[Sidenote: 6. Contraction of the muscles? Bending of the arm or finger?

Other agencies? Automatic movements? In cold-blooded animals?]

6. MUSCULAR CONTRACTION.--The muscles, when acted upon by the appropriate stimulus, contract, or so change {28} their shape, that their extremities are brought nearer together. The bending of the arm, or of a finger, is effected in this manner, by the will; but the will is not the only means of producing this effect. Electricity, a sharp blow over a muscle, and other stimuli, also cause it. Contraction does not always cease with life. In man, after death from cholera, automatic movements of hands and feet have been observed, lasting not less than an hour. In certain cold-blooded animals, as the turtle, contraction has been known to take place for several days after the head has been cut off.

[Sidenote: 7. Contractility? Give the ill.u.s.tration. What was supposed? What is the case?]

7. The property which, in muscle, enables these movements to take place is called _contractility_. If we grasp a muscle while in exercise (for example, the large muscle in the front of the arm), we notice the alternate swelling and decrease of the muscle, as we move the forearm to and fro. It was at one time supposed that the muscle actually increased in volume during contraction. This, however, is not the case; for the muscle, while gaining in thickness, loses in length in the same proportion; and thus, the volume remains the same in action and at rest.

[Sidenote: 8. What further in relation to contraction? Weariness of a muscle? Beating of the heart? Standing and walking?]

8. Contraction is not the permanent, or normal, state of a muscle. It cannot long remain contracted, but after a shorter or longer time, it wearies and is obliged to relax. After a short rest, it can then again contract. It is for this reason that the heart can beat all through life, night and day, by having, as we shall hereafter see, a brief interval of rest between successive pulsations. For the same reason, it is more fatiguing to stand for any great length of time in one position, than to be walking the same period.

[Sidenote: 9. Muscular power of animals? How tested? Man's power? Horse's?

The comparison?]

9. RELATIVE STRENGTH OF ANIMALS.--The amount of muscular power which different animals can exert, has {29} been tested by experiment. By determining the number of pounds which an animal can drag upon a level surface, and afterward comparing that with its own weight, we can judge of its muscular force. It is found that man is able to drag a little less than his own weight. A draught-horse can exert a force equal to about two-thirds of his weight. The horse, therefore, though vastly heavier than man, is relatively not so powerful.

[Sidenote: 10. Power of insects? Beetles? Give the conclusion.]

10. Insects are remarkable for their power of carrying objects larger and heavier than themselves. Many of them can drag ten, and even twenty times their weight. Some of the beetles have been known to move bodies more than forty times their own weight. So far, therefore, from it being a fact that animals have strength in proportion to their weight and bulk, the reverse of that statement seems to be the law.

[Sidenote: 11. Difference in strength of individuals? How caused?]

11. PHYSICAL STRENGTH.--The difference in strength, as seen in different individuals, is not due to any original difference in their muscles. Nature gives essentially the same kind and amount of muscles to each person, and the power of one, or the weakness of another, arises, in great part, from the manner in which these organs are used or disused.

[Sidenote: 12. Complaint in relation to degeneracy? How true? How determined by armor? The fair supposition?]

12. Many authors complain of the physical degeneracy of men at the present day, as compared with past generations. There is room for doubt as to the correctness of this statement. Certain experiments have recently been made with the metallic armor worn seven hundred years ago, by which it is found that any man, of ordinary height and muscular development, can carry the armor and wield the weapons of an age supposed to be greatly our superior in strength. When we consider that in those days, only very strong men could endure the hardships of soldier-life, {30} it is fair to suppose that our age has not so greatly degenerated in respect to physical strength.

[Sidenote: 13 Action? Use of organs? Training of the mind? The child's brain? Education of the body?]

13. IMPORTANCE OF EXERCISE.--Action is the law of the living body. Every organ demands use to preserve it in full vigor, and to obtain from it its best services. The value of that training of the mind, which we call education, is everywhere recognized. The child is early put to school, and for many years continues to study, in order that his brain, which is the great centre of mental power, may act healthfully and with force. It is important that the body, also, should receive its education by exercise.

This is especially true of persons belonging to certain cla.s.ses of society, whose occupation confines them within doors, and requires chiefly brain-work.

[Sidenote: 14 Work in the open air? A perfect business? The consequence of universal perfect business? Occupation of children?]

