"No rest this throbbing slave may ask, Forever quivering o'er his task, While far and wide a crimson jet Leaps forth to fill the woven net, Which in unnumber'd crossing tides The flood of burning life divides, Then, kindling each decaying part, Creeps back to find the throbbing heart."
HOLMES.
ANALYSIS OF THE CIRCULATION
" 1. Its Composition. " 1. THE BLOOD " 2. Its Uses. " " 3. Transfusion. " "4. Coagulation " " " 1. Description. " " 2. Movements. " " 3. Auricles and Ventricles. " " " " 1. The " " a. Need of. " " Heart." " b. Tricuspid and " " " " Bicuspid. " " " 4. The " c. The Strengthen- " " " Valves. " ing of the " " " " Valves. " " " " d. Semilunar " " " " Valves. " " _ " 2. ORGANS OF THE " 2. The " 1. Description. " CIRCULATION " Arteries " 2. The Arterial System. " " "_3. The Pulse. " " _ " " 3. The " 1. General Description. " " Veins "_2. Valves. " " _ " " 4. The " 1. Description. " " Capilla-" 2. Use. " "_ ries "_3. Under the Microscope. " _ " " 1. The Lesser. " 3. THE CIRCULATION." 2. The Greater. " "3. The Velocity of the Blood. " " 4. THE HEAT OF THE " 1. Distribution. " BODY. "2. Regulation. " " 5. LIFE BY DEATH. " " 6. CHANGE OF OUR BODIES. " " 7. THE THREE VITAL ORGANS. " " 8. WONDERS OF THE HEART. " " " 1. Description " 9. THE LYMPHATIC " 2. The Glands. " CIRCULATION. " 3. The Lymph. " "4. The Office of the Lymphatics. " " " 1. Congestion. " " 2. Inflammation. " " 3. Bleeding. " 10. DISEASES. " 4. Scrofula. " " 5. A Cold. " "6. Catarrh. " " " 1. Effect of Alcohol upon the Circulation. " 11. ALCOHOLIC " 2. Effect of Alcohol upon the Heart. " DRINKS AND " 3. Effect of Alcohol upon the Membrane. "_ NARCOTICS. " 4. Effect of Alcohol upon the Blood. "_5. Effect of Alcohol upon the Lungs.
THE CIRCULATION.
THE ORGANS OF THE CIRCULATION are the heart, the arteries, the veins, and the capillaries.
FIG. 35.
[Illustration: A, corpuscles of human blood, highly magnified; B, corpuscles in the blood of an animal (a non mammal).]
THE BLOOD is the liquid by means of which the circulation is effected. It permeates every part of the body, except the cuticle, nails, hair, etc. The average quantity in each person is about eighteen pounds. [Footnote: It is difficult to estimate the exact amount, and therefore authorities disagree. Foster places it at about one thirteenth of the body weight.] It is composed of a thin, colorless liquid, the plasma, filled with red disks or cells, [Footnote: There is also one white globular cell to every three or four hundred red ones. The blood is no more red than the water of a stream would be if you were to fill it with little red fishes. Suppose the fishes to be very, very small—as small as a grain of sand— and closely crowded together through the whole depth of the stream; the water would look quite red, would it not? And this is the way in which, blood looks red—only observe one thing; a grain of sand is a mountain in comparison with the little red fishes in the blood. If I were to tell you they measured about 1/3500 of an inch in diameter, you would not be much wiser; so I prefer saying (by way of giving you a more perfect idea of their minuteness) that there would be about a million in such a drop of blood as would hang on the point of a needle. I say so on the authority of a scientific microscopist—M. Bouillet. Not that he has ever counted them, as you may suppose, any more than I have done; but this is as near an approach as can be made by calculation to the size of 1/3500 part of an inch in diameter.—JEAN MACE.] so small that about three thousand five hundred placed side by side would measure only an inch, and it would take sixteen thousand laid flatwise upon one another to make a column of that height. Under the microscope, they are found to be rounded at the edge and concave on both sides. [Footnote: By pricking the end of the finger with a needle, we can obtain a drop for examination. Place it on the slide, cover with a glass, and put it at once under the microscope. The red disks will be seen to group themselves in rows, while the white disks will seem to draw apart, and to be constantly changing their form. After a gradual evaporation, the crystals (Fig. 36) may be seen. In animals, they have various, though distinctive forms.] They have a tendency to collect in piles like rolls of coin. The size and shape vary in the blood of different animals. [Footnote: Authorities differ greatly in their estimate of the size of the disks (corpuscles) in human blood. The fact is that the size varies in different persons, probably also in the same individual. Many of the best microscopists therefore hesitate to state whether a particular specimen of blood belonged to a human being or to an animal. Others claim that they can distinguish with accuracy. Evidently, the question is one of great uncertainty. The following statement of the size of the cells in different animals is taken from Gulliver's tables: Cat, 1/4404 of an inch in diameter; whale, 1/3100; mouse, 1/3614; hog, 1/4230; camel, 1/3123; sheep, 1/3352; horse, 1/4800; Virginia deer, 1/5038; dog- faced baboon, 1/4861; brown baboon, 1/3493; red monkey, 1/3396; black monkey, 1/3530.] Disks are continually forming in the blood, and are constantly dying—twenty million at every breath.—DRAPER.
The plasma also contains fibrin, [Footnote: it is usual to say that fibrin is contained in the blood. It probably does not exist as such, but there are present in the blood certain substances known as paraglobulin and fibrinogen, which by the action of a third substance, fibrin ferment under certain circumstances, form fibrin and so cause coagulation. The exact nature of the process by which fibrin is produced by these three factors is not understood—See Foster's Text Book of Physiology, p 22.] albumin—which is found nearly pure in the white of an egg—and various mineral substances, as iron, [Footnote: Enough iron has been found in the ashes of a burned body to form a mourning ring.] lime, magnesia, phosphorus, potash, etc.
FIG. 36.
[Illustration: Blood Crystals]
USES OF THE BLOOD.—The blood has been called "liquid flesh"; but it is more than that, since it contains the materials for making every organ. The plasma is rich in mineral matter for the bones, and in albumen for the muscles. The red disks are the air cells of the blood. They contain the oxygen so essential to every operation of life. Wherever there is work to be done or repairs to be made, there the oxygen is needed. It stimulates to action, and tears down all that is worn out. In this process, it combines with and actually burns out parts of the muscles and other tissues, as wood is burned in the stove. [Footnote: For the sake of simplicity, perhaps to conceal our own ignorance, we call this process "burning." The simile of a fire is good so far as it goes. But as to the real nature of the change which the physiologist briefly terms "oxidation," we know nothing. This much only can be asserted positively. A stream of oxygen is carried by the blood to the muscles (in fact to every tissue in the body), while, from the muscles the blood carries away a stream of carbonic acid and water. But what takes place in the muscles, when and what chemical change occurs, no one can tell. We see the first and the last stage. We know that contraction of the muscles somehow comes about, oxygen disappears, carbonic acid appears, energy is released, and force is exhibited as motion, heat, and electricity. But the intermediate step is hidden.
There are certain theories advanced, however, that are worth considering. Some physiologists hold that the muscle has the power of taking up the oxygen from the hemoglobin (a body that comprises ninety per cent of the red corpuscles when dried, and is the oxygen carrier of the blood), and fixing it, as well as the raw material (food) furnished by the blood, thus forming a true contractile substance. The breaking down or decomposition of this contractile substance in the muscle, sets free its potential energy. The process is gentle so long as the muscle is at rest, but becomes excessive and violent when contraction occurs. (See "Foster's Physiology," p. 118.) It is also believed by some that the chemical change in the muscle partakes of a fermentive character; that, under the influence of the proper ferments, the substances break up into other and simpler products, thus setting free heat and force; and that this chemical change is followed by a secondary oxidation by the oxygen in the arterial blood, thereby forming carbonic acid and water, as in all putrefactive processes. But these and other views are not as yet fully understood; while they utterly fail to tell us how a collection of simple cells, filled merely with a semifluid mass of matter, can contract and set free muscular power. The commonness of this act hides from us its wonderful nature. But here, hidden in the cell—Nature's tiny laboratory—lies the mystery of life. Before its closed door we ponder in vain, confessing the unskillfulness of our labor, and fearing all the while lest the Secret of the Cell will always elude our search.] The blood, now foul with the burned matter, the refuse of this fire, is caught up by the circulation, and whirled back to the lungs, where it is purified, and again sent bounding on its way.
