P H Y S I O L O G Y ,
AND
H Y G I E N E.
CHAPTER I.
The Framework of the Body.
The Bones—Their Form and Composition—The Properties of Bone—The Skeleton—The Joints—The Spinal Column—The Growth of Bone—The Repair of Bone.
1. The framework of the body? The superstructure? Softness and delicacy of the organs? How protected?
1. The Bones.—The framework which sustains the human body is composed of the Bones. The superstructure consists of the various organs on which the processes of life depend. These organs are soft and delicately formed, and, if unprotected, would, in most cases, rapidly be destroyed when subjected to violence, however slight. The bones, having great strength and power of resistance, afford the protection required.
2. The more delicate the organ? Example in relation to the brain? The eye? The lungs? The services performed by the bones?
2. The more delicate the organ, the more completely does Nature shield it. For example: the brain, which is soft in structure, is enclosed on all sides by a complete box of bone; the eye, though it must be near the surface of the body to command an extensive view, is sheltered from injury within a deep recess of bone; the lungs, requiring freedom of motion as well as protection, are surrounded by a large case of bone and muscle. The bones serve other useful purposes. They give permanence of form to the body, by holding the softer parts in their proper places. They assist in movement, by affording points of attachment to those organs which have power of motion—the muscles.
3. Their shape and size? Of what composed? Possibility of being separated? Effect of fire? Of dilute acid?
3. The Form and Composition of the Bones.—Their shape and size vary greatly in different parts of the body, but generally they are arranged in pairs, one bone for each side of the body. They are composed of both mineral and animal substances, united in the proportion of two parts of the former to one of the latter; and we may separate each of these substances from the other for examination. First, if we expose a bone to the action of fire, the animal substance is driven off, or "burned out." We now find that, though the shape of the bone is perfectly retained, what is left is no longer tough, and does not sustain weight as before. Again, we may remove the mineral portion, which is a form of lime, by placing a bone into a dilute acid. The lime will be dissolved out, and the shape of the bone remain as before; but now its firmness has disappeared, and it may be bent without breaking.
4. Effect of deficiency of ingredient? Usefulness of the lime? Of the animal substance? Effect of their union? Condition, in youth? Old age?
4. If, for any reason, either of these ingredients is disproportionate in the bone during life, the body is in danger. The lime is useful in giving rigidity of form, while the animal substance insures toughness and elasticity. By their union, we are able to withstand greater shocks and heavier falls than would be possible with either alone. In youth, the period of greatest activity, the animal constituent is in excess: a bone then does not break so readily, but, when broken, unites with great rapidity and strength. On the other hand, the bones of old persons are more easily broken, and in some cases fail to unite. The mineral matter being then in excess, indicates that the period of active exertion is drawing to a close.
Fig. 1.—Section of Bone.
Fig. 2.
Structure of bone enlarged.
5. In what respect admirably fashioned? Its formation? Microscopic examination? The inference? "Line of beauty?"
5. The Structure of the Bones.—If we examine one of the long bones, which has been sawn through lengthwise, we observe that it is admirably fashioned for affording lightness as well as strength (Fig. 1). Its exterior is hard and resisting, but it is porous at the broad extremities, while through the central portion there is a cavity or canal which contains an oily substance, called marrow. Let us now take a thin section of bone, and examine it under the microscope; we discover that it is pierced by numerous fine tubes (Fig. 2), about which layers of bone-substance are arranged. Accordingly, though a bone be as hard as stone externally, it is by no means as heavy as stone, by reason of its light interior texture. Another element of power is found in the curved outline of the bones. The curved line is said to be "the line of beauty," as it certainly is the line of strength, and is uniformly employed in the bones whose position exposes them to accident.
Fig. 3.—The Skeleton
6. Number of bones? Skeleton? The skull? Chest? The trunk? The trunk and skull, how maintained? What of the arms? Legs?
6. The Skeleton.—The number of bones in the human body exceeds two hundred. When these are joined together in the proper places, they form what is termed the Skeleton (Fig. 3). It embraces three important cavities. The first, surmounting the frame, is a box of bone, called the skull; below this, is a bony case, or "chest;" and lower down is a bony basin, called the pelvis. The two latter compose the trunk. The trunk and skull are maintained in their proper relations by the "spinal column." Branching from the trunk are two sets of limbs: the arms, which are attached to the chest by means of the "collar-bone" and "shoulder-blade;" and the legs, directly joined to the lower part of the trunk.
7. Design of the cavities? Give the examples.
7. The cavities of which we have spoken, are designed for the lodgment and protection of the more delicate and perishable parts of the system. Thus, the skull, together with the bones of the face, shelters the brain and the organs of four senses—sight, hearing, smell, and taste. The chest contains the heart, lungs, and great blood-vessels, while the lower part of the trunk sustains the liver, stomach, and other organs.
8. Joint or articulation? Movable joints, how compacted? The ligaments of the movable joints? What is a sprain? Consequence of a serious sprain?
8. The Joints.—The point of union of two or more bones forms a joint or articulation, the connection being made in various ways according to the kind and amount of motion desired. The movable joints are compacted together by certain strong fibrous bands, called ligaments. These ligaments are of a shining, silvery whiteness, and very unyielding; so much so, that when sudden violence is brought to bear in the vicinity of a joint, the bone to which a ligament is attached may be broken, while the ligament itself remains uninjured. When this connecting material of the joints is strained or lacerated by an accident, a "sprain" is the consequence. An injury of this sort may be, and frequently is, quite as serious as the breaking of a bone.
Fig. 4.—Cells of Cartilage.
9. Office of the ligament? What must it have? How accomplished? Describe it. Synovia?
9. The ligament, then, secures firmness to the joint; it must also have flexibility and smoothness of motion. This is accomplished by a beautiful mechanism the perfection of which is only feebly imitated by the most ingenious contrivance of man. The ends of the bones are covered by a thin layer of cartilage, which being smooth and elastic, renders all the movements of the joint very easy. In addition to this, there is an arrangement introduced for "lubricating" the joint, by means of a delicate sac containing fluid. This fluid is constantly supplied in small quantities, but only so fast as it is used up in exercise. In appearance, it is not unlike the white of an egg, and hence its name synovia, or egg-like.
10. What do we observe as regards the composition of a joint? The ligament and cartilage? What varies? Example of the skull? Other examples? The ball-and-socket joint?
10. Thus, we observe, that two very different substances enter into the composition of a joint. The ligament, very unyielding, affords strength, while the cartilage, elastic and moist, gives ease and smoothness of motion. The amount of motion provided for varies greatly in different joints. In some there is none at all, as in the skull, where one bone is dove-tailed into another by what are termed sutures. Others have a hinge-like motion, such as those of the elbow, wrist, ankle, and knee; the most complete of these being the elbow-joint (Fig. 5). Belonging to another class, the ball-and-socket joint, is that at the shoulder, possessing a freedom of motion greater than any other in the body.
Fig. 5.—Elbow Joint. A, Bone of the arm; B, C, Bones of the fore-arm.
11. What is the spinal column? What does it connect and form? Joints of the vertebræ? Amount of motion? Result?
11. The Spinal Column.—The spinal column is often spoken of as the "back-bone," as if it were a single bone, while, in reality, it is composed of a chain of twenty-six small bones, called vertebræ. The spinal column is a wonderful piece of mechanism. It not only connects the important cavities of the body, as has already been shown, but, also, itself forms a canal, which contains the spinal cord. The joints of the vertebræ are remarkable for the thick layers of cartilage which separate the adjacent surfaces of bone. The amount of motion between any two of these bones is not great; but these little movements, taken together, admit of very considerable flexibility, in several directions, without endangering the supporting power of the column.
12. Elasticity of the frame? Protection of the brain from shocks? Tallness of persons? Effects of reclining?
Fig. 6—The Spinal Column.
12. The abundant supply of intervertebral cartilage has another important use, namely, it adds greatly to the elasticity of the frame. It is due, in part, to this elastic material, and in part to the frequent curves of the spine, that the brain and other delicate organs are protected from the shock of sudden falls or jars. During the day, the constant pressure upon these joints, while the body is erect, diminishes the thickness of the cartilages; so that a person is not so tall in the evening as in the morning. The effects of this compression pass away when the body reclines in a horizontal position.
13. Change in bone? Example—animal and madder. Rapidity of change in color? Waste and repair?
13. The Growth of Bone.—Bone, like all the other tissues of the body, is constantly undergoing change, old material being withdrawn, and new particles taking their place. This has been shown conclusively by experiments. If an animal be fed with madder—a red coloring matter—for a day or two, the bones soon become tinged; then, if the madder be discontinued for a few days, the original color returns. If, however, this material be alternately given and withheld, at short intervals, the bone will be marked by a succession of red and white rings. In very young animals, all the bones become colored in a single day; in older ones, a longer time is required. The process of waste and repair, therefore, is constantly taking place in this hard substance, and with astonishing rapidity.
14. The Repair of Bone.—Nature's provision for uniting broken bones is very complete. At first, blood is poured out around the ends of the bone, as a result of the injury. This is gradually absorbed, and gives place to a watery fluid, which, thickening from day to day, acquires, at the end of two weeks, the consistency of jelly. This begins to harden, by a deposit of new bone-substance, until, at the expiration of five or six weeks, the broken bone may be said to be united. It is, however, still fragile, and must be used carefully a few weeks longer. The process of hardening continues, and months must pass before the union can be said to be complete.
QUESTIONS FOR TOPICAL REVIEW.