14. Persons who are engaged in manual labor in the open air obtain all the exercise necessary for bodily health in their regular business: their need is more likely to be a discipline or exercise of the mind. A perfect business of life, therefore, would be one which would combine both physical and mental labor in their proper proportions. If such a business were possible for all the human race, life would thereby be vastly prolonged.

Such is, in fact, to a large extent, the occupation pertaining to one period of life--childhood. A part of the time is spent by the child in improving his mind by study, and another part of the time he has physical exercise in his games and sports.

[Sidenote: 15 In what does exercise consist? Effects of it?]

15. THE EFFECTS OF EXERCISE.--Exercise consists in a well-regulated use of the voluntary muscular system. The effects, however, are not limited to the parts used. Other organs, which are not under the control of the will, are indirectly influenced by it. For instance, the heart beats more rapidly, the skin acts more freely, and {31} becomes hotter, as well as the parts beneath it, and the appet.i.te and power of digestion are increased. An increased exhalation from the lungs and skin purifies the current of the circulation, and the body as a whole thrives under its influence.

[Sidenote: 16. General effect upon the muscles? Special effect? Effects of inaction? Of excessive exercise?]

16. The immediate effect of exercise, however, is upon the muscles themselves; for by use they become firm and large, and increase in power.

If we examine a muscle thus improved by exercise, we find that its fibres have become larger and more closely blended together, that its color is of a darker red, and that the supply of blood-vessels has increased. Without exercise the muscle appears thin, flabby, and pale. On the other hand, excessive exercise, without sufficient relaxation, produces in the muscle a condition not very different from that which follows disuse. The muscle is worn out faster than nature builds it up, and it becomes flabby, pale, and weak.

[Sidenote: 17. Of violent and spasmodic efforts? Strength, how attained?

Give the particulars.]

17. Violent exercise is not beneficial; and spasmodic efforts to increase the muscular strength are not calculated to secure such a result. Strength is the result of a gradual growth, and is most surely acquired if the exercise be carried to a point short of fatigue, and after an adequate interval of rest. To gain the most beneficial results, the exercise should be at regular hours, and during a regular period. The activity of the exercise, and the time devoted to it must vary, of course, with the strength of the individual, and should be carefully measured by it.

[Sidenote: 18. What may walking be called? What further is said of walking?]

18. DIFFERENT MODES OF EXERCISE.--There are very few who have not the power to walk. There is required for it no expensive apparatus, nor does it demand a period of preliminary training. _Walking may be called the universal exercise._ With certain foreign nations, the English {32} especially, it is a very popular exercise, and is practised habitually by almost every cla.s.s of society; by the wealthy as well as by those who have no carriages; by women as well as by men.

[Sidenote: 19. What is said of running, and other like movements? What, as related to childhood? What instances are alluded to? Example?]

19. Running, leaping, and certain other more rapid and violent movements, are the forms of exercise that are most enjoyed in childhood. For the child, they are not too severe, but they may be so prolonged as to become injurious. Instances have been recorded where sudden death has resulted after violent playing, from overtaxing the heart: for example, we have the case of a young girl who, while skipping the rope, and endeavoring to excel her playmates by jumping the greatest number of times, fell dead from rupture of the heart.

[Sidenote: 20. Carriage-riding? Horseback-riding?]

20. Carriage-riding, as a means of pa.s.sive exercise, is particularly well suited to invalids, and persons advanced in life. Horseback exercise brings into use a greater number of muscles than any other one exercise, and with it there is an exhilaration of feeling which refreshes the mind at the same time. It is one of the manliest of exercises, but not less suitable for women than for men. To be skilful in riding, it is best to begin its practice in youth; but there are very few kinds of exercise of which the same is not equally true.

[Sidenote: 21. Boating, swimming, and skating?]

21. For those who live near streams or bodies of water, there are the delightful recreations of boating, swimming, and skating. Certain of these exercises have a practical importance aside from and above their use in increasing the physical vigor. This is especially true of boating and swimming, since they are often the means of saving life. Practice in these exercises also teaches self-reliance, courage, and presence of mind.

Persons who have become proficient in these vigorous exercises are generally the ones, {33} who, in times of danger, are the quickest to act and the most certain to do so with judgment.

[Sidenote: 22. What kind of exercise yields the best results? What advice is given?]