There are then two different kinds of the blood in the body: the red or arterial, and the dark or venous.
TRANSFUSION.—As the blood is really the "vital fluid" it would seem that feeble persons might be restored to vigor by infusing healthy blood into their veins. This hypothesis, so valuable in its possible results in prolonging human life, has been carefully tested. Animals which have ceased to breathe have thus had their vitality recalled. In the seventeenth century the theory became a subject of special investigation. A maniac was restored to reason by the blood of a calf, and the most extravagant hopes were entertained. But many fatal accidents occurring, experiments upon human beings were forbidden by law, and transfusion soon fell into disuse. It has, however, been successfully practiced in several cases within the last few years, and is a method still in repute for saving lives.
COAGULATION.—When blood is exposed to the air, it coagulates. This is caused by the solidifying of the fibrin, which entangling the disks, forms the "clot." The remaining clear, yellow liquid is the serum. The value of this peculiar property of the blood can hardly be overestimated. The coagulation soon checks all ordinary cases of bleeding. [Footnote: In the case of the lower animals, which have no means of stopping hemorrhages as we have, the coagulation is generally still more rapid. In some species of birds it takes place almost instantaneously.] When a wound is made, and bleeding commences, the fibrin forms a temporary plug, as it were, which is absorbed when the healing process is finished. Thus we see how a Divine foresight has provided not only for the ordinary wants of the body, but also for the accidents to which it is liable. [Footnote: The fibrin is not an essential ingredient of the blood. All the functions of life are regularly performed in people whose blood lacks fibrin; and, in cases of transfusion, where blood deprived of its fibrin was used, the vivifying influence seemed to be the same. Its office, therefore, must mainly be to stanch any hemorrhage which may occur.—FLINT.]
FIG. 37.
[Illustration: The Heart. A, the right ventricle; B, the left ventricle; C, the right auricle; D, the left auricle.]
THE HEART is the engine which propels the blood. It is a hollow, pear- shaped muscle, about the size of the fist. It hangs, point downward, just to the left of the center of the chest. (See Fig. 31.) It is inclosed in a loose sac of serous membrane, [Footnote: The mucous membrane lines the open cavities of the body; the serous, the closed. The pericardium is a sac composed of two layers—a fibrous membrane on the outside, and a serous one on the inside. The latter covers the external surface of the heart, and is reflected back upon itself in order to form, like all the membranes of this nature, a sac without an opening. The heart is thus covered by the pericardial sac, but not contained inside its cavity. A correct idea may be formed of the disposition of the pericardium around the heart by recalling a very common and very convenient, though now discarded headdress, the cotton nightcap. The pericardium incloses the heart exactly as this cap covered the heads of our forefathers.— Wonders of the Human Body.] called the pericardium (peri, about; and kardia, the heart). This secretes a lubricating fluid, and is smooth as satin.
THE MOVEMENTS OF THE HEART consist of an alternate contraction and expansion. The former is called the sys'-to-le, and the latter the di-as'-to-le. During the diastole, the blood flows into the heart, to be expelled by the systole. The alternation of these movements constitutes the beating of the heart which we hear so distinctly between the fifth and sixth ribs. [Footnote: Two sounds are heard if we put our ear over the heart,—the first and longer as the blood is leading the organ, the second as it falls into the pockets of the two arteries, and the valves then striking together cause it. The first sound is mainly the noise made by the muscular tissue. During the first, the two ventricles contract; during the second the two auricles do so. The hand may feel the heart striking the ribs as it contracts,—a feeling called the impulse, or, if quicker and stronger than usual, palpitation. This is not always a sign of disease, but in hypochondriacs is often an effect of the mind on the nerves of the heart.—MAPOTHER]
FIG. 38.
[Illustration: Chambers of the Heart A, right ventricle; B, left ventricle, C, right auricle, D, left auricle, E, tricuspid valve, F, bicuspid valve; G, semilunar valves, H, valve of the aorta; I, inferior vena cava, K, superior vena cava, L, L, pulmonary veins.]
THE AURICLES AND VENTRICLES—The heart is divided into four chambers. In an adult, each holds about a wineglassful. The upper ones, from appendages on the outside resembling the ears of a dog, are called auricles (aures, ears). are termed ventricles. The auricle and ventricle on each side communicate with each other, but the right and left halves of the heart are entirely distinct, and perform different offices. The left side propels the red blood; and the right, the dark. The auricles are merely reservoirs to receive the blood (the left auricle, as it filters in bright and pure from the lungs; the right, as it returns dark and foul from the tour of the body), and to furnish it to the ventricles as they need. Their work being so light, their walls are comparatively thin and weak. On the other hand, the ventricles force the blood (the left, to all parts of the body; the right, to the lungs), and are, therefore, made very strong. As the left ventricle drives the blood so much farther than the right, it is correspondingly thicker and stronger.
NEED OF VALVES IN THE HEART.—As the auricles do not need to contract with much force simply to empty their contents into the ventricles below them, there is no demand for any special contrivance to prevent the blood from setting back the wrong way. Indeed, it would naturally run down into the ventricle, which is at that moment open to receive it. But, when the strong ventricles contract, especially the left one, which must drive the blood to the extremities, some arrangement is necessary to prevent it from returning into the auricle. Besides, when they expand, the "suction power" would tend to draw back again from the arteries all the blood just forced out. This difficulty is obviated by means of little doors, or valves, which will not let it go the wrong way. [Footnote: The heart of an ox or a sheep may be used to show the chambers and valves. The aorta should be cut as far as possible from the heart, and then by pumping in water the perfection of these valves will be finely exhibited. Cutting the heart across near the middle will show the greater thickness of the left ventricle.]
THE TRICUSPID AND BICUSPID VALVES.—At the opening into the right ventricle, is a valve consisting of three folds or flaps of membrane, whence it is called the tricuspid valve (tri, three; and cuspides, points), and in the left ventricle, one containing two flaps, and named the bicuspid valve. These hang so loosely as to oppose no resistance to the passage of the blood into the ventricles; but, if any attempts to go the other way, it gets between the flaps and the walls of the heart, and, driving them outward, closes the orifice.
FIG. 39.
[Illustration: Diagram showing the peculiar Fibrous Structure of the Heart and the Shape of the Valves. A, tricuspid valve, B, bicuspid valve; C, semilunar valves of the aorta; D, semilunar valves of the pulmonary artery.]
THESE FLAPS ARE STRENGTHENED like sails by slender cords, which prevent their being pressed back through the opening. If the cords were attached directly to the walls of the heart, they would be loosened in the systole, and so become useless when most needed. They are, therefore, fastened to little muscular pillars projecting from the sides of the ventricle; when that contracts, the pillars contract also, and thus the cords are held tight.
THE SEMILUNAR VALVES.—In the passages outward from the ventricles, are valves, called from their peculiar half-moon shape semilunar valves (semi, half; Luna, Moon). Each consists of three little pocket-shaped folds of membrane, with their openings in the direction which the blood is to take. When it sets back, they fill, and, swelling out, close the passage (Fig. 40).
THE ARTERIES [Footnote: Aer, air; and tereo, I contain—so named because after death they contain air only, and hence the ancients supposed them to be air tubes leading through the body.] are the tube-like canals which convey the blood from the heart. They carry the red blood (see note, p. 119). They are composed of an elastic tissue, which yields at every throb of the heart, and then slowly contracting again, keeps up the motion of the blood until the next systole. The elasticity of the arteries acts like the air chamber of a fire engine, which converts the intermittent jerks of the brakes or pump into the steady stream of the hose nozzle.
The arteries sometimes communicate by means of branches or by meshes of loops, so that if the blood be blocked in one, it can pass round through another, and so get by the obstacle. [Footnote: This occurs especially about the joints, where it serves to maintain the circulation during the bending of a limb, or when the main artery is obstructed by disease or injury, or has been tied by the surgeon. In the last case, the small adjacent arteries gradually enlarge, and form what is called a collateral circulation.] When an artery penetrates a muscle, it is often protected by a sheath or by fibrous rings, which prevent its being pulled out of place or compressed by the play of the muscles.
The arteries are generally located as far as possible beneath the surface, out of harm's way, and hence are found closely hugging the bones or creeping through safe passages provided for them. They are generally nearly straight, and take the shortest routes to the parts which they are to supply with blood.
