iOj' THE GIFT OF ....J.^...rOJiiL>:^.jX?:^^^ Aa..»±'S.31.5- i3/5:i?3. Cornell University Library 3 1924 031 267 671 olin.anx a Cornell University y Library The original of tliis book is in tlie Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31 924031 267671 BY ALBERT F. BLAISDELL M.D. A.M. Blaisdell's Revised Series of Physiologies NET MAILING PRICE PHYSIOLOGY FOR LITTLE FOLKS A REVISED EDITION OF THE CHILD'S BOOK OF HEALTH In Easy Lessons for Schools Illustrated . 35c. PHYSIOLOGY FOR BOYS AND GIRLS A REVISED EDITION OF HOW TO KEEP WELL A Text-Book of Health for use in the lower grade of Schools with especial reference to the effects of Alcoholic Drinks Tobacco and other Narcotics on the bodily life. Illustrated 47c. YOUNG FOLKS' PHYSIOLOGY A REVISED EDITION OF OUR BODIES AND HOW WE LIVE An elementary Text-Book of Physiology and Hygiene for use in the Common Schools with special reference to the effects of Stimulants and Narcotics on the Human System. Illustrated 67c. The above excellent text books are indorsed by Mrs. Mary H. Hunt, National and International. Superintendent of the Scientific Department of the Woman's Christian Temperance Union, and by the Advisory Board. STUDY OF THE ENGLISH CLASSICS. A Practical Hand-Book for Teachers — being a Guide to English Literature . . $1.15 FIRST STEPS WITH AMERICAN AND BRITISH AUTHORS. English Literature for Young People 85c. READINGS FROM THE WAVERLEY NOV- ELS. Edited for School and Home Use . S5c. STORIES OF THE CIVIL WAR. Illustrated Boards 35c. Library Edition $I.OO STORIES FROM ENGLISH HISTORY. Illustrated Boards 35c. Library Edition $1.00 LEE AND SHEPARD PUBLISHERS BOSTON 10 Milk Street next Old South Meetinq-House Young Folks' Physiology A REVISED EDITION OF OUR BODIES AND HOW WE LIVE AN ELEMENTARY TEXT-BOOK OF PHYSIOLOGY AND HYGIENE WITH SPECIAL REFERENCE TO THE EFFECTS OF STIMULANTS AND NARCOTICS ON THE • HUMAN SYSTEM, FOR USE IN SCHOOLS BY ALBERT F. BLAISDELL M.D. AUTHOR OF '* PHYSIOLOGY FOR BOYS AND GIRLS " '* PHY'SIOLOGY FOR LITTLE FOLKS," ETC. We learn to live by living to learn. BOSTON LEE AND SHEPARD PUBLISHERS 10 MILK STREET Jk 1893 Copyright, 1S84, by Lee and Shefard Copyright, 1892, by Lee and Shepard All Rights Reserved Young Folks' Physiology A Revised Edition of Our Bodies and HDw We Live S. J. PARKHILL & CO., PRINTERS 226 FRANKLIN STREET BOSTON PREFACE REVISED EDITION It has been the aim of the author in making this text-book, for the use of common schools, to present clearly and tersely the most important and interesting facts concerning our bodily life. To keep any machine in good running-order, we must know something of the structure and use of its various parts. So when we come to the study of this wonderful and complex machine, the human body, we must master such facts of its anatomy and physiology as are essential to a proper understanding of the simple laws of health. The real object of studying physiology in schools is to teach young folks how to keep well and strong, and to avoid evil habits that destroy character as well as health. Hence, special emphasis has been laid upon such points as have a bearing upon our personal health. It is now generally admitted that actual observation and actual experiment are as necessary in the study of elementary physiology as in any other branch of science. We must handle the skeleton itself if we wish IV PREFACE to get a fair idea of its bones. We must examine a drop of blood under the microscope if we would know how blood looks. Hence, as supplementary to the text itself, we have added a series of practical experi- ments. Most of them are simple, and require only a little painstaking and an inexpensive apparatus to do successfully. These experiments should be actually performed, and not merely read as a part of the text. This book has been thoroughly revised. New sec- tions and new chapters have been added, while others have been rewritten and rearranged. The new chap- ter on Physical Exercise, supplemented by a series of gymnastic exercises, will prove an attractive feature to those who realize the importance of physical culture to our young folks. The author has aimed to make everything plain by using a simple and homely style of writing. In the preparation of this revised and enlarged edition, the author and publishers are under deep obligations to Mrs. Mary H. Hunt, the Superintend- ent of the Department of Scientific Instruction of the National Woman's Christian Temperance Union, who has carefully revised the book. Albert F. Blaisdell. Providence, R.I., June, 1892. CONTENTS CHAPTER I Introduction .... i CHAPTER H The Bony Framework . 