PAGE 1. What useful purposes do the bones serve? [15], [16] 2. State what you can of the composition of the bones. [16] 3. Of the usefulness of lime in the bones. [16] 4. Of the usefulness of animal substance in the bones. [16] 5. State what you can of the structure of the bones. [17] 6. Of the strength belonging to the bones. [15], [16], [17] 7. What is meant by the human skeleton? [19] 8. Give a description of its construction. [19] 9. What is meant by a joint in the human frame? [19] 10. State what you can of the movable joints. [19], [20] 11. What office is performed by the ligaments of the joints? [19], [20] 12. What by the cartilage at the joints? [20] 13. What movable joints are there? [20], [21] 14. Describe the construction of the spinal column. [21] 15. What properties and powers does the spinal column possess? [21], [22] 16. When is a person taller than at other times? [22] 17. Give the reason for this. [22] 18. What can you state of the growth of bone? [22] 19. Describe the process by which a broken bone is repaired. [23]
Fig. 7.—The Muscles.
CHAPTER II.
The Muscles.
The Muscles—Flexion and Extension—The Tendons—Contraction—Physical Strength—Necessity for Exercise—Its Effects—Forms of Exercise—Walking—Riding—Gymnastics—Open-air Exercise—Sleep—Recreation.
1. What are the muscles? Their number? The design of most of them? Of a few?
1. The Muscles.— The great mass of the body external to the skeleton, is composed of the flesh, or Muscles, which largely determines its outline and weight. The muscles are the organs of motion. Their number is about four hundred, and to each of them is assigned a separate and distinct office. They have all been studied, one by one, and a name given to each, by the anatomist. Each is attached to bones which it is designed to move. A few are circular in form, and enclose cavities, the size of which they diminish by contraction.
Fig. 8.—Muscular Tissue.
a, b, Striped muscular fibres: c, The same more highly magnified.
2. The structure of flesh? Its color, etc.? The composition of the fibres? How marked?
2. If we examine a piece of flesh, we observe that it is soft, and of a deep red color. Its structure appears to be composed of layers and bundles of small fibres. Let us further examine these fibres under the microscope. We now discover that they are, in turn, made up of still finer fibres, of fibrillæ: these are seen in Fig. 8. The fibres are beautifully marked by parallel wavy lines, about ten thousand to an inch, which give the fibre its name of the striped muscular fibre. All of the voluntary muscles present this appearance.
3. Arrangement of the muscles? Their action? Flexion and extension? Action of the muscles when we stand erect?
3. Flexion and Extension.—The muscles are, for the most part, so arranged in pairs, or corresponding sets, that when motion is produced in one direction by one set, there is, opposite to it, another muscle, or group of muscles, which brings the limb back to its place. When they act alternately, a to-and-fro movement results. When a joint is bent, the motion is called flexion; and when it is made straight again, it is called extension. When both sets act equally, and at the same moment, no motion is produced, but the body or limb is maintained in a fixed position: this occurs when we stand erect. The muscles which produce extension are more powerful than those opposite to them.
Fig. 9.—A, Biceps muscle of the arm: B, C, Its tendons.
4. Kinds of muscles? The voluntary? Involuntary? The heart? Give the example. The hand? Arm?
4. The muscles are also distinguished, on the other hand, as the voluntary and involuntary muscles, according as they are, or are not, under the control of the will. The heart is an example of the involuntary variety. We cannot change its action in the least by an effort of the will. When we sleep, and the will ceases to act, the heart continues to beat without cessation. The voluntary muscles, on the other hand, are such as are used only when we wish or will to use them—as the muscles of the hand or arm (Fig. 9).
5. What are the tendons or sinews? Their strength? Color? Location? Tendon of Achilles? The fable? Muscles of the leg?
5. The Tendons.—Tendons, or sinews, are the extremities of muscles, and are compactly fastened upon bone. They are very strong, and of a silvery whiteness. They may be felt just beneath the skin, in certain parts of the body, when the muscles are being used, as at the bend of the elbow or knee. The largest tendon of the body is that which is inserted into the heel, called the tendon of Achilles, after the hero of the Grecian poet, the fable relating that it was at this point that he received his death-wound, no other part of his body being vulnerable. The muscles which extend into the leg unite to form a single and very powerful tendon, and enclose a small bone called the knee-pan, which, acting like a pulley, greatly increases their power, and at the same time protects the front of the knee-joint (Fig. 10).
Fig. 10.—View of Knee-joint. A, Thigh bone: B, Knee-pan: C, D, Leg bones.
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 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.
7. Contractility? Give the illustration. 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.
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.
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 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.
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.
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.
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, it is fair to suppose that our age has not so greatly degenerated in respect to physical strength.
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 classes of society, whose occupation confines them within doors, and requires chiefly brain-work.
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.
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 becomes hotter, as well as the parts beneath it, and the appetite 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.
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.
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.
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 especially, it is a very popular exercise, and is practised habitually by almost every class of society; by the wealthy as well as by those who have no carriages; by women as well as by men.
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.
20. Carriage-riding? Horseback-riding?
20. Carriage-riding, as a means of passive 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.
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, who, in times of danger, are the quickest to act and the most certain to do so with judgment.
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.
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 institutions 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 institutions 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 or, perchance, have lost their health from intense and protracted mental application.
24. The result of gymnastics in our colleges and other institutions of learning?
24. Were gymnastics more common in our educational institutions 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 constitutions so impaired, that the life which should be devoted to the accomplishment of noble 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 God 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. Illustrations 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 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.)
Fig. 11.
| PAGE | |
| 1. What useful purposes do the bones serve? | [15], [16] |
| 2. State what you can of the composition of the bones. | [16] |
| 3. Of the usefulness of lime in the bones. | [16] |
| 4. Of the usefulness of animal substance in the bones. | [16] |
| 5. State what you can of the structure of the bones. | [17] |
| 6. Of the strength belonging to the bones. | [15], [16], [17] |
| 7. What is meant by the human skeleton? | [19] |
| 8. Give a description of its construction. | [19] |
| 9. What is meant by a joint in the human frame? | [19] |
| 10. State what you can of the movable joints. | [19], [20] |
| 11. What office is performed by the ligaments of the joints? | [19], [20] |
| 12. What by the cartilage at the joints? | [20] |
| 13. What movable joints are there? | [20], [21] |
| 14. Describe the construction of the spinal column. | [21] |
| 15. What properties and powers does the spinal column possess? | [21], [22] |
| 16. When is a person taller than at other times? | [22] |
| 17. Give the reason for this. | [22] |
| 18. What can you state of the growth of bone? | [22] |
| 19. Describe the process by which a broken bone is repaired. | [23] |
Fig. 12.
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.
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 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 space, and at the same time affording a great variety of exercises.
Exercises that may be Practised on this Apparatus.
Exercise I. (Fig. 13).—Stand erect under the cords and place the heels together. Grasp the handles firmly, keeping the knees and elbows stiff, and pull downward and forward until the fingers nearly touch the toes. Return slowly to the erect position. Repeat.
Exercise II. (Fig. 13).—Stand erect, and having grasped the handles overhead firmly, separate them and bring them down slowly until they touch the sides: then return them slowly to the original position. Repeat.
Exercise III. (Fig. 13).—Stand erect, heels together, grasp the handles overhead, and charge forward with the right foot. Return to first position, and then charge with the left. Repeat, using the right and left foot alternately.
Exercise IV. (Fig. 13).—Stand erect, heels together. Grasp the handle overhead, and charge forward with the right foot, knee bent. Remain in this position and bring the arms down to the sides so that the arm and fore-arm may form a right angle. Still holding the handles, thrust forward, first the right hand and then the left, until the arm is straight. Repeat. Return to first position, then charge forward with the left foot, performing the same movements as before.
Exercise V. (Fig. 13).—In this exercise we change to the pulleys leading from the side posts, which can be used in several different ways. 1st. Stand erect, heels together, facing one of the posts, grasp the handle with the right hand, the arm being extended, then flex the fore-arm on the arm. Repeat. Perform the same movements with the left hand. 2d. Stand with back to the post; grasp the pulley behind with the right hand, then gradually bring the hand forward until it is extended in a straight line in front. Repeat. Perform the same exercise with the left hand.
Exercise VI. (Fig. 13).—This exercise is especially adapted to the legs. Stirrups are so arranged that they can be attached to the pulleys overhead, and can hang down to within three or four feet of the floor. Place the foot in the stirrup, and then press down until it touches the floor. Repeat. Exercise the left foot in the same way.
Exercise VII. (Fig. 13.)—This exercise requires a little attention in the adjustment of the apparatus. Under the pulleys in the floor are passed ropes which can be attached to the snap-hooks that hold the handles overhead. Stoop forward with the knees stiff, and take hold of the handles, and then raise the body to the erect position. Repeat.
Exercise VIII. (Fig. 13).—Sit on the floor or on a seat three or four inches high; bend forward, take hold of the handles, and perform the same movements that you would in rowing a boat.
Exercise IX. (Fig. 13).—The trapeze can now be let down; take hold of it with both hands, sustaining the weight of the body with the arms, then rotate the body first from right to left, then from left to right alternately. This exercise is especially suitable for females.
Exercise X. (Fig. 13).—Grasp the trapeze as before, bearing all the weight with the arms: then draw the body up slowly until you can place the chin over the bars. This requires strength of muscle, and might strain if done too violently; if slowly performed there is no danger.
These are but a few of the exercises that can be practised with this apparatus. As these become familiar they can easily be modified, and new ones can be arranged to meet the requirements of particular cases. Most of the exercises described can be practised with one hand so as to strengthen the muscles on one side.
29. Need of repose? How do we obtain rest? Alfred the Great? The eight-hour division of time?
29. Rest.—We cannot always be active: repose must succeed labor. We obtain this rest partly by suspending all exertion, as in sleep, and partly by a change of employment. It is said that Alfred the Great recommended that each day should be divided in the following manner: "Eight hours for work, eight hours for recreation, and eight hours for sleep." This division of time is as good as any that could now be made, if it be borne in mind that, when the work is physical, the time of recreation should be devoted to the improvement of the mind; and when mental, we should then recreate by means of physical exercise.
