Popular Education. Ira Mayhew
to a beneficent Creator, than he who adopts an oblique posture. It was just remarked that "physical uprightness is next to moral." Physical obliquity, it may be added, is akin to moral. If they are not German-cousins, there can be little doubt but that, considered in all its bearings, the tendency of the former is to induce the latter.
Important as an erect posture and a well-developed chest are to gentlemen, they are in some respects even more so to the fairer sex; for, in addition to the advantages already considered, which both enjoy in common, these impart to them a peculiar charm, that to men of sense is far greater than pretty faces, which Nature has not given to all. "For a great number of years, it has been the custom in France to give young females, of the earliest age, the habit of holding back the shoulders, and thus expanding the chest. From the observations of anatomists lately made, it appears that the clavicle or collar bone is actually longer in females of the French nation than in those of the English. As the two nations are of the same race, as there is no remarkable difference in their bones, and this is peculiar to the sex, it must be attributed, as I believe, to the habit above mentioned, which, by the extension of the arms, has gradually produced an elongation of this bone. Thus we see that habit may be employed to alter and improve the solid bones. The French have succeeded in the development of a part in a way that adds to health and beauty, and increases a characteristic that distinguishes the human being from the brute."[9]
The Muscles.—The muscles consist of compact bundles of fleshy fibers, which are found in animals on removing the skin. They constitute the red fleshy part of meat, and give form and symmetry to the body. In the limbs they surround and protect the bones, while in the trunk they spread out and constitute a defensive wall for the protection of the vital parts beneath. The muscles have been divided into three parts, of which the middle and fleshy portion, called the belly, is most conspicuous. The other two parts are the opposite ends, and are commonly called the origin and insertion of the muscle. The origin is usually fastened to one bone, and the insertion is attached to another. By the contraction of the belly of the muscle, the insertion, which is movable, is drawn toward the origin, which is fixed, and brings with it the bone to which it is attached. This any one can see illustrated in bending the arm. The muscle which performs this function lies between the elbow and the shoulder. It is attached to the shoulder by its origin, and to one of the bones of the fore-arm, just below the elbow, by its insertion. By grasping the arm midway between the shoulder and the elbow with the opposite hand, and then bending the arm, the enlargement of the belly of the muscle by the contraction will be at once perceived. Then, by moving the hand down on the inside of the arm toward the elbow, the lessening muscle may be readily traced until it terminates in a tendon, of much less size than the muscle, but of great strength, which is inserted into the bone just below the elbow. As the fore-arm is drawn up, and especially if there be a weight in the hand, the tendon may be felt just within the elbow-joint, running toward the point of insertion. Extend the arm at the elbow, and the muscle on the outside of the arm will swell and become firm, while the inside muscle, and its tendon at the elbow, will be relaxed. This example well illustrates the principle on which all the joints of the system are moved. Those who are acquainted with mechanics will readily perceive that the action just described is an example of the "third kind of lever," where the power is applied between the weight and the fulcrum. The elbow is the fulcrum, the hand contains the weight, and the tendon, inserted into the bone just below the elbow, is the power. This kind of lever requires the power to be greater than the weight, and acts under what is called a mechanical disadvantage. What is lost in power, however, is compensated in increased velocity.
There are upward of four hundred muscles in the human body. Some of these are voluntary in their motions, as those I have described, while others are involuntary, as the action of the heart and the respiratory muscles. Had the action of these depended upon the will, as does the action of the muscles of locomotion, the circulation of the blood and the process of breathing would cease, and life would become extinct whenever sleep or any other cause should overcome the attention. Here, then, we have another beautiful illustration of the wisdom and beneficence of the Creator in so ordering that those muscles which are essential to the continuation of life shall perform their functions without the control or attention of the individual.
The study of the muscular system involves an exposition of the principles by which exercise should be regulated, and can scarcely fail to excite the attention of the general reader, and especially of those who, as parents or teachers, are interested in the education of the young.
The muscles enable us to move the frame-work of the system. Their chief purpose obviously is to enable us to carry into effect the various resolutions and designs which have been formed by the mind. But, while fulfilling this grand object, their active exercise is, at the same time, highly conducive to the well-being of many other important functions. By muscular contraction, the blood is gently assisted in its course through the smaller vessels to the more distant parts of the body; and by it the important processes of digestion, respiration, secretion, absorption, and nutrition are promoted; and by it the health of the whole body is immediately and greatly influenced. The mind itself is exhilarated or depressed by the proper or improper use of muscular exercise. It thus becomes a point of no slight importance to establish general principles by which that exercise may be regulated.
In every part of the animal economy, the muscles are proportioned in size and structure to the efforts required of them. Whenever a muscle is called into frequent use, its fibers increase in thickness within certain limits, and become capable of acting with greater force and readiness. On the other hand, when a muscle is little used, its volume and power decrease in a corresponding degree.
In order to secure the most beneficial results from exercise, reference should be had to the time at which it is taken. Those who are in perfect health may engage in it at almost any hour except immediately after a meal; but those who are not robust ought to confine their hours of exercise within narrower limits. To a person in full vigor, a good walk, or other brisk exercise before breakfast may be highly beneficial and exhilarating, while to an invalid or delicate person it will be likely to prove detrimental. In order to prove beneficial, exercise must be resorted to only when the system is sufficiently vigorous to be able to meet it. This is usually the case after a lapse of from two to four hours after a moderate meal. The forenoon, then, will generally be found the best time for exercise for persons whose habits are sedentary. If exercise be delayed till the system feels exhaustion from want of food, its tendency will be to dissipate the strength that remains and impair digestion; while, if taken at the proper time, it will invigorate the system and promote digestion. The reasons are obvious; for exercise of every kind causes increased action and waste in the organ, and if there be not materials and vigor enough in the system to keep up that action and supply the waste, nothing but increased debility can reasonably be expected.
Active exercise immediately before meals is injurious. The reasons are apparent, for muscular exercise directs a flow of blood and nervous energy to the surface and extremities; and it is an established law in physiology, that energetic action can not be kept up in two distant parts of the system at the same time. Hence, whenever a meal is taken immediately after vigorous exercise, the stomach is taken at disadvantage, and, from want of the necessary action in its vessels and nerves, is unable to carry on digestion with success. This is very obviously the case where the exercise has been severe or protracted.
Active exercise ought to be equally avoided immediately after a heavy meal, for then the functions of the digestive organs are in the highest state of activity. If the muscular system be called into vigorous action under such circumstances, it will cause a withdrawal of the vital stimuli of the blood and nervous influence from the stomach to the extremities, which can not fail greatly to retard the digestive process. In accordance with this well-established fact, there is a natural and marked aversion to active pursuits after a full meal. A mere stroll, which requires no exertion and does not fatigue, will not be injurious before or after eating; but exercise beyond this limit is at such times hurtful. All, therefore, who would preserve and improve their health, will find it to their advantage to observe faithfully this important law, otherwise they will deprive themselves of most of the benefits that are usually attendant upon judicious exercise. All, then, who are