13 CHAPTER HI The Muscles . 42 CHAPTER IV Physical Exercise 56 CHAPTER V Food and Drink . . 70 CHAPTER VI Origin and Nature of Fermented Drinks . . . 8i CHAPTER VII Digestion .92 CHAPTER VIII The Blood and Its Circulation . . . 122 CHAPTER IX Breathing • . 142 V VI CONTENTS CHAPTER X PAGE How Our Bodies are covered i6i CHAPTER XI The Nervous System 177 CHAPTER XH The Special Senses 210 CHAPTER Xni Excretion . 235 CHAPTER XIV The Throat and Voice 243 CHAPTER XV Simple Matters of Every-day Health. — What to do, and How to do It .... . . 249 CHAPTER XVI Practical Experiments 280 Review Analysis . . . . ' 329 Text Questions for Review 331 Notes . . . . 355 Appendix 375 Glossary . 391 Index 405 FOR ADVANCED SCHOOLS YOUNG FOLKS' PHYSIOLOGY A REVISED EDITION OF "OUR BODIES AND HOW WE LIVE" An elementary treatise on Physiology and Hygiene for families and schools, witli especial reference to the effects of alcoholic drinks, tobacco, and other narcotics on the human system. Illustrated. FOR LOWER SCHOOLS PHYSIOLOGY FOR BOYS AND GIRLS A REVISED EDITION OF "HOW TO KEEP WELL" A text-book of health for use in the lower grades of schools, with special reference to the effects of alcoholic drinks, tobacco, and other narcotics on the bodily life. Illustrated. FOR PRIMARY SCHOOLS PHYSIOLOGY FOR LITTLE FOLKS A REVISED EDITION OF "THE CHILD'S BOOK OF HEALTH". In easy lessons for younger scholars. Illustrated. INDORSEMENT This series of books having been revised under our advice and supervision, and containing a full and fair treatment of the nature and effects of alcoholic drinks, tobacco, and other narcotics, in con- nection with relative Physiology and Hygiene, expressed in lan- guage which pupils — in the grades for which the books are intended — can readily comprehend, we take great pleasure in recommending the same for use as SCHOOL TEXT-BOOKS. MJBY H. HUNT ADVISORY BOARD National and International Albert H. Plumb, D.n. Superintendent Department ,-, . , T, , ^ », T. of Scientific Instruction of tie Darnel Dorchester. D.D. tjt- < ^; • j- t. j. ' Woman s Christian Temfer- Hon. William. E. Sheldon. ance Union. Life Director of National Educational Associ- Rev. Joseph Cook, ation. December 5, 1891. YOUNG FOLKS' PHYSIOLOGY CHAPTER I INTRODUCTION I. Animafl Life. — We need not be told that we have bodies made of flesh and bone, whose substance we see and handle every day of our life. Even a child knows that certain parts of his body, as the walls of his chest, and his heart that he feels beating within it, are always moving of themselves. We can move of our own free will from one place to another. The wind may rustle the leaves, and a breeze may sway a strong oak ; but the leaves and the oak have no power to move of themselves. We need not wait, like the trees of the forest, for the wind to blow us to and fro, or, like the pebbles by the roadside, for some one to stir us. Like the horse, dog, bird, or any other animal that has life, we can move from place to place. Every living animal, from ourselves down to the tiniest creature that lives its brief life in a single day, and that cannot be seen without the aid of the micro- scope, has the power to move of itself. Again, every child must see for himself that he is warm. Even in the coldest day of midwinter, let the stones and trees be as cold as the winter wind, our I 2 YOUNG FOLKS' PHYSIOLOGY bodies, except perhaps the tips of the fingers and toes, are always warm. The horse, dog, and even the birds and the bees, are warm. All animals, in fact, are more or less warm as long as they are alive. 2. The Body compared to a Locomotive. — Our bodies are in some respects very much like the locomo- tive. The bones and muscles answer to the m'achinery of the engine, and the motive-power is produced by the food we eat. We put fuel into the furnace. The water in the boiler is heated and expands into stfeam. Then the piston begins to work to and fro ; this moves the wheels, joints, and levers : and so the whole engine is set going by the fuel which is put into the furnace. Now, just the same thing occurs in our bodies. We take food, and that food passes into the stomach. By reason of that food, we are kept warm, muscular force is developed, and the levers and joints within us are set working, as we see in the locomotive. There is, however, an important difference between the two. The locomotive is all the time wearing itself out. It must be stopped, taken to pieces, and repaired by the machinist. So our bodies are all the time wearing out, but they are constantly repairing themselves. We take food, not only to warm us, but also for the building-up and repairing of our bodies. Remember, then, that the body far surpasses the engine in the perfection of its mechanism, inasmuch as it is self-repairing. 