30. Cessation of voluntary activity? Temperature of the body? Consequence? Body and mind during sleep? Nutrition? Describe it. Consequences of insufficient sleep?
30. During sleep, all voluntary activity ceases, the rapidity of the circulation and breathing diminishes, and the temperature of the body falls one or two degrees. In consequence, the body needs warmer coverings than during the hours of wakefulness. During sleep, the body seems wholly at rest, and the mind is also inactive, if we except those involuntary mental wanderings which we call dreams. Nevertheless a very active and important physical process is going on. Nutrition, or the nourishing of the tissues, now takes place. While the body is in action, the process of pulling down predominates, but in sleep, that of building up takes place more actively. In this way we are refreshed each night, and prepared for the work and pleasures of another day. If sleep is insufficient, the effects are seen in the lassitude and weakness which follow. Wakefulness is very frequently the forerunner of insanity, especially among those who perform excessive mental labor.
31. Amount of sleep in different persons? Cases? Frederick the Great? Bonaparte? Instances of long deprivation of sleep?
31. All persons do not require the same amount of sleep, but the average of men need from seven to nine hours. There are well-authenticated cases where individuals have remained without sleep for many days without apparent injury. Frederick the Great required only five hours of sleep daily. Bonaparte could pass days with only a few hours of rest. But this long continued absence of sleep is attended with danger. After loss of sleep for a long period, in some instances, stupor has come on so profoundly, that there has been no awaking.
32. Instances of sailors? French soldiers? During torture?
32. There are instances related of sailors falling asleep on the gun-decks of their ships while in action. On the retreat from Moscow, the French soldiers would fall asleep on the march, and could only be aroused by the cry, "The Cossacks are coming!" Tortured persons are said to have slept upon the rack in the intervals of their torture. In early life, while engaged in a laborious country practice, the writer not unfrequently slept soundly on horseback. These instances, and others, show the imperative demand which nature makes for rest in sleep.
QUESTIONS FOR TOPICAL REVIEW.
PAGE 1. What can you state of the number and division of the muscles? [25], [26] 2. Describe the structure of the muscles. [25], [26] 3. Their arrangement in pairs and consequent action. [26] 4. What is the difference between the motion called flexion and that called extension? [26] 5. Describe their action, and state which are the more powerful. [26] 6. What is the difference between voluntary and involuntary muscles? [26] 7. Illustrate the difference between the two. [26] 8. State all you can of the tendons or sinews. [27] 9. What is meant by contraction of the muscles? [27], [28] 10. In how many and what ways may contraction be effected? [28] 11. What is stated of after-death contraction? [28] 12. Why cannot a muscle in life continue contracted a long time? [28] 13. How then can the constant beating of the heart be explained? [28] 14. How does the strength of a man compare with that of a horse? [29] 15. What can you state in relation to the relative strength of animals? [28], [29] 16. What, in relation to physical strength? [29] 17. What, in relation to physical degeneracy? [29], [30] 18. What, in relation to the importance of exercise? [30] 19. What is the effect of exercise upon the heart, skin, and appetite? [30], [31] 20. How does exercise affect the current of the body's circulation? [31] 21. How does judicious exercise affect the muscles? [31] 22. What is stated of violent and spasmodic exercise? [31] 23. Of the exercise of walking? [31], [32], [33] 24. Of running, leaping, and other modes of exercise? [32] 25. Of physical culture, in connection with out-door exercises? [33] 26. Of the importance of gymnastics in our schools and colleges? [33], [34] 27. Of the importance of rest from labor or exercise? [38], [39] 28. What processes take place during sleep? [39] 29. What effects follow insufficient sleep? [39]
CHAPTER III.
The Integument, or Skin.
The Integument—Its Structure—The Nails and Hair—The Complexion—The Sebaceous Glands—The Perspiratory Glands—Perspiration and its Uses—Importance of Bathing—Different kinds of Baths—Manner of Bathing—The Benefits of the Sun—Importance of Warm Clothing—Poisonous Cosmetics.
1. What is the skin? Parts directly beneath? What is shown?
1. The Integument.—The skin is the outer covering of the body. The parts directly beneath it are very sensitive, and require protection. This is shown whenever by accident the skin is broken, pierced, or torn off, the bared surface being very tender, and painful to the touch. Nature has provided the body with a garment that is soft, pliable, close-fitting, and very thin, and yet sufficiently strong to enable us to come in contact with the objects that surround us, without inconvenience or suffering.
2. Microscopic examination? What is the cutis? The cuticle? Their union? How separated? What further is said of the cuticle?
2. The Structure of the Skin.—When examined with the aid of the microscope, the skin is found to be made up of two layers—the outer and the inner. The inner one is called the cutis, or true skin; the outer one is the epidermis, or scarf-skin. The latter is also known as the cuticle. These two layers are closely united, but they may be separated from each other. This separation takes place whenever, from a burn, or other cause, a blister is formed; a watery fluid is poured out between the two layers, and lifts the epidermis from the true skin.
Of the two layers, the cuticle is the thinner in most parts of the body, and has the appearance of a whitish membrane. It is tough and elastic, is without feeling, and does not bleed, when cut. Examine it more closely, and we observe that it is composed of minute flat cells, closely compacted, and arranged layer upon layer.
3. Wearing out of the cuticle? What then? Variety in thickness of cuticle? How accounted for?
3. The outer layer is constantly being worn out, and falls from the body in the form of very fine scales. It is, also, continually forming anew on the surface of the inner layer. Its thickness varies in different parts of the body. Where exposed to use, it is thick, hard, and horn-like, as may be seen on the soles of the feet, or on the palms of the hands, especially of those who are accustomed to perform much manual labor. This is an admirable provision for the increased protection of the sensitive parts below the skin against all extraordinary exposure. Even the liabilities of these parts to injury, are thus kindly provided for by "the Hand that made us."
4. Location and office of the cutis? What further is said of it? Papillæ? Touch?
4. The cutis, or true skin, lies beneath the epidermis, and is its origin and support. It is firm, dense, elastic, very sensitive, and is freely supplied with blood-vessels. It is closely connected with the tissues below it, but may be separated by means of a sharp instrument. The surface of the cutis is not smooth, but is covered here and there with minute elevations, called papillæ. These are arranged in rows, along fine lines, or ridges, such as those which mark the palm and fingers; their number is about 80 to the square line (a line being one-twelfth of an inch). These papillæ contain the blood-vessels which carry the supply of blood needed by the ever-wasting skin. They contain nerves also, and are largely concerned in the sense of touch; hence they are particularly abundant where the touch is most delicate, as at the ends of the fingers.
5. What are the nails and hair? The growth of the nail? The rapidity of its growth? Accident to the nail?
Fig. 14.
a, b. The Root of a Hair.
1, 2, 3. The skin forming the hair sac. 4. Sebaceous glands. 5. The hair sac.
c. Transverse Section of a Hair.
5. The Nails and Hair.—These are appendages of the skin, and although very unlike the cuticle as it appears on the surface of the body, they are, in reality, modified forms of that layer of the skin. The nail grows from a fold of the cuticle at the root, and from the under surface. As fast as it is formed, it is constantly being pushed outward. The rapidity of its growth can be ascertained by filing a slight groove on its surface, and noticing how the space between it and the root of the nail increases, in the course of a few weeks. When the nail is removed by any accident, it will be replaced by a new one, if the root be not injured.
6. How are the hairs produced? Difference in their length?
6. The hairs are produced in a similar manner; the skin forming depressions, or hair sacs, from the bottom of which they grow and are nourished (Fig. 14). They are found, of greater or less length, on almost all parts of the surface, except the palms of the hands and soles of the feet. On certain parts of the body, they grow to great length; on other parts they are so short, that they do not rise beyond the hair sac in which they originate.
7. Root of the hair? Shaft? Firmness and softness of the hair?
7. The bulb, or root, from which the hair arises, is lodged in a small pouch, or depression in the skin. The shaft is the part which grows out beyond the level of the skin. Its growth is altogether in one direction, in length alone. The outer part of the hair is quite firm, while its interior is softer, and probably conveys the fluids by which it is nourished. The hair is more glossy in health than at other times.
8. Office of the nail? Of the hair? Give the illustrations.
8. The nail serves as a protection to the end of the finger, and also enables us to grasp more firmly, and to pick up small objects. The hair, too, is a protection to the parts it covers. On the head, it shields the brain from extremes of heat and cold, and moderates the force of blows upon the scalp. On the body, it is useful in affording a more extensive surface for carrying off the perspiration.
9. On what does the complexion depend? Light and dark races? Freckles?
9. Complexion.—In the deeper cells of the cuticle lies a pigment, or coloring matter, consisting of minute colored grains. On this pigment complexion depends; and, according as it is present in less or greater amount, occasions the difference of hue, that exists between the light and dark races of men, and between the blonde and brunette of the white races. Freckles are due to an irregular increase of coloring matter.
10. Influence of the sun? How illustrated? Jews?
10. The sun has a powerful influence over the development of this pigment, as is shown by the swarthy hue of those of the white race who have colonized in tropical climates. It is also well illustrated by the fact, that among the Jews who have settled in northern Europe, there are many who are fair complexioned, while those residing in India, are as dark as the Hindoos around them.
11. What is an Albino? Where are Albinos found?
11. An Albino is a person who may be said to have no complexion; that is, there is an entire absence of coloring matter from the skin, hair, and iris of the eye. This condition more frequently occurs among the dark races, and in hot climates, although it has been observed in almost every race and clime.