THE ARTERIAL SYSTEM starts from the left ventricle by a single trunk—the aorta—which, after giving off branches to the head, sweeps back of the chest with a bold curve—the arch of the aorta (c, Fig. 34)—and thence runs downward (f), dividing and subdividing, like a tree, into numberless branches, which, at last, penetrate every nook and corner of the body.
THE PULSE.—At the wrist (k, radial artery) and on the temple (temporal artery) we can feel the expansion of the artery by each little wave of blood set in motion by the contraction of the heart. In health, there are about seventy-two [Footnote: This number varies much with age, sex, and individuals. Napoleon's pulse is said to have been only forty, while it is not infrequent to find a healthy pulse at one hundred or over. In general, the pulse is quicker in children and in old people than in the middle-aged; in short persons than in tall; in women than in men. Shame makes the heart send more blood to the blushing cheek, and fear almost stops it. The will can not check the heart. There is said, however, to have been a notable exception to this in the case of one Colonel Townsend, of Dublin, who, after having succeeded several times in stopping the pulsation, at last lost his life in the act.] pulsations per minute. They increase with excitement or inflammation, weaken with loss of vigor, and are modified by nearly every disease. The physician, therefore, finds the pulse a good index of the state of the system and the character of the disorder. (See p. 314.)
THE VEINS are the tube-like canals which convey the blood to the heart. [Footnote: There is one exception to the general course of the veins. The portal vein carries the blood from the digestive organs to the liver, where it is acted upon, thence poured into the ascending vena cava, and goes back to the heart.] They carry the dark or venous blood (note, p. 119). As they do not receive the direct impulse of the heart, their walls are made much thinner and less elastic than those of the arteries. At first small, they increase in size and diminish in number as they gradually pour into one another, like tiny rills collecting to form two rivers, the vena cava ascending and the vena cava descending (l, m, Fig. 34), which empty into the right auricle.
Some of the veins creep along under the skin, where they can be seen, as in the back of the hand; while others accompany the arteries, some of which have two or more of these companions.
VALVES similar in construction to those already described (the semilunar valves of the heart, page 114) are placed at convenient intervals, in order to guide the blood in its course, and prevent its setting backward. [Footnote: Too much standing, or tight elastics, often cause the veins in the leg to swell, so that the valves can not work; the veins then become varicose, or permanently enlarged, and, if they burst, the bleeding may be profuse and even dangerous. Raising the leg and pressing the finger on the bleeding spot will stay it. Walking does not encourage this disease, for the active muscles force on the venous blood. Clerks who are subject to varicose veins should have seats behind the counters where they may rest when not actually employed. A deep breath helps the flow in the veins, and a wound may suck in air with fatal effect. A maimed horse is most mercifully killed by blowing a bubble of air into the veins of his neck. As the deep-sea pressure would burst valves, the whale has none; hence a small wound by the harpoon causes him to bleed to death.— MAPOTHER.] We can easily examine the working of these valves. On baring the arm, blue veins may be seen running along the arm toward the hand. Their diameter is tolerably even, and they gradually decrease in size. If now the finger be pressed on the upper part of one of these veins, and then passed downward so as to drive its blood backward, swellings like little knots will make their appearance. Each of these marks the location of a valve, which is closed by the blood we push before our finger. Remove the pressure, and the valve will swing open, the blood set forward, and the vein collapse to its former size.
FIG. 40.
[Illustration: Valves of the Veins.]
THE CAPILLARIES (capillus, a hair) form a fine network of tubes, connecting the ends of the arteries with the veins. They blend, however, with the extremities of these two systems, so that it is not easy to tell just where an artery ends and a vein begins. So closely are they placed, that we can not prick the flesh with a needle without injuring, perhaps, hundreds of them. The air cells of the blood deposit there their oxygen, and receive carbonic acid, while in the delicate capillaries of the lungs [Footnote: The capillary tubes are there so fine that the disks of the blood have to go one by one, and are sadly squeezed at that. However, their elasticity enables them to resume their old shape as soon as they have escaped from this labyrinth.] they give up their load of carbonic acid in exchange for oxygen.
FIG. 41.
[Illustration: Circulation of the Blood in the Web of a Frog's Foot, highly magnified. A, an artery; B, capillaries crowded with disks, owing to a rupture just above, where the disks are jammed into an adjacent mesh; C, a deeper vein; the black spots are pigment cells.]
If, by means of a microscope, we examine the transparent web of a frog's foot, we can trace the route of the blood. [Footnote: With small splints and twine, a frog's foot can be easily stretched and tied so that the transparent web can be placed on the table of the microscope.] It is an experiment of wonderful interest. The crimson stream, propelled by the heart, rushes through the arteries, until it reaches the intricate meshes of the capillaries. Here it breaks into a thousand tiny rills. We can see the disks winding in single file through the devious passages, darting hither and thither, now pausing, swaying to and fro with an uncertain motion, and anon dashing ahead, until, at last, gathered in the veins, the blood sets steadily back on its return to the heart.
THE CIRCULATION [Footnote: The circulation of the blood was discovered by Harvey in 1619. For several years, he did not dare to publish his belief. When it became known, he was bitterly persecuted, and his practice as a physician greatly decreased in consequence. He lived, however, to see his theory universally adopted, and his name honored. Harvey is said to have declared that no man over forty years of age accepted his views.] consists of two parts—the lesser, and the greater.
FIG. 42.
[Illustration: Diagram illustrating the Circulation of the Blood.— MARSHALL. A, vena cava descending (superior); Z, vena cava ascending (inferior); C, right auricle; D, right ventricle; E, pulmonary artery; F P, lungs and pulmonary veins; G, left auricle; H, left ventricle; I, K, aorta.]
1. The Lesser Circulation.—The dark blood from the veins collects in the right auricle, and, going through the tricuspid valve, empties into the right ventricle. Thence it is driven past the semilunar valves, through the pulmonary artery, to the lungs. After circulating through the fine capillaries of the air cells contained in the lungs, it is returned, bright and red, through the four pulmonary veins, [Footnote: It is noticeable that the pulmonary set of veins circulates red blood, and the pulmonary set of arteries circulates dark blood. Both are connected with the lungs.] to the left auricle.
2. The Greater Circulation.—From the left auricle, the blood is forced past the bicuspid valve to the left ventricle; thence it is driven through the semilunar valves into the great aorta, the main trunk of the arterial system. Passing through the arteries, capillaries, and veins, it returns through the venÆ cavÆ, ascending and descending, gathers again in the right auricle, and so completes the "grand round" of the body. Both these circulations are going on constantly, as the two auricles contract, and the two ventricles expand simultaneously, and vice versa.
THE VELOCITY OF THE BLOOD varies so much in different parts of the body, and is influenced by so many circumstances, that it can not be calculated with any degree of accuracy. It has been estimated that a portion of the blood will make the tour of the body in about twenty-three seconds (FLINT), and that the entire mass passes through the heart in from one to two minutes. [Footnote: The total amount of blood in an adult of average weight is about eighteen pounds. Dividing this by five ounces, the quantity discharged by the left ventricle at each systole, gives fifty- eight pulsations as the number necessary to transmit all the blood in the body. This, however, is an extremely unreliable basis of calculation, as the rapidity of the blood is itself so variable. Chauvreau has shown by experiments with his instrument that, corresponding to the first dilation of the vessels, the blood moves with immense rapidity; following this, the current suddenly becomes nearly arrested; this is succeeded by a second acceleration in the current, not quite so rapid as the first; and after this there is a gradual decline in the rapidity to the time of the next pulsation.] (See p. 314.)
DISTRIBUTION AND REGULATION OF THE HEAT OF THE BODY.—1. Distribution.—The natural temperature is not far from 98°. [Footnote: The average temperature is, however, easily departed from. Through some trivial cause the cooling agencies may be interfered with, and then, the heating processes getting the superiority, a high temperature or fever comes on. Or the reverse may ensue. In Asiatic cholera, the constitution of the blood is so changed that its disks can no longer carry oxygen into the system, the heat-making processes are put a stop to, and, the temperature declining, the body becomes of a marble coldness, characteristic of that terrible disease.—DRAPER.] This is maintained, as we have already seen, by the action of the oxygen within us. Each capillary tube is a tiny stove, where oxygen is combining with the tissues of the body (see note, p. 107). Every contraction of a muscle develops heat, the latent heat being set free by the breaking up of the tissue. The warmth so produced is distributed by the circulation of the blood. Thus the arteries, veins, and capillaries form a series of hot- water pipes, through which the heated liquid is forced by a pump—the heart—while the heat is kept up, not by a central furnace and boiler, but by a multitude of little fires placed here and there along its course.