3. The Body and its Nervous System. — If we exert our will, or " make up our mind " as we call it, to ' cross the room, to write with a pen, to pick a flower, to INTRODUCTION 3 eat an apple, or to repeat some familiar maxim, we can do it. The mind, or brain, wills to do this or that thing. It sends out its order by the tiny, white, thread- like cords called nerves ; and the muscles are put in motion to do whatever the brain has willed them to do. Every child must have noticed, that when he pricks his fingers with a needle, touches a hot stove, or has eaten some unwholesome food, like an unripe apple, pain is produced. These same silvery-white cords, like telegraph-wires, carry special despatches to the central station ; that is, the brain : and the feeling of pain is there made known. This is the way every part of our bodies is watched over and protected. If it were not so, we should be continually hurting ourselves. This mind, which feels and thinks, but which we cannot see, forms the essen- tial part of our being. It is the power to feel, to know, to think, to reason, and to will, that makes us what we are. Our bodies are ever busy. We eat, drink, and sleep. We move about, and are warm. We feel, hear, see, talk, breathe, and think. We do not wonder about it^ simply because it is so common. ' When we do stop to think about it, how wonderful it is simply to be alive ! What study could be more important, interesting, and even fascinating, than that which has to do with the working of our own bodies ! We gaze with wonder and admiration at the marvellous work of some intricate machine made by man. Well we may, for it seems endowed with life. But, in the human body, we find, the more we study and think about it, not simply a most perfect and delicate machine, but one endowed with life, — a mind, — a soul. 4 YOUNG FOLKS PHYSIOLOGY Indeed, the more we study, and the longer we live, and reflect upon it, the more we shall realize the great fact that the All-wise Creator, in his goodness and wis- dom, has made for us bodies, which, in the words of the Psalmist, are "fearfully and wonderfully made." 4. Anatomy, Physiology, and Hygiene. — Before we can tell how plants and animals live, we must know what animals and plants are. A watchmaker would be una- ble to describe the working of a watch or clock unless he first made himself acquainted with the various parts of which watches and clocks .are made. So it is with the study of human beings. /We must know the struc- ture of their bodies. before we can understand the man- ner in which these bodies act and move, or, in one word, live. \ The science which tells us about the structure, form, and position of the different parts of the body, is called anatomy.! It tells us what they are, where they are, and how they look. The science which explains the uses or functions of the different parts of the body is called physiology, meaning "a story about nature." Now, after we have learned something about the structure and uses of different parts of the body, we should learn how to take care of these parts, and how to keep them in health. We do this by the study of hygiene,^ or the science which tells us about health. ^ The word " anatomy " comes from the Greek, meaning " ^cutting through," or dissection ; that is, the act of cutting an animal in pieces for the purpose of study. 2 The word " hygiene " is derived from the name of the Greek goddess Hygeia, who is said to liave watched over the health of the people. INTRODUCTION 5 Take the stomach for an illustration. If we learn what it is, where it is, how it looks, its shape, size, and general appearance, its coats, etc., this would be its anatomy. If we learn for what special purpose it is made, just what these different parts do, and how they do it, this would be its physiology. Finally, if we learn what might interfere with the proper working of each part, and how it is kept in good order, — what will injure its health, and what will do it good, — this would be its hygiene. 