12. What are sebaceous glands? How do they act? Sebaceous glands of the face? How do they act?
12. Sebaceous Glands.—There are in the skin certain small glands, which produce an oily substance, called sebaceous matter. These glands are little rounded sacs, usually connected with the hair-bulbs; and upon these bulbs, they empty their product of oil, which acts as a natural and adequate dressing for the hair (4, Fig. 14). A portion of the sebaceous matter passes out upon the surface, and prevents the cuticle from becoming dry and hard. The glands situated upon the face and forehead, open directly upon the skin. In these, the sebaceous matter is liable to collect, and become too hard to flow off naturally.
13. Black points, called worms? Animalcules? Service performed by sebaceous matter?
13. These glands on the face and forehead frequently appear, on the faces of the young, as small black points, which are incorrectly called "worms." It is true, that occasionally living animalcules are found in this thickened sebaceous matter, but they can only be detected by the aid of the microscope. This sebaceous matter acts not only to keep the skin flexible, and furnish for the hair an oily dressing, but it especially serves to protect the skin and hair, from the acridity arising from the perspiration.
14. Perspiration? Sweat glands? Of what do they consist? Dimension of the tubes?
14. The Perspiratory Glands.—The chief product of the skin's action is the perspiration. For the formation of this, there are furnished countless numbers of little sweat-glands in the true skin. They consist of fine tubes, with globe-like coils at their deeper extremity. Their mouths or openings may be seen with an ordinary magnifying glass, upon the fine ridges which mark the fingers. These tubes, if uncoiled, measure about one-tenth of an inch in length. In diameter, they are about one three-hundredth of an inch, and upon certain parts of the body there are not far from three thousand of these glands to the square inch. Their whole number in the body is, therefore, very great; and, in fact, it is computed if they were all united, end to end, their combined measurement would exceed three miles.
15. What is sensible perspiration? Insensible perspiration?
15. The Sensible and Insensible Perspiration.—The pores of the skin are constantly exhaling a watery fluid; but, under ordinary circumstances, there is no moisture apparent upon the surface, for it evaporates as rapidly as it is formed. This is called insensible perspiration. Under the influence of heat or exercise, however, this fluid is excreted more abundantly, and appears on the surface in the form of minute, colorless drops. It is then termed sensible perspiration.
16. Components of perspiration? Upon what does perspiration depend? Amount of perspiration daily?
16. Water is the chief component of this fluid, there being about ninety-eight parts of water to two parts of solid matter. The quantity escaping from the body varies greatly, according to the temperature of the air, the occupation of the individual, and other circumstances. The average daily amount of this excretion, in the adult, is not far from thirty ounces, nearly two pints, or more than nine grains each minute.
17. What does perspiration set free from the blood? What other service does perspiration perform? Explain the process.
17. The Uses of the Perspiration.—Besides liberating from the blood this large amount of water, with the effete matter it contains, the perspiration serves to regulate the temperature of the body. That is to say, as evaporation always diminishes temperature, so the perspiration, as it passes off in the form of fine vapor, cools the surface. Accordingly, in hot weather this function is much more active, and the cooling influence increases in proportion. When the air is already charged with moisture, and does not readily receive this vapor of the body, the heat of the atmosphere apparently increases, and the discomfort therefrom is relatively greater.
18. Effect of interruption of excretion? What experiments are mentioned?
18. The importance of this excretion is shown by the effects that often follow its temporary interruption, namely, headache, fever, and the other symptoms that accompany "taking cold." When the perspiration is completely checked, the consequences are very serious. Experiments have been performed upon certain smaller animals, as rabbits, to ascertain the results of closing the perspiratory tubes. When they are covered by a coating of varnish impervious to water and gases, death ensues in from six to twelve hours; the attendant symptoms resembling those of suffocation.
19. Give the story in relation to the boy covered with gold foil.
19. It is related that, at the coronation of one of the Popes about three hundred years ago, a little boy was chosen to act the part of an angel; and in order that his appearance might be as gorgeous as possible, he was covered from head to foot with a coating of gold foil. He was soon taken sick, and although every known means were employed for his recovery, except the removal of his fatal golden covering, he died in a few hours.
20. Give the quotation. Perspiration?
20. The Importance of Bathing.—From these considerations, it is evident that health must greatly depend upon the free action of the skin. "He who keeps the skin ruddy and soft, shuts many gates against disease." When the watery portion of the perspiration evaporates, the solid matter is left behind on the surface. There, also, remain the scales of the worn-out cuticle, and the excess of sebaceous matter. In order to secure the natural action of the skin, these impurities require to be removed by the frequent application of water.
21. Ablution in warm climates? What advice is given?
21. In warm climates, and during hot weather, ablution should be more frequently practised. For a person in good health, a daily cold bath is advisable. To this should be added occasionally a tepid bath, with soap, water alone not being sufficient to remove impurities of a greasy nature. Soap facilitates this, by forming with such substances a chemical mixture, which is readily soluble in water, and is by it removed from the body.
22. Liebig's maxim? What further is added?
22. There is a maxim by the chemist Liebig, to the effect, that the civilization of a nation is high, in proportion to the amount of soap that it consumes; and that it is low, in proportion to its use of perfumes. In some degree, we may apply the same test to the refinement of an individual. The soap removes impurity; the perfume covers, while retaining it.
23. What is said about cold bathing?
23. The different kinds of Baths.—All persons are not alike able to use the cold bath. When the health is vigorous, and the system does not feel a shock after such a bath, a prompt reaction and glow upon the surface will show that it is beneficial. Where this pleasurable feeling is not experienced, but rather a chill and sense of depression ensues, we are warned that the system will not, with impunity, endure cold bathing.
24. What is said about warm bathing?
24. It should also be borne in mind, that the warm or hot bath cannot be continued so long, or repeated so frequently as the cold, on account of the enervating effect of unusual heat so applied to the body. For persons who are not in robust health, one warm bath each week is sufficient; this class should be careful to avoid every extreme in reference to bathing, clothing, and whatever greatly affects the action of the skin.
25. What is said about sea-bathing?
25. Sea-bathing is even more invigorating than fresh-water bathing. Those who cannot endure the fresh water, are often benefited by the salt-water baths. This may be accounted for, in part, by the stimulant action upon the surface, of the saline particles of the sea-water; but the exciting scenes and circumstances of sea-bathing also exert an important influence. The open-air exercise, the rolling surf, the genial weather, and usually the cheerful company, add to its intrinsic benefits.
26. What is said as to the time and manner of bathing?
26. Time and Manner of Bathing.—A person in sound health may take a bath at almost any time, except directly after a full meal. The most appropriate time is about three hours after a meal, the noon-hour being probably the best. For the cold bath, taken rapidly, no time is better than immediately after rising. Those beginning the use of cold baths should first try them at 70° Fahr., and gradually use those of a lower temperature. From five to twenty minutes may be considered the proper limit of time to remain in a bath; but a sensation of chilliness is a signal to withdraw instantly, whether at home, or at the sea-side. Two sea-baths may be taken daily; one of any other kind is sufficient.
27. Condition of the body when bathing? Direction, after bathing?
27. The body should be warm, rather than cold, when stepping into the bath; and after it, the skin should be thoroughly dried with a coarse towel. It is best to continue friction until there is a sensation of warmth or "glow" throughout the entire surface. This reaction is the test of the good effects of the bath. If reaction is still incomplete, a short walk may be taken, especially in the sunshine. It is very congenial, however, both to health and comfort, to rest for a short time directly after bathing, or to take some light refreshment. This is better than severe exercise or a full meal.
28. Bathing among the ancients? Baths of Rome?
28. Bathing among the Ancients.—The Romans and other nations of antiquity made great use of the vapor-bath as a means of preserving the health, but more particularly as a luxury. Their method was not unlike that employed in northern Europe at the present day. The public baths of Rome and other cities are among the grandest and most interesting monuments of ancient luxury and splendor; and from their ruins have been recovered some of the most beautiful works of art.
29. After the bath? Swimming among the ancients?
29. The Thermæ, as the baths of Rome were called, were of great extent, built very substantially, and ornamented at vast expense. They were practically free to all, the cost of a bath having been less than a cent. It is related that some persons bathed seven times a day. After the bath their bodies were anointed with perfumed oil. If the weather was fine, they passed directly from the Thermæ into the gymnasium, and engaged in some gentle exercise previous to taking the midday meal. Between two and three in the afternoon was the favorite hour for this ancient luxury. Swimming was a favorite exercise, and a knowledge of it was regarded as necessary to every educated man. Their common expression, when speaking of an ignorant person, was, "He can neither read nor swim."
30. The Sun-bath? The story of Pliny?
30. The Sun-Bath.—Some also were accustomed daily to anoint themselves, and lie or walk in apartments arranged for the purpose, with naked bodies exposed to the direct rays of the sun. There is an interesting allusion to this practice, in a letter of the younger Pliny to the historian Tacitus, describing the destruction of Pompeii by an eruption of Vesuvius. "My uncle," (Pliny the elder,) "was at that time in command of the fleet at Misenum. On the 24th of August, about one in the afternoon, my mother desired him to notice a cloud which seemed of unusual shape and dimensions. He had just returned from taking the benefit of the sun, and after a cold bath, and a slight repast, had retired to his study." Then follows a description of the destruction of Pompeii, and the death of the elder Pliny.
31. Benefit of the sun? Effect upon plants? Skin?
31. We may judge somewhat of "the benefits of the sun," by observing the unnatural and undeveloped condition of plants and animals which are deprived of light. Plants become blanched and tender; the fish of subterranean lakes, where no light enters, are undersized, and have no eyes; tadpoles kept in the dark do not develop into frogs; men growing up in mines are sallow, pale, and deformed. Besides the well-known effect of solar light in tanning the skin, it also makes it thicker and better able to resist exposure; though the complexion may be thereby injured, the health gains more than compensate for the loss of beauty. "To make good the loss of the lily, where the sun has cast his ray, he seldom fails to plant the rose."