2. Regulation.—The temperature of the body is regulated by means of the pores of the skin and the mucous membrane in the air passages. When the system becomes too warm, the blood vessels on the surface expand, the blood fills them, the fluid exudes into the perspiratory glands, pours out upon the exterior, and by evaporation cools the body. [Footnote: Just as water sprinkled on the floor cools a room.—Popular Physics, p. 255.] When the temperature of the body is too low, the vessels contract, less blood goes to the surface, the perspiration decreases, and the loss of heat by evaporation diminishes. [Footnote: Thus one is enabled to go into an oven where bread is baking, or into the arctic regions where the mountains are snow and the rivers ice. Even by these extremes the temperature of the blood will be but slightly affected. In the one case, the flood gates of perspiration will be opened and the superfluous heat expended in turning the water to vapor; and, in the other, they will be tightly closed and all the heat retained.]
LIFE BY DEATH.—The body is being incessantly corroded, and portions borne away by the tireless oxygen. The scales of the epidermis are constantly falling off and being replaced by secretion from the cutis. The disks of the blood die, and new ones spring into being. On the continuance of this interchange depend our health and vigor. Every act is a destructive one. Not a bend of the finger, not a wink of the eye, not a thought of the brain but is at some expense of the machine itself. Every process of life is thus a process of death. The more rapidly this change goes on, and fresh, vigorous tissue takes the place of the old, the more elasticity and strength we possess.
CHANGE OF OUR BODIES.—There is a belief that our bodies change once in seven years. From the nature of the case, the rate must vary with the labor we perform; the organs most used altering oftenest. Probably the parts of the body in incessant employment are entirely reorganized many times within a single year. [Footnote: To use a homely simile, our bodies are like the Irishman's knife, which, after having had several new blades, and at least one new handle, was yet the same old knife.]
THE THREE VITAL ORGANS.—Death is produced by the stoppage of the action of any one of the three organs—the heart, the lungs, or the brain. They have, therefore, been termed the "Tripod of Life." Really, however, as Huxley has remarked, "Life has but two legs to stand upon." If respiration and circulation be kept up artificially, the removal of the brain will not produce death. [Footnote: When death really does take place, i. e., when the vital organs are stopped, it is noticeable that the tissues do not die for some time thereafter. If suitable stimulants be applied, as the galvanic battery, transfusion of blood, etc., the muscles may be made to contract, and many of the phenomena of life be exhibited. Dr. Brown- Sequard thus produced muscular action in the hand of a criminal, fourteen hours after his execution.]
WONDERS OF THE HEART.—The ancients thought the heart to be the seat of love. There were located the purity and goodness as well as the evil passions of the soul. [Footnote: Our common words, hearty, large-hearted, courage (cor, the heart), are remains of this fanciful theory.] Modern science has found the seat of the mental powers to be in the brain. But while it has thus robbed the heart of its romance, it has revealed wonders which eclipse all the mysteries of the past. This marvelous little engine throbs on continually at the rate of one hundred thousand beats per day, forty millions per year, often three billions without a single stop. It is the most powerful of machines. "Its daily work is equal to one third that of all the muscles. If it should expend its entire force in lifting its own weight vertically, it would rise twenty thousand feet in an hour." [Footnote: "The greatest exploit ever accomplished by a locomotive, was to lift itself through less than one eighth of that distance." Vast and constant as is this process, so perfect is the machinery, that there are persons who do not even know where the heart lies until disease or accident reveals its location.] Its vitality is amazing. The most tireless of organs while life exists, it is one of the last to yield when life expires. So long as a flutter lingers at the heart, we know the spark of being is not quite extinguished, and there is hope of restoration. During a life such as we sometimes see, it has propelled half a million tons of blood, yet repaired itself as it has wasted, during its patient, unfaltering labor. The play of its valves and the rhythm of its throb have never failed until, at the command of the great Master Workman, the "wheels of life have stood still." [Footnote: Our brains are seventy-five- year clocks. The Angel of Life winds them up once for all, then closes the case, and gives the key into the hand of the Angel of the Resurrection. Ticktack! Ticktack! go the wheels of thought; our will can not stop them, they can not stop themselves; sleep can not stop them; madness only makes them go faster; death alone can break into the case, and, seizing the ever-swinging pendulum which we call the heart, silence at last the clicking of the terrible escapement we have carried so long beneath our wrinkled foreheads.—HOLMES.]
FIG. 43.
[Illustration: Lymphatics of the Head and Neck, showing the Glands, and, B, the thoracic duct as it empties into the left innominate vein at the junction of the left jugular and subclavian veins.]
THE LYMPHATIC CIRCULATION is intimately connected with that of the blood. It is, however, more delicate in its organization, and less thoroughly understood. Nearly every part of the body is permeated by a second series of capillaries, closely interlaced with the blood capillaries already described, and termed the Lymphatic system. The larger number converge into the thoracic duct—a small tube, about the size of a goose quill, which empties into the great veins of the neck (Fig. 43). Along their course the lymphatics frequently pass through glands,—hard, pinkish bodies of all sizes, from that of a hemp seed to an almond. These glands are often enlarged by disease, and then are easily felt.
The Lymph, which circulates through the lymphatics like blood through the veins, is a thin, colorless liquid, very like the serum. This fluid, probably in great measure an overflow from the blood vessels, is gathered up by the lymphatics, undergoes in the glands some process of preparation not well understood, and is then returned to the circulation.
FIG. 44.
[Illustration: Lymphatics in the Leg, with Glands at the Hip.]
OFFICE OF THE LYMPHATICS.—It is thought that portions of the waste matter of the body capable of further use are thus, by a wise economy, retained and elaborated in the system.
The lacteals, a class of lymphatics which will be described under Digestion (p. 166), aid in taking up the food; after a meal they become milk white. In the lungs, the lymphatics are abundant; sometimes absorbing the poison of disease, and diffusing it through the system. [Footnote: Persons have thus been poisoned by tiny particles of arsenic which evaporate from green wall paper, and float in the air.]
The lymphatics of the skin we have already spoken of as producing the phenomena of absorption, [Footnote: Pain is often relieved by injecting under the cuticle a solution of morphine, which is taken up by the absorbents, and so carried through the system.] Nature in her effort to heal a cut deposits an excess of matter to fill up the breach. Soon, the lymphatics go to work and remove the surplus material to other parts of the body.
Animals that hibernate are supported during the winter by the fat which their absorbents carry into the circulation from the extra supply they have laid up during the summer. In famine or in sickness, a man unconsciously consumes his own flesh.
DISEASES, ETC.—l. Congestion is an unnatural accumulation of blood in any part of the body. The excess is indicated by the redness. If we put our feet in hot water, the capillaries will expand by the heat, and the blood will set that way to fill them. The red nose and purplish face of the drunkard show a congestion of the capillaries. Those vessels have lost their power of contraction, and so are permanently increased in size and filled with blood. Blushing is a temporary congestion. The capillaries being expanded only for an instant by the nervous excitement, contract again and expel the blood. [Footnote: Blushing is a purely local modification of the circulation of this kind, and it will be instructive to consider how a blush is brought about. An emotion—sometimes pleasurable, sometimes painful—takes possession of the mind; thereupon a hot flush is felt, the skin grows red, and according to the intensity of the emotion these changes are confined to the cheeks only, or extend to the "roots of the hair," or "all over." What is the cause of these changes? The blood is a red and a hot fluid; the skin reddens and grows hot, because its vessels contain an increased quantity of this red and hot fluid; and its vessels contain more, because the small arteries suddenly dilate, the natural moderate contraction of their muscles being superseded by a state of relaxation. In other words, the action of the nerves which cause this muscular contraction is suspended. On the other hand, in many people, extreme terror causes the skin to grow cold, and the face to appear pale and pinched. Under these circumstances, in fact, the supply of blood to the skin is greatly diminished, in consequence of an excessive stimulation of the nerves of the small arteries, which causes them to contract and so to cut off the supply of blood more or less completely.— Huxley's Physiology.]