5. Some Technical Words Explained. ^ A child soon learns by experience many things about such parts of his body as the eye, the ear, the nose, the hands and feet, the tongue, and so on. Now, you must already know that there are other distinct parts inside of our bodies, although we cannot see them. You have doubtless heard of some of these parts, such as the heart, the brain, the stomach, the liver, and the lungs. It is usual to speak of these as the organs of the body., An organ is a special part of the body which performs a special work. Thus the eye is the organ of sight,, the nose of smell, the ear of hearing, the' stoniach of digestion, the lungs of breathing, and so on. A number of organs, similar in structure, of differ- ent size and shape, extending throughout the body, are called a system. Thus we speak of the nervous sys- tem, the arterial system, etc. Several organs, different in structure, but so arranged as to work together for some special end are called an apparatus. Thus the stomach and liver make up a part of the digestive apparatus. 6 YOUNG folks' physiology The special work which an organ has to do is said to be the function or use of that organ : thus it is the function of the eye to see, and of the liver to secrete bile. We speak of the body as being an organized struc- ture because it consists of a number of organs, each performing some function necessary to the whole. One important fact must be borne in mind. Although each of these organs is placed in a distinct part of the body, and has its own special work to do, yet none exists and works for itself alone. The special work which eachperforms is necessary for the general well-being of the body as a whole, and cannot be carried on by another organ. Some of the organs are more intimately connected with the life of the body than others. We often speak of them as the "Vital Fig. I. -Portion of a lining lis- Organs. If any one of these be sue showing its bundles and filaments , . . of fibrous tissue, crossing in every dlseaSCd Ot injured, SO that it Z:^.^:Z:^^ cannot carry on its proper work, magnified. the rcst of the organs sooner or later suffer too, cease to perform their functions, and death ensues. The organs and other parts of the body are composed of a variety of substances or materials. These we shall call the tissnes of the body. They may be com- pared to the timber, stone, bricks, mortar, iron, lead, glass, and other materials, which, properly arranged, make up a dwelling-house. The principal tissues INTRODUCTION 7 which make up the body are bone, or osseous tissue ; muscle, or muscular tissue ; cartilage, or gristle ; fat and nerve tissue. 6. Minute Structure of the Body. — When we examine any part of the body with the microscope, we find it made up mainly of fibres, fluids, and cells. The original element out of which every other element of the body is formed is the cell. The fibres serve to give firmness to the tissues or organs and to bind the most minute parts of the body together. Fibres r,3. ,._with uood-ceUs are properly whitish or yellowish '" ■'^p''* motion, .as seen under the microscope. threads, slender as one can imagine. Some are elastic ; others are not, but very tough and strong. The cells are so small that we must use a powerful microscope to see them at all. In a general way we may compare them to the tiniest bags filled with a semi-fluid mass, in which another still smaller bag floats, and is called the nucleus' of the larger one. Cells are of all shapes and sizes, round, flat, thick, and long. Thus, we shall learn in a succeeding chapter of the rounded cells, or corpuscles, which float in the blood, and of the flattened cells which can be scraped from the outer or scarf skin. The life of a cell is one of ceaseless change. It is ever changing its form. If we watch the cells under a microscope, we find them dividing themselves into parts with the greatest rapidity. In their never-ending changes, they are doing a remarkable work in our bodies. 8 YOUNG FOLKS PHYSIOLOGY Some change their forms, and become muscle : others become fluids, which help digest our food. The liver- cells manufacture or secrete the bile, and the bone-cells help make the bones. Mil- FiG. 3. — Showing how a cell divides Hons of blood-cclls do their into two „ew cells, each with itsnucleus,as ^^^^.j^ ^^^ perish CVerV daV, seen under the microscope. ^ -' -^ while the brain-cells act in some mysterious way to help us think. In short, our very life exists in the cell. 7. Chemical Elements found in the Body. — If we put aside the microscope, and call upon the chem- ist to -help us, he will tell us that there are about^ sev- enty different elements known to chemistry. Of these, only sixteen exist in our bodies. The most important are carbon, hydrogen, nitrogen, oxygen, sulphur, iron, phosphorus, soda, potash, lime, and magnesium. Thus, there is iron in the blood, lime in the bones, soda in the bile, and potash in the muscles. Very few of these elements exist