peril from violent or excessive
exercise? Why? At what age should one cease from haste of all kinds? Give
instances of valuable lives lost from personal imprudence.
280. What are the effects of insufficient exercise upon the young? How
does it predispose to disease? What makes the children of the laboring
classes so hardy? Is a regulation step desirable in walking? Why not? Why
is it more fatiguing to walk uphill than on level ground?
281. How does the management of the breath affect this fatigue? How should
a belt be worn, if used during exercise? Can other forms of exercise be
successfully substituted for walking? Why not? What is the difference in
movement between walking and skating? Which is the better exercise? What
are the dangers from skating? What precaution should be used by those who
have weak ankles?
282. Name the different action of the muscles in the forward and backward
movements in rowing. What is the comparative value of rowing as an
exercise? Why is it especially desirable for women? How should women dress
when rowing, horseback riding, tennis playing, etc.? What rules should be
observed by rowers? Why should the breath be allowed to escape while the
oar is in the water?
283. What sanitary measures should be observed after a row? What effect
has too frequent and too prolonged immersion on young swimmers? Does
swimming require much muscular exertion? Why? Why does an occasional
swimmer become exhausted sooner than an experienced one? On what do ease
and speed in swimming depend? Is the habit of diving desirable? Should
diving ever be practiced in shallow water?
284. Why is lawn tennis the most desirable of outdoor games? _Ans_.
Not only because nearly every muscle of the body is brought into exercise,
but because it is one of the few field sports in which women can
gracefully join. In this it shares the honor with croquet. What are the
dangers attendant on lawn tennis? From what do many of them arise? Why
should tennis shoes have heels? To what class of people is horseback
riding particularly suited? What class of invalids should not indulge in
bicycling and tricycling? To what class is it peculiarly beneficial?
285. What are the dangers attendant on baseball games? Football? When may
light and heavy gymnastics be profitably employed? Name a sufficient
apparatus. What are the objections to gymnasium exercise? Its advantages?
THE SKIN.
49. What are the uses of the skin? Describe its adaptation to its place.
What is its function as an organ? Describe the structure of the skin. The
sensitiveness of the cutis. The insensitiveness of the cuticle.
50. How is the skin constantly changing? The shape and number of the
cells? Value of the cuticle? How is the cuticle formed? _Ans_. By
secretion from the cutis.
51. What is the complexion? Its cause? Why is a scar white? What is the
cause of "tanning"? What are freckles? Albinos? Describe the action of the
sun on the skin.
52. Why are the hairs and the nails spoken of under the title of the skin?
Uses of the hair? Its structure? How can it be examined? What is the hair
bulb? What is it called? How does a hair grow? At what rate? When can it
be restored, if destroyed? Does hair grow after death?
53. When hair has become gray, can its original color be naturally
restored? What is the danger of hair dyes? Are they of any real value? How
can the hair stand on end? How do horses move their skin? Is there any
feeling in a hair?
54. Illustrate the indestructibility of the hair. What are the uses of the
nails? How do the nails grow? What is the mucous membrane?
55. Its composition? The connective tissue? Why so called? What uses does
it subserve?
56. What is its character? How does the fat exist in the body? Its uses?
State the various uses of membrane in the body. Where is there no fat?
Where is there always fat?
57. Why are the teeth spoken of in connection with the mucous membrane?
Name and describe the four kinds of teeth. What are the milk teeth?
Describe them. What teeth appear first?
58. Give the order and age at which they appear. When do the permanent
teeth appear? Describe their growth. Which one comes first? Last?
59. Describe the structure of the teeth. How are the teeth fitted in the
jaw?
60. Why do the teeth decay? What care should be taken of the teeth? What
caution should be observed? What are the oil glands?
61. Use of this secretion? What are the perspiratory glands? State their
number. Their total length. What are the "pores" of the skin?
62, 63. What is the perspiration? What is the constitution of the
perspiration? Illustrate its value. Name the three uses of the skin.
Illustrate the absorbing power of the skin. What precaution should be
observed in handling a dead body? Why are cosmetics and hair dyes
injurious? What relation exists between the skin and the lungs? What
lesson does this teach? When is the best time for a bath? Why?
64, 65. What is the value of friction? Why should not a bath be taken just
before or after a meal? Is an excess of soap beneficial? What is the
"reaction"? Explain its invigorating influence. How is it secured? General
effect of a cold bath? Of a warm bath? If we feel chilly and depressed
after a bath, what is the teaching? Describe the Russian vapor bath. Why
is the sea bath so stimulating?
66. How long should one remain in any bath? How does clothing keep us
warm? Explain the use of linen as an article of clothing. Cotton. Wool.