2. Inflammation means simply a burning. If there is irritation or an injury at any spot, the blood sets thither and reddens it. This extra supply, both by its presence and the friction of the swiftly moving currents, produces heat. The pressure of the distended vessels upon the nerves frets them, and produces pain. The swelling stretches the walls of the blood vessels, and the serum or lymph oozes through. The four characteristics of an inflammation are redness, heat, pain, and swelling.
3. Bleeding, if from an artery, will be of red blood, and will come in jets; [Footnote: The elasticity of the arteries (p. 114) is a physical property, as may easily be shown by removing one from a dead body. If they were rigid and unyielding, a considerable portion of the heart's force would be uselessly expended against their walls. Their expansion is a passive state, and depends on the pressure of the blood within them; but their vital contractility is an active property.—The intermittent movement of the blood through the arteries is strikingly shown in the manner in which they bleed when wounded. When an artery is cut across, the blood spurts out with great force to a distance of several feet, but the flow is not continuous. It escapes in a series of jets, the long, slender scarlet stream rising and falling with each beat of the heart, and this pulsation of the blood stream tells at once that it comes from a wounded artery. But as the blood traverses these elastic tubes, the abruptness of the heart's stroke becomes gradually broken and the current equalized, so that the greater the distance from the heart the less obvious is the pulsation, until at length in the capillaries the rate of the stream becomes uniform.] if from the veins, it will be of dark blood, and will flow in a steady stream. If only a small vessel be severed, it may be checked by a piece of cloth held or bound firmly upon the wound. If a large trunk be cut, especially in a limb, make a knot in a handkerchief and tie it loosely about the limb; then, placing the knot on the limb, with a short stick twist the handkerchief tightly enough to stop the flow. If you have a piece of cloth to use as a pad, the knot will be unnecessary. If it be an artery that is cut, the pressure should be applied between the wound and the heart; if a vein, beyond the wound. If you are alone, and are severely wounded, or in an emergency, like a railroad accident, use the remedy which has saved many a life upon the battlefield—bind or hold a handful of dry earth upon the wound, elevate the part, and await surgical assistance.
4. Scrofula is generally inherited. It is a disease affecting the lymphatic glands, most commonly those of the neck, forming "kernels," as they are called. It is, however, liable to attack any organ. Persons inheriting this disease can hope to ward off its insidious approaches only by the utmost care in diet and exercise; by the use of pure air and warm clothing, and by avoiding late hours and undue stimulus of all kinds. Probably the most fatal and common excitants of the latent seeds of scrofula are insufficient or improper food, and want of ventilation.
5. A COLD.—We put on a thinner dress than usual, or, when heated, sit in a cool place. The skin is chilled, and the perspiration checked. The blood, no longer cleansed and reduced in volume by the drainage through the pores, sets to the lungs for purification. That organ is oppressed, breathing becomes difficult, and the extra mucus secreted by the irritated surface of the membrane is thrown off by coughing. The mucous membrane of the nasal chamber sympathizes with the difficulty, and we have "a cold in the head," or a catarrh. In general, the excess of blood seeks the weakest point, and develops there any latent disease [Footnote: A party go out for a walk and are caught in a rain, or, coming home heated from some close assembly, throw off their coats to enjoy the deliciously cool breeze. The next day, one has a fever, another a slight headache, another pleurisy, another pneumonia, another rheumatism, while some of the number escape without any ill feeling whatever. The last had vital force sufficient to withstand the disturbance, but in the others there were various weak points, and to these the excess of blood has gone, producing congestion.] Where one person has been killed in battle, thousands have died of colds.
To restore the equipoise must be the object of all treatment. We put the feet in hot water and they soon become red and gorged with the blood which is thus called from the congested organs. Hot footbaths have saved multitudes of lives. It is well in case of a sudden cold to go immediately to bed, and with hot drinks and extra clothing open the pores, and induce free perspiration. This calls the blood to the surface, and, by equalizing and diminishing the volume of the circulation, affords relief. [Footnote: Severe colds may often be relieved in their first stages by using lemons freely during the day, and taking at night fifteen or twenty grains of sodium bromide. Great care, however, should be observed in employing the latter remedy, except under the advice of a physician.]
6. Catarrh commonly manifests itself by the symptoms known as those of a "cold in the head," and is produced by the same causes. It is an inflammation of the mucous membrane lining the nasal and bronchial passages. One going out from the hot dry air of a furnace-heated room into the cold damp atmosphere of our climate can hardly avoid irritating and inflaming this tender membrane. If our rooms were heated less intensely, and ventilated more thoroughly, so that we had not the present hothouse sensitiveness to cold air, this disease would be far less universal, and perhaps would disappear entirely. [Footnote: Dr. Gray gives the following table:
===================================================================== Rooms Occupied by Letter-press Printers. " Number " Subject to " per cent " Catarrh " Spitting " " Blood. " —————————————————————+——————+——————- 104 men having less than 500 cubic feet " " of air to breathe " 12.50 " 12.50 " " 115 men having from 500 to 600 cubic feet " " of air to breathe " 4.35 " 3.58 " " 101 men having more than 600 cubic feet " " of air to breathe " 3.96 " 1.98 ——————————————————————————————————-] (See p. 315.)
ALCOHOLIC DRINKS AND NARCOTICS.
1. ALCOHOL.
That we may understand fully the effect of alcohol upon the human system, let us first consider its nature and the process by which harmless fruits and grains are made to produce a substance so unlike themselves in its deleterious effects.
HOW ALCOHOL IS MADE.—When any substance containing sugar, as fruit juice, is caused to ferment, the elements of which the sugar is composed, viz., hydrogen, carbon, and oxygen, so rearrange themselves as to form carbon dioxide (carbonic acid), alcohol, and certain volatile oils and ethers. [Footnote: The precise relation between chemical phenomena and the physiological functions of the organic ferment is still to be discovered; and all that has been said, written, and brought forward to decide the question, need experimental proof.—SCHÜTZENBERGER.] The carbonic acid partly evaporates and partly remains in the liquor; the alcohol is the poisonous or intoxicating principle, while the oils and ethers impart the peculiar flavor and odor. Thus wine is fermented grape juice, and cider is fermented apple juice, each having its distinctive taste and smell, and each containing, as one product of fermentation, more or less of the inebriating alcohol. Wines are also made from other fruits and vegetables, such as oranges, currants, tomatoes, and rhubarb, but the alcohol which they contain is of the same nature in all cases, whether the fermented liquor has been manufactured in great quantities, by large presses, or by a simple domestic process for home consumption. It is important to remember this fact, as many people do not associate alcohol with such beverages as domestic wines and home-brewed ales, whereas it is always present with the same treacherous qualities which attach to it everywhere. An apple is a wholesome and useful fruit, and its simple juice, fragrant and refreshing, is a delight to the palate; but apple juice converted into cider and allowed to enter upon alcoholic fermentation, loses its innocence, and becomes a dangerous drink, because it is the nature of the alcohol it now contains to create an appetite for more alcohol. (See p. 185.)
WHAT IS A FERMENT?—Ferments, of which there are many varieties in nature, are minute living organisms analogous to the microscopic objects called bacteria or microbes, [Footnote: There is no well-defined limit between ferments and bacteria, any more than between ferments and fungi, or again, between fungi and bacteria. Their smaller size is the principal difference which separates bacteria from ferments, although there are bacteria of large size, such as are so frequently found in the mouth of even a healthy man, and which much resemble in their mode of growth some of the lower fungi.—Trouessart.] of which we have heard much in late years, especially in connection with the famous researches and experiments of the great French investigator, M. Pasteur. He tells us that "Every fermentation has its specific ferment. This minute being produces the transformation which constitutes fermentation by breathing the oxygen of the substance to be fermented, or by appropriating for an instant the whole substance, then destroying it by what may be termed the secretion of the fermented products." [Footnote: What we call spontaneous fermentation often occurs, as when apple juice turns to hard cider by simple exposure to the air. Science teaches us, however, that this change is always effected by the action of the busy little ferments which, wandering about, drop into the liquid, begin their rapid propagation, and, in the act of growing, evolve the products of the fermentation. "If the above liquids be left only in contact with air which has been passed through a red-hot platinum tube, and thus the living sporules destroyed; or if the air be simply filtered by passing through cotton wool, and the sporules prevented from coming into the liquid, it is found that these fermentable liquids may be preserved for any length of time without undergoing the slightest change."—Roscoe.] The effect, therefore, of fermentation is to change entirely the character of the substance upon which it acts; hence it is an error to assume that fermented liquors, as beer, wine, and cider, are safe drinks because the grains or fruits from which they are produced are healthful foods.