as such in the body. They are mainly found as chemical compounds. Thus, water, a combination of oxygen and hydrogen, forms about two-thirds of the weight of the body ; and the average human body contains about six ounces of common salt, which is a form of soda. 8. General Build of the Body. — If we look at the human body, we cannot help noticing that it is made up of a middle, nearly round portion, which is called the trunk. On the top of this is placed a kind of round ball, called the head; while two pairs of branches, called the extremities, are attached to the upper and lower corners of the trunk. INTRODUCTION Again, we notice that the whole body has an outer covering, which is called the skin. Underneath the skin lie soft masses of red flesh, called the muscles. These muscles are mostly fastened to the hard parts, or bones. These bones make up the framewofk of our bodies. There are about two hundred separate bones in the body, which they serve to sup port. Taken together, they form the skeleton. The limbs are solid ; but the head is hollow, and holds an organ called the brain, which is the centre of the nervous system A cheesy-like, silvery-white cord, called the spinal cord, runs from the brain down the middle of the backbone, and sends its thread- like branches, called nerves, all over the body. It is through the nervous system that we are able to think or feel, or, in fact, to know anything. The trunk is also hollow. It is divided into an upper and a f>g-4. — side view, showing the Diaphragm separating the lower room by means of a parti- chest and Abdomen, tion called the diapliragm. The upper room is called the chest, and holds the heart and the lungs. The lower room is called the abdomen, and holds the stomach, liver, intestines, and other vital organs. 10 YOUNG FOLKS PHYSIOLOGY 9. General Plan of Study. — We shall now proceed to study some of the most simple facts about the human ' body, together with the laws of Hygiene that must be obeyed to insure its health. f iG. 5. — Contents of the Chest and Abdomen. Special emphasis will be laid upon the nature and the effects of alcoholic drinks, tobacco, and other narcotics. Reference will be made to the value and importance of physical culture. For convenience the whole subject will be considered under the following general topics : — INTRODUCTION 1 1 GENERAL TOPICS. 1. The Skeleton, or bony framework. 2. Mnscles, or the fleshy parts. 3. Physical Exercise in Schools. 4. Food and Drink. 5. Origin and Nature of Fermented Drinks. G. The Digestion of Food. 7. The Blood and its Circulation. 8. The Respiration, or Breathing. 9. The Skin, or Outer Covering. 10. The Nervous System and the Brain. 11. The Special Senses. 12. Excretion, or getting rid of waste matter. 13. The Throat and the Voice. 1. The skeleton, or bony framework, consists of about two hundred bones of various shapes and sizes. It forms the main support of our bodies, and serves to protect the vital organs within. 2. The mnscles are the fleshy or lean parts of the body ; and they, together with the fat, give to the body its general form and proportion. 3. Physical exercise in Schools. Its practical impor- tance and value in promoting the health of young people. 4. Food and drink are the materials necessary to keep up the warmth and growth of the body, and enable it to make its movements. 5. Origin and Nature of Fermented Drinks. Alcoholic liquors described, and their injurious effects upon the bodily life fully discussed. 12 YOUNG folks' PHYSIOLOGY 6. Digestion is the process of changing the food into a condition suitable for absorption into the blood. 7. The blood is the vital fluid of the body. The course of the blood through the body is called its cir- culation. 8. Bespiration is the act of breathing. It is carried on mainly by the lungs. 9. The skin, or the outer covering of the body. 10. The nervous system enables us to move, see, feel, taste, and so on. The brain and the spinal cord are its central organs. 11. The special senses enable us to touch, taste, smell, hear, and see. We often speak of them as the five senses, or the five gateways of knowledge. 12. Excretion is the process by which the body gets rid of its waste matters, mainly through the lungs, skin, and kidneys. 