Flannel. How can we best protect ourselves against the changes of our
climate?
67. What colored clothing is best adapted for all seasons? Value of the
nap? Furs? Thick _vs_. thin clothing? Should we wear thick clothing
during the day, and in the evening put on thin clothing? Can children
endure exposure better than grown persons? What is the erysipelas? How
relieved?
68, 69. Eczema? What do its various forms denote? Corns? Cause? Cure?
Ingrowing nails? Cure? Warts? Cure? Chilblain? Cause? Preventive?
286. Name some causes of baldness. Give Dr. Nichols's opinion. Why is
frequent shampooing inadvisable? One probable reason why women are less
frequently bald than men? What is the best general treatment for the hair
and scalp? Upon what does the color of the hair mainly depend?
287. In cases of sudden blanching of the hair what is the effect upon the
pigment? Give an illustration. How do the extra air bubbles find their way
into the hair? Does air naturally exist in the hair? What relation do the
nails bear to the scarfskin?
288. What causes the horny appearance of the nails? Describe the root of
the nail in its relation to the sensitive and the scarfskin. Upon what
does the nail rest? What is its appearance? What is the lunula? Why is it
lighter than the rest of the nail? How does the nail increase in length?
In thickness? Where is the greatest thickness? How does the growth of the
nail during disease compare with its growth in health?
289. How long does it take the thumb nail to grow from its root to its
free extremity? The great toe? Give general rules for the care of the
nails. How does physical cleanliness promote moral purity? What does its
neglect indicate?
290. What especial care should be taken in regard to the feet? Why? Are
baths a modern refinement? What can you say about the ancient Greek and
Roman baths? What constitutes the value of the Turkish bath?
291. What class of people should never use this bath? To what class of
invalids is it particularly beneficial? Is sea bathing advisable for
persons of all ages? How should an inexperienced sea bather begin? When
should the sea bath be taken?
292. How long should a delicate person remain in the water? State the
danger of bathing when overheated. Under what conditions of body and of
temperature should sea or river bathing be avoided? Why? Give illustration
of the English soldier. How should the temperature of the water, in
bathing, compare with that of the air? Of the body?
293. Describe the bathers' cramp. What are its causes? What precaution
should be used by bathers in regard to the mouth and ears? Why?
294. How can a person who does not know how to swim, save himself from
drowning?
295. What are the advantages of woolen clothing? Why is it particularly
desirable in malarial countries? What double purpose does woolen clothing
serve in semitropical climates?
296. Does the warmth of clothing depend on its weight? What errors are
often made and with what effect? State what is said in regard to poisonous
dyes in wearing apparel. Give illustration.
297. What effect has uncleanly attire on the health? Does this apply to
outer as well as under garments?
RESPIRATION AND THE VOICE.
73. Name the organs of respiration and the voice. Describe the larynx. The
epiglottis. The sophagus. What is meant by food "going the wrong way"?
74. Describe the vocal cords. Their use. How is sound produced?
75. How are the higher tones of the voice produced? The lower? Upon what
does loudness depend? A falsetto voice? What is the cause of the voice
"changing"? What is speech? Is the tongue necessary to speech? Illustrate.
(See also page 298.)
76. What is vocalization? How are talking machines made?
77. How is _a_ formed by the voice? What is _h_? Difference
between a sigh and a groan? What vowel sounds are made in laughing? Does
whistling depend on the voice? Tell how the various consonants are formed.
What are the labials? The dentals? The linguals? What vowels does a child
pronounce first?
78. Describe the windpipe. The bronchi. The bronchial tubes. Why is the
trachea so called? Describe the structure of the lungs. What are the lungs
of slaughtered animals called? Why will a piece of the lungs float on
water?
79. Name the wrappings of the lungs. Describe the pleura. How is friction
prevented? What are the cilia? Their use?
80. What two acts constitute respiration? In what two ways may the
position of the ribs change the capacity of the chest? Describe the
process of inspiration. Describe the diaphragm.
81. What is the process of expiration? How often do we breathe? What is
sighing? Coughing? Sneezing? Snoring? Laughing? Crying?
82. Describe hiccough. Yawning. Its value? What is meant by the breathing
capacity? How does it vary? How much, in addition, can the lungs expel
forcibly? How much of the breathing capacity is available only through
practice? Value of this extra supply? Can we expel all the air from our
lungs? Value of this constant supply?
83. How constant is the need of air? What is the vital element of the air?
Describe the action of the oxygen in our lungs. What does the blood give
up? Gain? What are the constituents of the air? What are the peculiar
properties and uses of each?
84. How can we test the air we exhale? What does its analysis reveal?
Which is the most dangerous constituent? What occurs when we rebreathe
exhaled air?