32. Direction about clothing? Exposing limbs of children? Clothing, night and day?
32. Clothing.—In reference to clothing, we are far more apt, in our changeful climate, to use too little than too much. An aphorism of Boerhaave, worth remembering, if not of adopting, is, "We should put off our winter clothing on midsummer's day, and put it on again the day after." He also says, "Only fools and beggars suffer from the cold; the latter not being able to get sufficient clothes, the others not having the sense to wear them." The practice of exposing the limbs and necks of young children, for the alleged purpose of "hardening" them, is quite hazardous. It is not to be denied that some seem to be made tough by the process; but it is so only with the rugged children, the delicate ones will invariably suffer under this fanciful treatment. As has been stated before, the skin is constantly acting, by night as well as by day. It is therefore conducive both to cleanliness and comfort to change entirely the clothing on retiring for the night. The day-clothing should be aired during the night, and the bedding should be aired in the morning, for the same reason.
33. Cosmetics? Painters' colic?
33. Poisonous Cosmetics.—The extensive use of cosmetics for the complexion is a fertile source of disease. The majority of these preparations contain certain poisonous mineral substances, chiefly lead. Now, the skin rapidly absorbs the fine particles of lead, and the system experiences the same evil effects that are observed among the operatives in lead works and painters, namely, "painters' colic," and paralysis of the hands, called "wrist-drop."
34. Certain hair-dyes also contain lead, together with other noxious and filthy ingredients. These do not work as great harm as the cosmetics, since they are purposely kept away from the skin, but they rob the hair of its vitality. Eye-washes, too, are made from solutions of lead, and many an eye has been ruined by their use. They deposit a white metallic scale on the surface of the eye, which becomes a permanent obstruction to the vision.
QUESTIONS FOR TOPICAL REVIEW.
PAGE 1. What are the characteristics of the skin, and what office does it perform? [41] 2. What can you state of the structure of the skin? [41] 3. Describe the cuticle and tell its use. [41], [42] 4. Describe the cutis or true skin and tell its use. [42] 5. What can you state of the nature and growth of the nail? [42], [43] 6. Of the nature and growth of the hair? [42], [43], [44] 7. Of the offices performed by the nails and hair? [44] 8. How is the difference in complexion in different persons accounted for? [44] 9. How is the presence of freckles accounted for? [44] 10. How does Nature provide a dressing for the hair? [44], 45 11. What other service do the sebaceous glands perform? [45] 12. State what you can of the perspiratory glands. [45] 13. What is the difference between sensible and insensible perspiration? [46] 14. State the uses and importance of perspiration. [46], 47 15. What impurities gather naturally on the skin? [47] 16. Repeat what is said of the importance of bathing. [47], [48] 17. When should we indulge in cold, warm, and sea bathing? [48], [49] 18. What is the effect in each case? [48] 19. What directions are given as to the time and manner for bathing? [49] 20. What is related of bathing among the ancients? [49], [50] 21. What is related to show the antiquity of sun-bathing? [50] 22. What are the effects of sun-bathing? [50], [51] 23. What directions are given in relation to clothing the body? [51] 24. What can you state of poisonous cosmetics? [51], [52] 25. Of hair-dyes and eye-washes? [52]
CHAPTER IV.
The Chemistry of Food.
The Source of Food—Inorganic Substances—Water—Salt—Lime—Iron—Organic Substances—Albumen, Fibrin, and Casein—The Fats or Oils—The Sugars, Starch, and Gum—Stimulating Substances—Necessity of a Regulated Diet.
Exercise I. (Fig. 13).—Stand erect under the cords and place the heels together. Grasp the handles firmly, keeping the knees and elbows stiff, and pull downward and forward until the fingers nearly touch the toes. Return slowly to the erect position. Repeat.
Exercise II. (Fig. 13).—Stand erect, and having grasped the handles overhead firmly, separate them and bring them down slowly until they touch the sides: then return them slowly to the original position. Repeat.
Exercise III. (Fig. 13).—Stand erect, heels together, grasp the handles overhead, and charge forward with the right foot. Return to first position, and then charge with the left. Repeat, using the right and left foot alternately.
Exercise IV. (Fig. 13).—Stand erect, heels together. Grasp the handle overhead, and charge forward with the right foot, knee bent. Remain in this position and bring the arms down to the sides so that the arm and fore-arm may form a right angle. Still holding the handles, thrust forward, first the right hand and then the left, until the arm is straight. Repeat. Return to first position, then charge forward with the left foot, performing the same movements as before.
Exercise V. (Fig. 13).—In this exercise we change to the pulleys leading from the side posts, which can be used in several different ways. 1st. Stand erect, heels together, facing one of the posts, grasp the handle with the right hand, the arm being extended, then flex the fore-arm on the arm. Repeat. Perform the same movements with the left hand. 2d. Stand with back to the post; grasp the pulley behind with the right hand, then gradually bring the hand forward until it is extended in a straight line in front. Repeat. Perform the same exercise with the left hand.
Exercise VI. (Fig. 13).—This exercise is especially adapted to the legs. Stirrups are so arranged that they can be attached to the pulleys overhead, and can hang down to within three or four feet of the floor. Place the foot in the stirrup, and then press down until it touches the floor. Repeat. Exercise the left foot in the same way.
Exercise VII. (Fig. 13.)—This exercise requires a little attention in the adjustment of the apparatus. Under the pulleys in the floor are passed ropes which can be attached to the snap-hooks that hold the handles overhead. Stoop forward with the knees stiff, and take hold of the handles, and then raise the body to the erect position. Repeat.
Exercise VIII. (Fig. 13).—Sit on the floor or on a seat three or four inches high; bend forward, take hold of the handles, and perform the same movements that you would in rowing a boat.
Exercise IX. (Fig. 13).—The trapeze can now be let down; take hold of it with both hands, sustaining the weight of the body with the arms, then rotate the body first from right to left, then from left to right alternately. This exercise is especially suitable for females.
Exercise X. (Fig. 13).—Grasp the trapeze as before, bearing all the weight with the arms: then draw the body up slowly until you can place the chin over the bars. This requires strength of muscle, and might strain if done too violently; if slowly performed there is no danger.
These are but a few of the exercises that can be practised with this apparatus. As these become familiar they can easily be modified, and new ones can be arranged to meet the requirements of particular cases. Most of the exercises described can be practised with one hand so as to strengthen the muscles on one side.
| PAGE | |
| 1. What can you state of the number and division of the muscles? | [25], [26] |
| 2. Describe the structure of the muscles. | [25], [26] |
| 3. Their arrangement in pairs and consequent action. | [26] |
| 4. What is the difference between the motion called flexion and that called extension? | [26] |
| 5. Describe their action, and state which are the more powerful. | [26] |
| 6. What is the difference between voluntary and involuntary muscles? | [26] |
| 7. Illustrate the difference between the two. | [26] |
| 8. State all you can of the tendons or sinews. | [27] |
| 9. What is meant by contraction of the muscles? | [27], [28] |
| 10. In how many and what ways may contraction be effected? | [28] |
| 11. What is stated of after-death contraction? | [28] |
| 12. Why cannot a muscle in life continue contracted a long time? | [28] |
| 13. How then can the constant beating of the heart be explained? | [28] |
| 14. How does the strength of a man compare with that of a horse? | [29] |
| 15. What can you state in relation to the relative strength of animals? | [28], [29] |
| 16. What, in relation to physical strength? | [29] |
| 17. What, in relation to physical degeneracy? | [29], [30] |
| 18. What, in relation to the importance of exercise? | [30] |
| 19. What is the effect of exercise upon the heart, skin, and appetite? | [30], [31] |
| 20. How does exercise affect the current of the body's circulation? | [31] |
| 21. How does judicious exercise affect the muscles? | [31] |
| 22. What is stated of violent and spasmodic exercise? | [31] |
| 23. Of the exercise of walking? | [31], [32], [33] |
| 24. Of running, leaping, and other modes of exercise? | [32] |
| 25. Of physical culture, in connection with out-door exercises? | [33] |
| 26. Of the importance of gymnastics in our schools and colleges? | [33], [34] |
| 27. Of the importance of rest from labor or exercise? | [38], [39] |
| 28. What processes take place during sleep? | [39] |
| 29. What effects follow insufficient sleep? | [39] |
| PAGE | |
| 1. What are the characteristics of the skin, and what office does it perform? | [41] |
| 2. What can you state of the structure of the skin? | [41] |
| 3. Describe the cuticle and tell its use. | [41], [42] |
| 4. Describe the cutis or true skin and tell its use. | [42] |
| 5. What can you state of the nature and growth of the nail? | [42], [43] |
| 6. Of the nature and growth of the hair? | [42], [43], [44] |
| 7. Of the offices performed by the nails and hair? | [44] |
| 8. How is the difference in complexion in different persons accounted for? | [44] |
| 9. How is the presence of freckles accounted for? | [44] |
| 10. How does Nature provide a dressing for the hair? | [44], 45 |
| 11. What other service do the sebaceous glands perform? | [45] |
| 12. State what you can of the perspiratory glands. | [45] |
| 13. What is the difference between sensible and insensible perspiration? | [46] |
| 14. State the uses and importance of perspiration. | [46], 47 |
| 15. What impurities gather naturally on the skin? | [47] |
| 16. Repeat what is said of the importance of bathing. | [47], [48] |
| 17. When should we indulge in cold, warm, and sea bathing? | [48], [49] |
| 18. What is the effect in each case? | [48] |
| 19. What directions are given as to the time and manner for bathing? | [49] |
| 20. What is related of bathing among the ancients? | [49], [50] |
| 21. What is related to show the antiquity of sun-bathing? | [50] |
| 22. What are the effects of sun-bathing? | [50], [51] |
| 23. What directions are given in relation to clothing the body? | [51] |
| 24. What can you state of poisonous cosmetics? | [51], [52] |
| 25. Of hair-dyes and eye-washes? | [52] |
1. The term food? Source of food? Need of preparing food?
1. The Source of Food.—The term food includes all those substances, whether liquid or solid, which are necessary for the nourishment of the body. The original source of all food is the earth, which the poet has fitly styled the "Mother of all living." In her bosom, and in the atmosphere about her, are contained all the elements on which life depends. But man is unable to obtain nourishment directly from such crude chemical forms as he finds in the inorganic world. They must, with a few exceptions, be prepared for his use, by being transformed into new and higher combinations, more closely resembling the tissues of his own body.