YEAST is a ferment which causes alcoholic fermentation. It consists of microscopic plants, which increase by the formation of multitudes of tiny cells not more than 1/2400 of an inch in diameter. In the brewing of beer they grow in great abundance, making common brewer's yeast. Ferments or their spores float in the air ready to enter any fermentable liquid, and under favorable conditions they multiply with great activity and energy. The favorable conditions include the presence of oxygen or sugar; [Footnote: Yeast, like ordinary plants, buds and multiplies even in the absence of fermentable sugar, when it is furnished with free oxygen. This multiplication, however, is favored by the presence of sugar, which is a more appropriate element than non-fermentable hydrocarbon compounds. Yeast is also able to bud and multiply in the absence of free oxygen, but in this case a fermentable substance is indispensable.—SCHÜTZENBERGER'S Fermentation.] oxygen being, as we know, necessary for the development and the reproduction of all cell life (p. 107), and ferments having the power to resolve sugar, which penetrates by endosmose into the interior of the cell, into alcohol, carbonic acid, glycerine, succinic acid, and oxygen.
BEER.—The barley used for making beer is first malted, i. e., sprouted, to turn a part of its starch into sugar. When this process has gone far enough, it is checked by heating the grain in a kiln until the germ is destroyed. The malt is then crushed, steeped, and fermented with hops and yeast. The sugar gradually disappears, alcohol is formed, and carbonic acid escapes into the air. The beer is then put into casks, where it undergoes a second, slower fermentation, and the carbonic acid gathers; when the liquor is drawn, this gas bubbles to the surface, giving to the beer its sparkling, foamy look.
WINE is generally made from the juice of the grape. The juice, or must, as it is called, is placed in vats in the cellar, where the low temperature favors a slow fermentation. If all the sugar be converted into alcohol and carbonic-acid gas, a dry wine will remain; if the fermentation be checked, a sweet wine will result; and if the wine be bottled while the change is still going on, a brisk effervescing liquor like champagne, will be formed. All these are dangerous beverages because of the alcohol they contain.
DISTILLATION.—Alcohol is so volatile that, by the application of heat, it can be driven off as a vapor from the fermented liquid in which it has been produced. Steam and various fragrant substances will accompany it, and, if they are collected and condensed in a cool receiver, a new and stronger liquor will be formed, having a distinctive odor.
In this way whiskey is distilled from fermented corn, rye, barley, or potatoes; the alcohol of commerce is distilled from whiskey; brandy, from wine; rum, from fermented molasses; and gin, from fermented barley and rye, afterward distilled with juniper berries.
VARIETIES AND PROPERTIES OF ALCOHOL.—There are several varieties of alcohol produced from distillation of various substances. Thus Methyl Alcohol is obtained from the decomposition of hard wood when exposed to intense heat with little or no oxygen present. It is a light, volatile liquid, which closely resembles ordinary alcohol in all its properties. It is used in the manufacture of aniline dyes, in making varnishes, and for burning in spirit lamps. Amyl Alcohol [Footnote: The odor of amylic alcohol is sweet, nauseous, and heavy. The sensation of its presence remains long. In taste it is burning and acrid, and it is itself practically insoluble in water. When it is diluted with common alcohol it dissolves freely in water, and gives a soft and rather unctuous flavor, I may call it a fruity flavor, something like that of ripe pears. Amyl alcohol, introduced as an adulterant, is an extremely dangerous addition to ordinary alcohol, in whatever form it is presented. From the quantities of it imported into this country, it is believed to be employed largely in the adulteration of wines and spirits.—RICHARDSON.] is the chief constituent of "fusel oil," found in whiskey distilled from potatoes. It is often present in common alcohol, giving a slightly unpleasant odor when it evaporates from the hand. Fusel oil is extremely poisonous and lasting in its effects, so that when contained in liquors it greatly increases their destructive and intoxicating properties.
Ethyl Alcohol, which is that which we have described as obtained from fermentation of fruits and grains, is the ordinary alcohol of commerce. We have spoken of its volatility. This property permits it to pass into vapor at 56° Fahr. It boils at 173° Fahr. (Water boils at 212°.) Like Methyl Alcohol, it burns without smoke and with great heat, [Footnote: Pour a little alcohol into a saucer and apply an ignited match. The liquid will suddenly take fire, burning with intense heat, but feeble light. In this process, alcohol takes up oxygen from the air, forming carbonic-acid gas, and water.—Hold a red-hot coil of platinum wire in a goblet containing a few drops of alcohol, and a peculiar odor will be noticed. It denotes the formation of aldehyde—a substance produced in the slow oxidation of alcohol. Still further oxidized, the alcohol would be changed into acetic acid—the sour principle of vinegar.—Put the white of an egg—nearly pure albumen—into a cup, and pour upon it some alcohol, or even strong brandy; the fluid albumen will coagulate, becoming hard and solid. In this connection, it is well to remember that albumen is contained in our food, while the brain is largely an albuminous substance.] and is therefore of much value in the arts. Its great solvent power over fats and mixed oils renders it a useful agent in many industrial operations. It is also a powerful antiseptic, and no one who visits a museum of natural history will be likely to forget the rows of bottles within which float reptilian and batrachian specimens, preserved in alcohol.
To alcohol, also, we are indebted for various anÆsthetic agents, which, when not abused (p. 340), are of inestimable value. Thus, if certain proportions of alcohol and nitric acid be mixed together and heated, nitrite of amyl, so serviceable in relieving the agonizing spasms peculiar to that dread disease, angina pectoris, will be obtained. If, instead of nitric, we use sulphuric acid, we shall get ether; if chlorine be passed through alcohol, hydrate of chloral is the result; and, if chloride of lime and alcohol be treated together, the outcome is chloroform.
One of the most striking properties of alcohol, and one which we shall hereafter consider in its disastrous effects upon the tissues of our body, is its affinity for water. [Footnote: Suppose, then, a certain measure of alcohol be taken into the stomach, it will be absorbed there, but, previous to absorption, it will have to undergo a proper degree of dilution with water; for there is this peculiarity respecting alcohol when it is separated by an animal membrane from a watery fluid like the blood, that it will not pass through the membrane until it has become charged, to a given point of dilution, with water. Alcohol is itself, in fact, so greedy for water that it will pick it up from watery textures, and deprive them of it until, by its saturation, its power of reception is exhausted, after which it will diffuse into the current of circulating fluid.
To illustrate this fact of dilution I perform a simple experiment. Into a bladder is placed a mixture consisting of equal parts of alcohol and distilled water. Into the neck of the bladder a long glass tube is inserted and firmly tied. Then the bladder is immersed in a saline fluid representing an artificial serum of blood. The result is, that the alcohol in the bladder absorbs water from the surrounding saline solution, and thereby a column of fluid passes up into the glass tube. A second mixture of alcohol and water, in the proportion this time of one part of alcohol to two of water, is put into another bladder immersed in like manner in an artificial serum. In this instance a little fluid also passes from the outside into the bladder, so that there is a rise of water in the tube, but less than in the previous instance. A third mixture, consisting of one part of alcohol with three parts of water, is placed in another little bladder, and is also suspended in the artificial serum. In this case there is, for a time, a small rise of fluid in the tube connected with the bladder; but after a while, owing to the dilution which took place, a current from within outward sets in, and the tube becomes empty. Thus each bladder charged originally with the same quantity of fluid contains at last a different quantity. The first contains more than it did originally, the second only a little more, the third a little less. From the third, absorption takes place, and if I keep changing and replacing the outer fluid which surrounds the bladder with fresh serum, I can in time, owing to the double current of water into the bladder through its coats, and of water and alcohol out of the bladder into the serum, remove all the alcohol. In this way it is removed from the stomach into the circulating blood after it has been swallowed. When we dilute alcohol with water before drinking it, we quicken its absorption. If we do not dilute it sufficiently, it is diluted in the stomach by transudation of water in the stomach, until the required reduction for its absorption; the current then sets in toward the blood, and passes into the circulating canals by the veins.—RICHARDSON.] When strong alcohol is exposed to the air, it absorbs moisture and becomes diluted; at the same time, the spirit itself evaporates. The commercial or proof spirit is about one half water; the strongest holds five per cent; and to obtain absolute or waterless alcohol, requires careful distillation in connection with some substance, as lime, that has a still greater affinity for water, and so can despoil the alcohol.