22. PHYSICAL CULTURE.--That form of exercise which interests and excites the mind, will yield the best results; but to some persons no kind of exertion whatever is, at first, agreeable. They should, nevertheless, make a trial of some exercise, in the expectation that, as they become proficient in it, it will become more pleasant. In exercise, as many sets of muscles should be employed as possible, open-air exercise being the best. Parlor gymnastics, and the discipline of the gymnasium are desirable, but they should not be the sole reliance for physical culture. No in-door exercise, however excellent in itself, can fill the place of hearty and vigorous activity in the open air.

[Sidenote: 23. Physical culture among the ancients? In Greece? In schools and colleges at the present time? Result to the body and mind?]

23. GYMNASTIC EXERCISES FOR SCHOOLS AND COLLEGES.--In the system of education among the ancients, physical culture predominated. In ancient Greece, physical exercises in schools were prescribed and regulated by law, and hence these schools were called _gymnasia_. At the present time, on the contrary, this culture is almost wholly unknown, as a part of the course of education, in our schools and colleges. In a few of our inst.i.tutions of learning, however, physical exercises have been introduced, with manifest advantage to the students, and they form a part of the regular curriculum of exercises,--as much so as the recitations in geography, grammar, or Greek. The good effect of the experiments, as shown in improved scholarship as well as increased bodily vigor, in the inst.i.tutions where the plan has been tried, will, it is hoped, lead to its universal adoption. We should then hear less frequently of parents being obliged to withdraw their children from school, because they become exhausted {34} or, perchance, have lost their health from intense and protracted mental application.

[Sidenote: 24. The result of gymnastics in our colleges and other inst.i.tutions of learning?]

24. Were gymnastics more common in our educational inst.i.tutions we should not so often witness the sad spectacle of young men and women leaving our colleges and seminaries, with finished educations it may be, but with const.i.tutions so impaired, that the life which should be devoted to the accomplishment of n.o.ble purposes must be spent in search of health. Spinal curvatures, which, according to the experience of physicians, are now extremely frequent, especially among ladies, would give place to the steady gait and erect carriage which G.o.d designed his human creatures should maintain.

25. All the exercises necessary for the proper development of the body may be obtained from the use of a few simple contrivances that every one can have at home, at little cost--less by far than is spent for useless toys.

Many of these may be made available in the parlor or chamber, though all exercises are far more useful in the open air. A small portion of the day thus spent will afford agreeable recreation as well as useful exercise. The Indian club, the wand, the ring, and the dumb-bells answer ordinary purposes very well. Ill.u.s.trations are here introduced of a few simple contrivances that may be useful for general exercises, and are specially suitable for persons with _weak spines_, or with spines that are the subject of lateral curvature.

26. One of the simplest appliances for strengthening the muscles of the spine, designed chiefly to exercise the muscles on either side of the spine, consists of two wooden handles attached to india-rubber cords, one of which is attached to a hook made fast in the ceiling, or in the top of the door-case; and the other to another hook fastened in the wall, door-post, or window-casing, about the height {35} of the shoulder. When traction is made with the left hand, it exercises the muscles on the left side of the spine, while those on the opposite side are left almost at rest, owing to the oblique direction given to the shoulders when the right hand grasps the horizontal cord. (This appliance will be understood by referring to Fig. 13.)

[Ill.u.s.tration: FIG. 11.]

[Ill.u.s.tration: FIG. 12.]

{36}

27. Fig. 11 shows an appliance consisting of two strong elastic cords, with handles, secured to a hook in the floor, so arranged that the patient has to stoop forward to reach them. On raising the body the spinal muscles are powerfully exercised. Fig. 12 shows other modes of using the elastic cords for strengthening the spine and chest.

[Ill.u.s.tration: FIG. 13.]

28. These various appliances have been combined so as to form a system of gymnastics suitable for parlor use; other appliances have been added by which the muscles of {37} the legs may be called into action as well as those of the spine and upper part of the body (Fig. 13). Combinations of cords suitable for particular cases may also be made, and by using one or several cords on the same hook, their power may be adapted to the strength of the most robust as well as to that of the invalid, or of the most delicate child. The entire apparatus is quite simple in its construction and inexpensive, requiring but little s.p.a.ce, and at the same time affording a great variety of exercises.