2. Usefulness and hurtfulness of plants? What then must man do? Parts of the same plant or tree?
2. This transformation is effected, first, by the vegetable world. But all plants are not alike useful to man; while some are absolutely hurtful. Accordingly, he must learn to discriminate between that which is poisonous and that which is life-supporting. Again, all parts of the same plant or tree are not alike beneficial: in some, the fruit, in others, the leaves, and in others, the seeds only are sufficiently refined for his use. These he must learn to select; he must also learn the proper modes of preparing each kind for his table, whether by cooking or other processes.
3. Certain forms of vegetable creation? Example of the bee? Cattle? The inference?
3. Again, certain forms of the vegetable creation which are unfit, in their crude state, for man's food, and which he rejects, are chosen as food by some of the lower animals, and are, by them, made ready for his use. Thus the bee takes the clover, that man cannot eat, and from it collects honey. The cattle eat the husks of corn and the dried grass, that are by far too coarse for man, and in their own flesh convert them into tissues closely resembling his muscular tissue. In this way, by the aid of the transforming processes of the vegetable and animal creations, the simple chemical elements of the mineral kingdom are elaborated into our choice articles of food.
4. What classification? Define organic substances. Inorganic. Organic, how spoken of? The inorganic? Water and salt?
4. Inorganic Substances.—The substances we use as food are classified as organic and inorganic. By organic substances are meant those derived from living forms, such as vegetables and animals. Inorganic substances are those simpler inanimate forms which belong to the mineral kingdom. The former alone are commonly spoken of as food, but the latter enter very largely into the constitution of the body, and must therefore be present in our food. With the exception of two articles, water and common salt, these substances only enter the system when blended with organic substances.
5. Water in physiology? Where found? Computation? Water in the teeth? Muscle, tendons, and ligaments? How ascertained? Water in the fluids of the body? What is the advantage?
5. Water.—Water, from a physiological point of view, is the most important of all the articles of food. It is everywhere found in the body, even in the bones and the teeth. It has been computed that as large a proportion as two-thirds of the body is water. The teeth, the densest of the solids in the human system, contain ten per cent. of water. The muscles, tendons, and ligaments are more than half water; for it is found that they lose more than half their weight when dried with moderate heat. But it is in the fluids of the body that water is found most abundantly. It gives to them the power of holding a great variety of substances in solution, and is the great highway by which new supplies are conveyed to the point where they are required, and by which old particles of matter, that have served their uses, are brought to the outlets of the body to be thus removed from the system.
6. Length of time man can do without food or water? Give the comparison? Bulk of drinks? Constituent of meats, etc.? Fruits?
6. Man can remain a longer time without solid food than without water. He may be deprived of the former for ten to twelve hours without great suffering, but deprivation of water for the same length of time will produce both severe pain and great weakness. The food should contain not less than two parts of water to one of solid nutriment. Water constitutes the great bulk of all our drinks, and is also a large constituent of the meats, vegetables, and fruits which come upon the table. Fruits, especially, contain it in great abundance, and, in their proper season, furnish most agreeable and refreshing supplies of the needed fluid.
7. Salt, how obtained? Where found? In the human body? Importance of salt? What else can you state of the value of salt?
7. Common Salt.—Salt, or sodium chloride, as an article of food, is obtained chiefly from the mineral kingdom; although plants contain it in small quantities, and it is also found in the tissues of nearly all animals used as food. In the human body, it is an ingredient of all the solids and fluids. The importance of salt to animal life in general, is shown by the great appetite for it manifested by domestic animals, and also by the habitual resort of herds of wild beasts to the "salt-licks" or springs. In those parts of the world where salt is obtained with difficulty, man places a very high price upon it.
8. Experiments upon animals?
8. Experiments upon domestic animals show that the withdrawal of salt from their food, not only makes their hides rough and causes the hair to fall out, but also interferes with the proper digestion of food. If it be withheld persistently, they become entirely unable to appropriate nourishment, and die of starvation.
9. Salt, how taken into the system? Its use in cooking? Consumption?
9. Salt is usually taken into the system in sufficient quantities in our food. Even the water we drink often has traces of it. The habitual use of much salt in cooking, or as a seasoning at the table, is not wise; and while it may not lead to consumption, as some writers declare, it is a bad habit in itself, and leads to the desire for other and more injurious condiments.
10. Lime in the bones? What does it impart? Chief ingredient of the bones and teeth? Where else found?
10. Lime.—This is the mineral substance which we have spoken of before as entering very largely into the composition of the bones. It is the important element which gives solidity and permanence to the framework upon which the body is built. Calcium tri-phosphate, or "bone-earth," is the chief ingredient of the bones and teeth, but is found in the cartilages and other parts of the body in smaller quantities.
11. How does lime find its way into the body? Early life? Effect of its derivation?
11. How does this substance find its way into the body? Meat, milk, and other articles obtained from the animal kingdom contain it, and it is abundantly stored away also in the grains from which our bread is made, in wheat, rye, and Indian corn. In early life, while the body is growing, the supplies of this substance should be carefully provided. The evil effects of the deprivation of it are too often and painfully evident in the softening of the bones, and in the predisposition to curvature of the spine—deformities which are most deplorable and which continue through life.
12. Iron, its abundance and diffusion? Where found? What part of the blood is it? How supplied to the system? In case of loss of blood or wasting disease?
12. Iron.—This substance is probably the most abundant and widely diffused of the metals. It is found in most of the vegetables, and is a very important component of animal tissues. It enters into the composition of human blood in about one part per thousand. Ordinarily, the food conveys to the system enough iron for its use, but it must sometimes be introduced separately as a remedy, especially after great loss of blood, or after some wasting disease. Under its influence the blood seems to be rapidly restored, and a natural color of the lips and skin replaces the pallor caused by disease.
13. Soda, potash, and magnesia? How do they occur?
13. Other Inorganic Substances.—In addition to the substances mentioned, the mineral kingdom supplies compounds of soda, potash, and magnesia, which are essential for the use of the body. They occur in small quantities in the body, and enter it in combination with the various articles of diet.
14. Organic substances, whence derived? What do they comprise? Groups?
14. Organic Substances.—These substances are derived from the vegetable and animal creations. They comprise all those articles which are commonly spoken of as "food," and which are essential to sustain the body in life and strength. They are divided into three groups, namely: the Albuminoid substances, the Fats, and Sugars.
15. The Albuminoid class, includes what? These compounds constitute what? The food? Their importance? Their properties?
15. The Albuminoids.—This class includes three important nutritive substances—(1) Albumen, which gives it its name; (2) Fibrin, including gluten; and (3) Casein. These compounds constitute a large part of the human body, and the food contains them in proportionally large quantities. Their importance is so great, and the system so promptly suffers from their absence, that they have been styled the "nutritious substances." The properties which they hold in common are, that they do not crystallize, and have a jelly-like form, except when heat is applied to them, when they harden, or coagulate.
16. Decomposition? Effect of cold? Illustrations? Elephants?
16. They likewise decompose, or putrefy, under the influence of warmth and moisture. Hence the decay of all dead animal tissues. Cold arrests this process. It is well known that milk, eggs, and the like, "keep" much longer in winter than at other seasons. The bodies of elephants, caught in the ice many hundred years ago, are occasionally borne by the icebergs to the coast of Siberia, completely frozen, but preserved almost perfectly in form and limb.
17. In what substances does albumen exist? What further is said of the egg?
17. Albumen exists in milk, meat, the grains, and the juices of many plants; but the purest form is obtained from the white of egg. When we consider that an egg is composed chiefly of albumen and water—namely, six parts in seven; and when we also consider the numerous, diverse, and complex tissues—the muscles, bones, internal organs, bill, claws, and feathers—with which the chick is equipped on leaving his shell, we are impressed with the importance of these apparently simple constituents of the food and body.
18. Fibrin, gluten, clotting of the blood?
18. Fibrin is derived from meats, and exists in the blood both of man and the lower animals. Gluten, or vegetable fibrin, resembles closely true fibrin, and is abundantly furnished in wheat and other grains from which flour is commonly made. Animal fibrin coagulates spontaneously when it is removed from the body, and thus causes the "clotting" of the blood.
19. Casein? Its coagulation? Effect of rennet? Making of cheese?
19. Casein is the curdy ingredient of milk, and a highly important food-substance. Its coagulation in milk takes place not from heat, but by the addition of an acid, and also when milk becomes sour from exposure to the air. It is commonly effected, however, by introducing a piece of rennet, a preparation made from a calf's stomach. The curds, or casein, may then be separated from the whey, and made into cheese, by pressing it sufficiently to drive off the water.
20. What are the fats? The oils? How supplied? How alike? Emulsifying? Example? How do we know it?
20. The Fats or Oils.—This is the second group of organic foods. Those which are more solid are called fats: the more fluid ones are the oils. Oleaginous substances are supplied in both animal and vegetable food; but, from whatever source derived, they are chemically much alike. They are insoluble in water, and yet they unite readily with the watery fluids of the body, and are by them conveyed to its various parts for their nourishment. This is due to their property of "emulsifying;" that is, they are held in suspension, in a finely divided state, in water. Ordinary milk is an example of an emulsion. We know that it contains fat; for butter is obtained from it, and, under the microscope, the minute oil-globules may be distinctly seen.