ALCOHOL IN ITS DESTRUCTIVE RELATION TO PLANT AND ANIMAL LIFE.—If we pour a little quantity of strong spirits upon a growing plant in our garden or conservatory, we shall soon see it shrivel and die. If we apply it to insects or small reptiles which we may have captured for specimens in our cabinet, the same potent poison will procure for them a speedy death. If we force one of our domestic animals to take habitual doses of it, the animal will not only strongly protest against the unnatural and nauseous potion, but it will gradually sicken and lose all power for usefulness. "If I wished," says a distinguished English physician, "by scientific experiment to spoil for work the most perfect specimen of a working animal, say a horse, without inflicting mechanical injury, I could choose no better agent for the purpose of the experiment than alcohol." [Footnote: "The effects produced by alcohol are common, so far as I can discover, to every animal. Alcohol is a universal intoxicant, and in the higher orders of animals is capable of inducing the most systematic phenomena of disease. But it is reserved for man himself to exhibit these phenomena in their purest form, and to present, through them, in the morbid conditions belonging to his age, a distinct pathology. Bad as this is, it might be worse; for if the evils of alcohol were made to extend equally to animals lower than man, we should soon have none that were tamable, none that were workable, and none that were eatable."]
ALCOHOL IN WINE, BEER, AND CIDER IDENTICAL WITH ALCOHOL IN ARDENT SPIRITS.—In all liquors the active principle is alcohol. It comprises from six to eight per cent of ale and porter, seven to seventeen per cent of wine, and forty to fifty per cent of brandy and whiskey. All these may therefore be considered as alcohol more or less diluted with water and flavored with various aromatics. The taste of different liquors—as brandy, gin, beer, cider, etc.—may vary greatly, but they all produce certain physiological effects, due to their common ingredient—alcohol. "In whatever form it enters," says Dr. Richardson, "whether as spirit, wine, or ale, matters little when its specific influence is kept steadily in view. To say this man only drinks ale, that man only drinks wine, while a third drinks spirits, is merely to say, when the apology is unclothed, that all drink the same danger." In other words, the poisonous nature of alcohol, and the effects which result when it is taken into the stomach, are definite and immutable facts, which are not dependent upon any particular name or disguise under which the poison finds entrance.
We shall learn, as we study the influence of alcohol upon the human system, that one of its most subtle characteristics is the progressive appetite for itself (p. 185) which it induces, an appetite which, in many cases, is formed long before its unhappy subject is aware of his danger. The intelligent pupil, who knows how to reason from cause to effect, needs hardly to be told, in view of this physical truth, of the peril that lies in the first draught of any fermented liquor, even though it be so seemingly harmless as a glass of home-brewed beer or "slightly-beaded" cider. Few of us really understand our own inherent weakness or the hereditary proclivities (p. 186) that may be lurking in our blood, ready to master us when opportunity invites; but we may be tolerably certain that if we resolutely refuse to tamper with cider, beer, or wine, we shall not fall into temptation before rum, gin, or brandy. Since we know that in all fermented beverages there is present the same treacherous element, alcohol, we are truly wise only when we decline to measure arms in any way with an enemy so seductive in its advances, so insidious in its influence, and so terrible in its triumph. [Footnote: Aside from all considerations of physical, mental, and moral injury wrought by the use of alcoholic drinks, every young man may well take into account the damaging effect of such a dangerous habit upon his business prospects. Careful business men are becoming more and more unwilling to take into their employ any person addicted to liquor drinking. Within the past few years the officers of several railroads, having found that a considerable portion of their losses could be directly traced to the drinking habits of some one or more of their employÉs, have ordered the dismissal of all persons in their service who were known to use intoxicants, with the additional provision that persons thus discharged should never be reinstated. Many Eastern manufactories have adopted similar rules. All mercantile agencies now report the habits of business men in this respect, and some life insurance companies refuse to insure habitual drinkers, regarding such risks as "extra-hazardous."]
Let us now consider the physiological effects of alcohol upon the organs immediately connected with the circulation of the blood.
GENERAL EFFECT OF ALCOHOL UPON THE CIRCULATION.—During the experiment described on page 118, the influence of alcohol upon the blood may be beautifully tested. Place on the web of the frog's foot a drop of dilute spirit. The blood vessels immediately expand—an effect known as "Vascular enlargement." Channels before unseen open, and the blood disks fly along at a brisker rate. Next, touch the membrane with a drop of pure spirit. The blood channels quickly contract; the cells slacken their speed; and, finally, all motion ceases. The flesh shrivels up and dies. The circulation thus stopped is stopped forever. The part affected will in time slough off. Alcohol has killed it.
The influence of alcohol upon the human system is very similar. When strong, as in spirits, it acts as an irritant, narcotic poison (p. 142, note). Diluted, as in fermented liquors, it dilates the blood vessels, quickens the circulation, hastens the heart throbs, and accelerates the respiration.
THE EFFECT OF ALCOHOL UPON THE HEART.—What means this rapid flow of the blood? It shows that the heart is overworking. The nerves that lead to the minute capillaries and regulate the passage of the vital current through the extreme parts of the body, are paralyzed by this active narcotic. The tiny blood vessels at once expand. This "Vascular enlargement" removes the resistance to the passage of the blood, and a rapid beating of the heart results. [Footnote: Dr. B. W. Richardson's experiments tend to prove that this apparently stimulating action of alcohol upon the heart is due to the paralysis of the nerves that control the capillaries (Note, p. 208), which ordinarily check the flow of the blood (p. 117). The heart, like other muscles under the influence of alcohol, really loses power, and contracts less vigorously (p. 183). Dr. Palmer, of the University of Michigan, also claimed that alcohol, in fact, diminishes the strength of the heart. Prof. Martin, of Johns Hopkins University, from a series of carefully conducted experiments upon dogs, concluded that blood containing one fourth per cent of alcohol almost invariably diminishes within a minute the work done by the heart; blood containing one half per cent always diminishes it, and may reduce the amount pumped out by the left ventricle so that it is not sufficient to supply the coronary arteries. One hundred years ago, alcohol was always spoken of as a stimulant. Modern experiment and investigation challenged that definition, and it is now classified as a narcotic. There are, however, able physicians who maintain that, taken in small doses, and under certain physical conditions, it has the effect of a stimulant. All agree that, when taken in any amount, it tends to create an appetite for more.]
Careful experiments show that two ounces of alcohol—an amount contained in the daily potations of a very moderate ale or whiskey drinker—increase the heart beats six thousand in twenty-four hours;—a degree of work represented by that of lifting up a weight of seven tons to a height of one foot. Reducing this sum to ounces and dividing, we find that the heart is driven to do extra work equivalent to lifting seven ounces one foot high one thousand four hundred and ninety-three times each hour! No wonder that the drinker feels a reaction, a physical languor, after the earliest effects of his indulgence have passed away. The heart flags, the brain and the muscles feel exhausted, and rest and sleep are imperatively demanded. During this time of excitement, the machinery of life has really been "running down." "It is hard work," says Richardson, "to fight against alcohol; harder than rowing, walking, wrestling, coal heaving, or the treadmill itself."
All this is only the first effect of alcohol upon the heart. Long- continued use of this disturbing agent causes a "Degeneration of the muscular fiber," [Footnote: This "Degeneration" of the various tissues of the body, we shall find, as we proceed, is one of the most marked effects of alcoholized blood. The change consists in an excess of liquid, or, more commonly, in a deposit of fat. This fatty matter is not an increase of the organ, but it takes the place of a part of its fiber, thus weakening the structure, and reducing the power of the tissue to perform its function. Almost everywhere in the body we thus find cells—muscle cells, liver cells, nerve cells, as the case may be—changing one by one, under the influence of this potent disorganizer, into unhealthy fat cells. "Alcohol has been well termed," says the London Lancet, "the 'Genius of Degeneration.'"
The cause of this degeneration can be easily explained. The increased activity of the circulation compels a correspondingly increased activity of the cell changes: but the essential condition of healthful change—the presence of additional oxygen—is wanting (see p. 143), and the operation is imperfectly performed.—BRODIE.] so that the heart loses its old power to drive the blood, and, after a time, fails to respond even to the spur of the excitant that has urged it to ruin.