21. Whence are fatty articles of food derived?
21. In our country and climate, and also in colder climates, fatty articles of food are principally derived from the animal creation, such as meat or flesh, milk and butter. But most of the bread-stuffs contain more or less fat or oil; Indian meal as much as nine parts in a hundred.
22. Appetite of persons in cold climates? What do they require? Upon what must they rely? Why? The Esquimaux? Laplander? Olive and palm?
22. Among persons living in cold climates, the appetite for oleaginous food is especially eager; and they require large quantities of it to enable them to resist the depressing influences of cold. Since vegetation is scanty and innutritious, and the waters of the frozen regions abound in animal life, they must rely wholly upon a diet derived from the latter source. The Esquimaux consumes daily from ten to fifteen pounds of meat or blubber, a large proportion of which is fat. The Laplander will drink train-oil, and regards tallow-candles as a great delicacy. In hot climates, on the contrary, where flourish the olive and the palm, this kind of food may be obtained from vegetable sources in abundant quantities.
23. Which are the third of the organic groups? What do they embrace? Points of resemblance?
23. The Sugars, or the Saccharine Substances.—These constitute the third, and last, group of the organic substances, which are employed as food. This group embraces, in addition to the different kinds of Sugar, the varieties of starch and gum, from whatever source derived. The two substances last named do not, at first sight, present many points of similarity to sugar; but they closely resemble it in respect to their ultimate chemical composition, being made up of the same elements, in nearly the same proportions. And their office in the system is the same, since they are all changed into sugar by the processes of digestion.
24. Origin of the sugars? Ordinary sugar? Beetroot? Maple-sugar? Grape-sugar? Cane-sugar?
24. Sugar is chiefly of vegetable origin; the animal varieties being obtained from honey and milk. The most noticeable characteristic of this substance is its agreeable, sweet taste, which makes it everywhere a favorite article of food. But this quality of sweetness is not possessed by all the varieties of sugar in the same degree; that obtained from milk, for instance, has a comparatively feeble taste, but rather imparts a gritty feeling to the tongue. The other important properties of sugar are, its power to crystallize when evaporated from watery solutions, such as the juices of many plants; a tendency to ferment, by which process alcohol is produced; and a ready solubility in water. This latter quality renders it very easy of digestion, and more so than any other of the saccharine group. It is computed that the annual production of sugar, in all parts of the world, is more than one million of tons. The kind of sugar that is in ordinary use, in this country, is prepared from the juice of the sugar-cane, which contains eighteen per cent. of sugar. In France it is manufactured from the beet root, which holds about nine per cent.; the maple-tree of our climate yields a similar sugar. The sweet taste of fruits is due to the presence of grape-sugar: the white grains seen on raisins belong to this variety. Cane-sugar is more soluble than the latter, and has twice the sweetening power.
Fig. 15.—Granules of Potato Starch.
25. Starch, how widely distributed? Its qualities? Its constituents? Its solubility?
25. Starch.—This is the most widely distributed of the vegetable principles. It is tasteless, inodorous, and does not crystallize. It consists of minute rounded granules, which, under the microscope, reveal a somewhat uniform structure (Fig. 15). Starch will not dissolve in cold water, but in boiling water the small grains burst open, and may then be dissolved and digested.
26. How much starch in bread-stuffs? In rice? Unripe fruits? Ripe fruits?
26. The bread stuffs, wheat, corn, and rye flours, are more than one-half starch. Rice, which is the "staff of life" to one-third of the human family, contains eighty per cent. Unripe fruits have much starch in them, which renders them indigestible when eaten uncooked; for the grains of raw starch are but slightly acted upon within the body. But, under the potent chemistry of the sun's ray, this crude material is converted into sugar. Thus are the fruits prepared by the careful hand of Nature, so that when ripe they may be freely used without further preparation.
27. Gum, where found? Its composition? Gum Arabic?
27. Gum is commonly found in those articles which also contain starch; and has the same chemical composition as the latter, but is much less nutritious. In the East, gum-arabic and similar substances are largely employed as food. Persons who travel by caravan across vast, sandy deserts, find such substances well adapted to their wants, since they are not perishable, and are easily packed and carried.
28. The three classes of food principles? What besides? What is said of them? Name the articles not nutritious.
28. Stimulating Substances.—The three classes of food-principles already considered—the Albuminoids, the Fats, and the Sugars—comprise all the more important organic ingredients of our food. There are, besides, a great variety of coloring and flavoring matters that stimulate or increase the appetite for food by appealing to the eye and taste; but they are not nutritious, and are quickly separated from the truly useful substances, and do not long remain in the body. Among these may be classed spices, flavors of fruits, tea, coffee, and vegetable acids.
29. What is said of experiments that have been tried?
29. Necessity of a Regulated Diet.—A great variety of experiments have been tried in order to test the relative value of the different nutritive principles. They have been practised to some extent upon man, but chiefly upon those inferior animals which require a similar diet to man.
30. What has been demonstrated in the first place? Example? Second demonstration? Example? Give the illustration in relation to convertibility.
30. By this means it has been demonstrated that—first, when any one of these substances is eaten exclusively, the body is imperfectly nourished, and life is shortened. Dogs fed exclusively upon either albumen, fat, or sugar, soon die of starvation. Second, a diet long deprived of either of these principles, is a fertile cause of disease; for example, on ship-board, where fresh vegetables are not dealt out for a long period, scurvy becomes prevalent among the sailors. They are, however, to a certain extent mutually convertible, and thus the missing article is indirectly supplied. For instance, sugar changes to fat in the body; and hence, as is well known, the "hands" on a sugar plantation grow fat during the sugar season, by partaking freely of the ripened juices of the cane.
31. That is the best diet therefore which contains some of each of these principles, in due proportion; and that is the worst which excludes the most of them. The cravings and experience of man had unerringly guided him to a correct regulation of his diet, long before the chemistry of food was understood; so that his ordinary meals long ago combined these various principles, the necessity and value of which are now explained.
QUESTIONS FOR TOPICAL REVIEW.
PAGE 1. What is understood by the term food? [53] 2. What can you state in relation to the source of food? [53] 3. What discriminations and selections are necessary? [53], 54 4. How can you tell the organic from the inorganic substances? [54] 5. What relative position does water hold as an article of food? [54] 6. In what parts of the body is water found? [54], [55] 7. In what articles that we eat is it found? [55] 8. If you were required to go without water or solid food for a number of days, which would you prefer to have, and why? [55] 9. What can you state of the importance of salt as an article of food? [55], [56] 10. How abundant is salt, and how does it find its way into the human system? [55], [56] 11. What can you state of the importance of lime in the body? [56] 12. What, of the importance of iron? [56], [57] 13. What further is stated of other inorganic substances? [57] 14. What in relation to organic substances? [57] 15. What can you state in relation to the albuminoids? [57], [58] 16. What, in relation to albumen? [58] 17. What, in relation to casein? [58], [59] 18. In relation to the fats or oils, and how generally consumed? [59], [60] 19. What do we understand by the sugars or saccharine substances? [60] 20. State what you can of sugar—its origin and various qualities. [60], [61] 21. Of starch—its varieties and qualities. [61] 22. Of the abundance of starch, and its importance as a food principle. [61] 23. What is stated in relation to stimulating substances? [62] 24. Of the necessity for regulation in diet? [62], [63]
CHAPTER V.
FOOD AND DRINK.
Necessity for Food—Waste and Repair—Hunger and Thirst—Amount of Food—Renovation of the Body—Mixed Diet—Milk—Eggs—Meat—Cooking—Vegetable Food—Bread—The Potato—Fruits—Purity of Water—Action of Water upon Lead—Coffee, Tea, and Chocolate—Effects of Alcohol.
1. What follow activity? Examples? Necessity for food?
1. Necessity for Food.—Activity is everywhere followed by waste. The engine uses up coal and water to produce motion, the stream wears away its bank, the growing corn-blade draws tribute from the soil. When the human body acts, and it is always in action during life, some of its particles are worn out and thrown off. This waste must constantly be repaired, or the body suffers. In this fact is seen the necessity for food. The particles, thus worn out, being henceforth useless, are removed from the body. Our food and drink are rapidly transformed into a new supply of living, useful material, to be in turn used up and replaced by a fresher supply.
2. Give the theory in relation to waste and repair.
2. Waste and Repair.—In this way the healthful body, though always wasting, is always building up, and does not greatly change in size, form, or weight. At two periods of life the processes of waste and repair are not exactly balanced. In early life the process of building up is more active, and in consequence the form is plump, and the stature increases. Repair now exceeds waste. On the other hand, when old age comes on, the wasting process is more active, the flesh and weight diminish, the skin falls in wrinkles, and the senses become dull. Only during the prime of life—from about twenty to sixty years of age—is the balance exact between loss and gain.
3. System deprived of food? Warning? What is the pain? How proved?
3. Hunger and Thirst.—When the system is deprived of its supply of solid food during a longer time than usual, nature gives warning by the sensation of hunger, to repair the losses that have taken place. This sensation or pain appears to be located in the stomach, but it is really a distress of the system at large. Let a sufficient quantity of nourishment be introduced into the system in any other way than by the mouth, and it will appease hunger just as certainly as when taken in the usual manner.
4. Feeling of thirst? Seat of the pain? How proved? Time a person can exist without food?
4. The feeling of thirst, in like manner, is evidence that the system is suffering from the want of water. The apparent seat of the distress of thirst is in the throat; but the injection of water into the blood-vessels is found to quench thirst, and by the immersion of the body in water, the skin will absorb sufficient to satisfy the demands of the system. The length of time that man can exist without food or drink is estimated to be about seven days. If water alone be supplied, life will last much longer; there being cases recorded where men have lived twenty days and over, without taking any solid food.
5. Amount of food required? The young and others? Those living in hot and cold climates? Habits?
5. Quantity of Food.—The quantity of food required varies greatly, according to the individual and his mode of life. The young, and others who lead active lives, or who live in the open air, require more food than the old, the inactive, or the sedentary. Those who live in cold regions require more than the inhabitants of hot climates. Habit, also, has much to do with the quantity of food required. Some habitually eat and drink more than they actually need, while a few eat less than they should.
6. Quantity of food daily? How divided? Compare with the weight of the body?
6. The average daily quantity of food and drink for a healthy man of active habits is estimated at six pounds. This amount may be divided in about the following proportions: the mineral kingdom furnishes three and one-half pounds, including water and salt; the vegetable kingdom, one and one-half pounds, including bread, vegetables, and fruits; the animal kingdom, one pound, comprising meat, eggs, butter, and the like. This quantity is about one twenty-fourth the weight of the body, as it is generally computed; the average weight of an adult man being placed at 140 pounds. A man, therefore, consumes an amount of solid and liquid nutriment every twenty-four days equal in weight to that of his body, a corresponding amount being excreted, or removed from the system in the same time.
7. How often then might the body be renewed? Why is it not? Opinion? How correct? What further is stated?
7. Renovation of the Body.—By this process, so far as weight is concerned, the body might be renewed every twenty-four days; but these pounds of food are not all real nutriment. A considerable portion of that which we eat is innutritious, and though useful in various ways, is not destined to repair the losses of the system. An opinion has prevailed that the body is renewed throughout once in seven years; how correct this may be it is not easy to decide, but probably the renovation of the body takes place in a much shorter period. Some parts are very frequently renewed, the nutritive fluids changing more or less completely, several times during the day. The muscles, and other parts in frequent exercise, change often during a year; the bones not so often, and the enamel of the teeth probably never changes after being once fully formed.
8. Habits of nations? Give the different cases.
8. Mixed Diet.—The habits of different nations in respect to diet exhibit the widest and strangest diversity. The civilized, cook their food, while savages often eat it in a raw state. Some prefer it when fresh, others allow it to remain until it has become tainted with decay. Those dwelling in the far north subsist almost wholly on animal food, while those living in hot climates have bountiful supplies of delicious fruits with which to satisfy all their bodily wants. One race subsists upon the banana, another upon the blubber of seals. In temperate climates, a diet composed partly of vegetable and partly of animal food is preferred.
9. The point to consider? Vegetable diet? Louis Cornaro? John the Baptist?
9. The important point to consider is, however, not one of origin, but whether the chemical principles (mentioned in the last chapter) enter into the composition of the diet. A purely vegetable diet may be selected which would contain all the principles necessary to sustain life. It is recorded of Louis Cornaro, a Venetian noble, that he supported himself comfortably for fifty-eight years on a daily allowance of twelve ounces of vegetable food, and about a pint of light wine. On the other hand, the food of John the Baptist, consisting of "locusts and wild honey," is an example of the sustaining power of a diet chiefly animal in its origin.
10. What has been found in our climate? Exclusive vegetable diet?
10. In our climate, those who lead active lives crave an allowance of animal food; and it has been found by experience that with it they can accomplish more work and are less subject to fatigue, than without it. Among nations where an exclusively vegetable diet is employed, indigestion is a disorder especially prevalent.
11. Necessity for change in diet? Continuous use of the same diet? Exception? Why? Too rich diet? Horses?
11. The necessity for occasionally changing or varying the diet, is seen in the fact that no single article comprises all the necessary principles of food, and that the continuous use of any one diet, whether salt or fresh, is followed by defective nutrition and disease. There is one exception to this rule: in infancy, milk alone is best calculated to support life; for then the digestive powers are incompletely developed, and the food must be presented in the simplest form possible. It should also be remembered that too rich diet is injurious, just as truly as one that is inadequate. When the food of horses is too nutritious, instinct leads them to gnaw the wood-work of their mangers.
12. Milk as a model food? Cow's milk? The constituents when separated?
12. Different Articles of Diet—Milk.—Milk is the earliest nutriment of the human race, and in the selection and arrangement of its constituents, may be regarded as a model food, no other single article being capable of sustaining life so long. Cow's milk holds casein, one of the albuminoids, about five parts in one hundred; a fatty principle, when separated, known as butter, about four parts; sugar of milk four parts; water and salts eighty-seven parts. The casein and fatty substance are far more digestible in milk, than after they have been separated from it in the form of cheese and butter.
13. Milk as a beverage? Milk sold in cities? How to detect the cheat?
13. Since milk, in itself, is so rich an article of food, the use of it as a beverage is unwise, unless the quantity of the other articles consumed be reduced at the same time. The milk sold in cities is apt to be diluted with water. The way to detect the cheat is by testing the specific gravity of the article. Good milk is about 1030; skimmed milk 1035; but milk diluted one-fifth is 1024. An instrument called the lactometer is also used, by which the amount of cream present is ascertained.
14. Composition of eggs? Yolk? How should eggs be eaten? Why? How boiled? Why?
14. Eggs.—The egg is about two-thirds water, the balance is pure albumen and fat in nearly equal proportions. The fat is in the yolk, and gives it its yellow color. Eggs contain none of the sugar-principles, and should be eaten with bread or vegetables that contain them. Soft-boiled eggs are more wholesome than those which are hard-boiled or fried, as the latter require longer time to digest.
15. Meats, whence derived? Why important? Flesh of young animals?
15. Meats.—The meats, so called, are derived from the muscular parts of various animals. They are most important articles of food for adults, inasmuch as they are richly stored with albuminoid substances, and contain more or less fat. Such food is very nourishing and easily digested if eaten when fresh,—veal and pork being exceptions. The flesh of young animals is more tender and, in general, more digestible than that of older ones. All meat is more tough immediately after the killing of the animal, but improves by being kept a certain length of time.
16. Preference of persons? Venison? Mutton? Cheese? Uncooked flesh?
16. Some persons prefer flesh that has begun to show signs of decomposition, or is unmistakably putrid. By some, venison is not considered to have its proper flavor until it is tainted. In England, people prefer mutton that is in a similar condition, just as on the continent of Europe many delight in cheese that is in a state of decomposition. In certain less civilized countries flesh is not only eaten uncooked, but in a mouldy, rotten condition. The use of such food is not always immediately injurious, but it predisposes to certain diseases, as indigestion and fevers.
17. Cold as a preserver? Meat in Russia? Beef and pork, how preserved? Salted meat as food? Scurvy?
17. Cold is one means of preserving meat from decay. In the markets of northern Russia, the frozen carcases of animals stand exposed for sale in the winter air for a considerable time, and are sawn in pieces, like sticks of wood, as the purchases are made; such meat, when thawed, being entirely fit for food. Beef and pork are preserved by salting down in brine, and in this condition may be carried on long voyages or kept for future use. Salted meat is not as nutritious as fresh, since the brine absorbs its rich juices and hardens its fibres. Long continued use of salt meats, without fresh vegetables, gives rise to the disease called scurvy, formerly very prevalent on shipboard and in prisons; but now scarcely known.
18. The antiquity of the custom of cooking food? Object of cooking? The oyster? Raw meat as an occasional food?
18. Cooking.—The preparation of food by the agency of fire is of almost universal practice, even among the rudest nations. The object of cooking is to render food more easy of digestion by softening it, to develop its flavor, and to raise its temperature more nearly to that of the body. A few articles of flesh-food are eaten uncooked in civilized lands, the oyster being an instance. Raw meat is occasionally eaten by invalids with weak digestive powers, and by men training for athletic contests.
19. Effect of boiling meat? How may the cooking be done? The proper method? Effect? Making of soup?
19. In boiling meat, the water in which it is placed tends to dissolve its nutrient juices. In fact, the cooking may be so conducted as to rob the meat of its nourishment, its tenderness, and even of its flavor. The proper method, in order to preserve or promote these qualities, is to place the meat in boiling water, which, after a few minutes, should be reduced in temperature. In this way the intense heat, at first, coagulates the exterior layers of albumen, and imprisons the delicate juices; after that, moderate heat best softens it throughout. When soup is to be made, an opposite course should be pursued; for then the object is to extract the juices and reject the fibre. Meat, for such purpose, should be cut in small pieces and put into cold water, which should then be gradually raised to boiling heat.
| PAGE | |
| 1. What is understood by the term food? | [53] |
| 2. What can you state in relation to the source of food? | [53] |
| 3. What discriminations and selections are necessary? | [53], 54 |
| 4. How can you tell the organic from the inorganic substances? | [54] |
| 5. What relative position does water hold as an article of food? | [54] |
| 6. In what parts of the body is water found? | [54], [55] |
| 7. In what articles that we eat is it found? | [55] |
| 8. If you were required to go without water or solid food for a number of days, which would you prefer to have, and why? | [55] |
| 9. What can you state of the importance of salt as an article of food? | [55], [56] |
| 10. How abundant is salt, and how does it find its way into the human system? | [55], [56] |
| 11. What can you state of the importance of lime in the body? | [56] |
| 12. What, of the importance of iron? | [56], [57] |
| 13. What further is stated of other inorganic substances? | [57] |
| 14. What in relation to organic substances? | [57] |
| 15. What can you state in relation to the albuminoids? | [57], [58] |
| 16. What, in relation to albumen? | [58] |
| 17. What, in relation to casein? | [58], [59] |
| 18. In relation to the fats or oils, and how generally consumed? | [59], [60] |
| 19. What do we understand by the sugars or saccharine substances? | [60] |
| 20. State what you can of sugar—its origin and various qualities. | [60], [61] |
| 21. Of starch—its varieties and qualities. | [61] |
| 22. Of the abundance of starch, and its importance as a food principle. | [61] |
| 23. What is stated in relation to stimulating substances? | [62] |
| 24. Of the necessity for regulation in diet? | [62], [63] |