INFLUENCE UPON THE MEMBRANES.—The flush of the face and the bloodshot eye, that are such noticeable effects of even a small quantity of liquor, indicate the condition of all the internal organs. The delicate linings of the stomach, heart, brain, liver, and lungs are reddened, and every tiny vein is inflamed, like the blushing nose itself. If the use of liquor is habitual, this "Vascular enlargement," that at first slowly passed away after each indulgence, becomes permanent, and now the discolored, blotched skin reveals the state of the entire mucous membrane.
We learned on page 55 what a peculiar office the membrane fills in nourishing the organs it enwraps. Anything that disturbs its delicate structure must mar its efficiency. Alcohol has a wonderful affinity for water. To satisfy this greed, it will absorb moisture from the tissues with which it comes in contact, as well as from their lubricating juices. The enlargement of the blood vessels and their permanent congestion must interfere with the filtering action of the membrane. In time, all the membranes become dry, thickened, and hardened; they then shrink upon the sensitive nerve, or stiffen the joint, or enfeeble the muscle. The function of these membranes being deranged, they will not furnish the organs with perfected material, and the clogged pores will no longer filter their natural fluids. Every organ in the body will feel this change.
EFFECT UPON THE BLOOD. [Footnote: Alcohol acts upon the oxygen carrier, the coloring matter of the red corpuscles, causing it to settle in one part of the globule, or even to leave the corpuscle, and deposit itself in other elements of the blood. Thus the red corpuscle may become colorless, distorted, shrunken, and even entirely broken up—Dr. G. B. HARRIMAN.]— From the stomach, alcohol passes directly into the circulation, and so, in a few minutes, is swept through the entire system. If it be present in sufficient amount and strength, its eager desire for water will lead it to absorb moisture from the red corpuscles, causing them to shrink, change their form, harden, and lose some of their ability to carry oxygen; it may even make them adhere in masses, and so hinder their passage through the tiny capillaries.—RICHARDSON.
With most persons who indulge freely in alcoholic drinks, the blood is thin, the avidity of alcohol for water causing the burning thirst so familiar to all drinkers, and hence the use of enormous quantities of water, oftener of beer, which unnaturally dilutes the blood. The blood then easily flows from a wound, and renders an accident or surgical operation very dangerous.
When the blood tends, as in other cases of an excessive use of spirits, to coagulate in the capillaries, [Footnote: The blood is rendered unduly thin, or is coagulated, according to the amount of alcohol that is carried into the circulatory system. "The spirit may fix the water with the fibrin, and thus destroy the power of coagulation; or it may extract the water so determinately as to produce coagulation. This explains why, in acute cases of poisoning by alcohol, the blood is sometimes found quite fluid, at other times firmly coagulated in the vessels."—B. W. RICHARDSON.]
Reckless persons have sometimes drunk a large quantity of liquor for a wager, and, as the result of their folly, have died instantly. The whole of the blood in the heart having coagulated, the circulation was stopped, and death inevitably ensued.] there is a liability of an obstruction to the flow of the vital current through the heart, liver, lungs, etc., that may cause disease, and in the brain may lay the foundation of paralysis, or, in extreme cases, of apoplexy.
Wherever the alcoholized blood goes through the body, it bathes the delicate cells with an irritating narcotic poison, instead of a bland, nutritious substance.
EFFECT UPON THE LUNGS.—Here we can see how certainly the presence of alcohol interferes with the red corpuscles in their task of carrying oxygen. "Even so small a quantity as one part of alcohol to five hundred of the blood will materially check the absorption of oxygen in the lungs."
The cells, unable to take up oxygen, retain their carbonic-acid gas, and so return from the lungs, carrying back, to poison the system, the refuse matter the body has sought to throw off. Thus the lungs no longer furnish properly oxygenized blood.
The rapid stroke of the heart, already spoken of, is followed by a corresponding quickening of the respiration. The flush of the cheek is repeated in the reddened mucous membrane lining the lungs.
When this "Vascular enlargement" becomes permanent, and the highly albuminous membrane of the air cells is hardened and thickened as well as congested, the Osmose of the gases to and fro through its pores can no longer be prompt and free as before. Even when the effect passes off in a few days after the occasional indulgence, there has been, during that time, a diminished supply of the life-giving oxygen furnished to the system; weakness follows, and, in the case of hard drinkers, there is a marked liability to epidemics. [Footnote: There is no doubt that alcohol alters and impairs tissues so that they are more prone to disease.—DR. G. K. SABINE. A volume of statistics could be filled with quotations like the following: "Mr. Huber, who saw in one town in Russia two thousand one hundred and sixty persons perish with the cholera in twenty days, said: 'It is a most remarkable circumstance that persons given to drink have been swept away like flies. In Tiflis, with twenty thousand inhabitants, every drunkard has fallen,—all are dead, not one remaining.'"]
Physicians tell us, also, that there is a peculiar form of consumption known as Alcoholic Phthisis caused by long-continued and excessive use of liquor. It generally attacks those whose splendid physique has enabled them to "drink deep" with apparent impunity. This type of consumption appears late in life and is considered incurable. Severe cases of pneumonia are also generally fatal with inebriates. [Footnote: The Influence of Alcohol is continued in the chapter on Digestion.]
PRACTICAL QUESTIONS.
1. Why does a dry, cold atmosphere favorably affect catarrh?
2. Why should we put on extra covering when we lie down to sleep?
3. Is it well to throw off our coats or shawls when we come in heated from a long walk?
4. Why are close-fitting collars or neckties injurious?
5. Which side of the heart is the more liable to inflammation?
6. What gives the toper his red nose?
7. Why does not the arm die when the surgeon ties the principal artery leading to it?
8. When a fowl is angry, why does its comb redden?
9. Why does a fat man endure cold better than a lean one?
10. Why does one become thin, during a long sickness?
11. What would you do if you should come home "wet to the skin"?
12. When the cold air strikes the face, why does it first blanch and then flush?
13. What must be the effect of tight lacing upon the circulation of the blood?
14. Do you know the position of the large arteries in the limbs, so that in case of accident you could stop the flow of blood?
15. When a person is said to be good-hearted, is it a physical truth?
16. Why does a hot footbath relieve the headache?
17. Why does the body of a drowned or strangled person turn blue?
18. What are the little "kernels" in the armpits?
19. When we are excessively warm, would the thermometer show any rise of temperature in the body?
20. What forces besides that of the heart aid in propelling the blood?
21. Why can the pulse be best felt in the wrist? 22. Why are starving people exceedingly sensitive to any jar?
23. Why will friction, an application of horse-radish leaves, or a blister relieve internal congestion?
24. Why are students very liable to cold feet?
25. Is the proverb that "blood is thicker than water" literally true?
26. What is the effect upon the circulation of "holding the breath"?
27. Which side of the heart is the stronger?
28. How is the heart itself nourished? [Footnote: The coronary artery, springing from the aorta just after its origin, carries blood to the muscular walls of the heart; the venous blood comes back through the coronary veins, and empties directly into the right auricle.]
29. Does any venous blood reach the heart without coming through the venÆ cavÆ?
30. What would you do, in the absence of a surgeon, in the case of a severe wound? (See p. 258.)
31. What would you do in the case of a fever? (See p. 263.)
32. What is the most injurious effect of alcohol upon the blood?
33. Are our bodies the same from day to day?
34. Show how life comes by death.
35. Is not the truth just stated as applicable to moral and intellectual, as to physical life?
36. What vein begins and ends with capillaries? Ans. The portal vein commences with capillaries in the digestive organs, and ends with the same kind of vessels in the liver. (See p. 166.)
37. By what process is alcohol always formed? Does it exist in nature?
38. What percentage of alcohol is contained in the different kinds of liquor?
39. Does cider possess the same intoxicating principle as brandy?
40. Describe the general properties of alcohol.
41. Show that alcohol is a narcotic poison.
42. If alcohol is not a stimulant, how does it cause the heart to overwork?
43. Why is the skin of a drunkard always red and blotched?
44. What danger is there in occasionally using alcoholic drinks?
45. What is meant by a fatty degeneration of the heart?
46. What keeps the blood in circulation between the beats of the heart?
47. What is the office of the capillaries? (See note, p. 373.)
48. Does alcohol interfere with this function?
49. How does alcohol interfere with the regular office of the membranes?