13. The throat and Toice described. THE BONY FRAMEWORK 1 3 CHAPTER II THE BONY FRAMEWORK 10. The Skeleton. — Every animal must have some kind of a framework or support to give its body form or shape. This framework in most animals is a sup- port made up of a number of firm and hard substances called bones. The bones may be on the outside, like a coat of mail, as seen in the lobster and turtle ; or there may be a framework of those inside of the body, moved by mus- cles outside, as seen in the codfish and shad. In fact, all animals that belong to the great backbone family have an inside framework. This bony support is called the skeleton, meaning a "dried up body." It is to the body what the ribs are to a vessel, or what the frame is to a house. Every one is familiar with the picture of the human skeleton. It shows us how the dead bones of the human body look when taken out, cleaned, and held by wires in their proper places. The human skeleton is made up of about two hundred separate bones,^ of various sizes and shapes. 1 To be more exact, 28 bones are counted in the head, including the three bones in each ear, 54 in the trunlc, and 124 in the limbs. This number depends upon the time and how the bones are counted. The 32 teeth are not usually reckoned as bones. Several bones, which in youth are made up of separate pieces, unite in old age, and make one bone. The breast- bone, for instance, in the child, consists of eight pieces ; but in adult life it is made up of only three. 14 YOUNG folks' physiology The bones of the body thus arranged give firmness, strength, and protection to the soft tissues and vital organs, and form, as it were, the foundation upon which our bodies are securely built. II. How Bone is made up. — -Bone is a hard and strong substance, made up of animal matter united with certain mineral earths, as lime and potash. The earthy part of bone makes up about two-thirds of its weight, and the animal portion the other third. Put a slender chicken bone in a mixture of two ounces of muriatic acid and one pint of water, and let it soak for two or three days, and the earthy part will be dissolved, leaving only the animal matter. The form of the bone is kept ; but it can be easily bent, cut, torn, or even tied into a knot. Again, put a soup-bone into a hot fire, and let it burn for two or three hours. Take it out carefully, and, while the shape is still kept, the bone is brittle, and will readily crumble when pinched between the fingers. The animal part has been burned out, and only the white bone-earth is left. The lime gives hardness and firmness to the boiies ; while the animal substance makes them elastic, tough, and flexible. The proportion varies with age. In childhood the bones have more animal matter than earthy: hence a child's break easily, and, when broken, soon Fig. 6 The outer bone of the leg, tied into a knot, after the hard mineral matter has been dissolved out by acid. bones do not THE BONY FRAMEWORK 15 knit together. In old age, there is more lime in the bones than animal matter : hence they are brittle, and easily broken. They unite slowly, and sometimes not at all. 12. General Structure of the Bones. — If we take a long bone, like that from a sheep's leg, or even a part of a beef shin-bone, and saw it lengthwise, we see that Fia. 7. — A thin slice of bone, cut crosswise, as seen under the microscope. the ends are soft and spongy, while the shaft is hard and compact. It is hollow, and the central cavity runs almost the whole length of the bone. It is filled, in life, with a soft substance called marrow. If the bones were solid, they would be much too heavy for ordinary use. A bone may be hard as a rock on the outside, on account of its thin, dense layer of compact bony tissue, and yet be light because of its cavity and the trellis-work of loose, spongy texture at the ends. l6 YOUNG folks' physiology Bones are of many different shapes, according to the uses to which they are put. Some are long, with hollow shafts, as the bones of the arm and leg ; others are short, to give strength, as the bones of the fingers and toes ; some are flat, for protection, and to cover cavities, like the bones of the skull and shoulder-blades ; while others are of various odd shapes, and hence called irregular, as the bones of the backbone and ankle. 13. Minute Structure of Bones. — When bones are alive or fresh, they have a pinkish-white color, caused by the blood which flows through every part of them. Take a long, slender bone, like a rib or a sheep's leg, and we find that it is elastic, and will bend. Now, if we scrape down on the bone with a sharp knife, we find that it is wrapped round with a tough but very thin covering, called the periosteum, meaning Power of Bone to resist Decay. — "The power of bone to resist decay is remarkable. Fossil bones deposited in the ground long before the appearance of man upon the earth have been found to exhibit a con- siderable portion of cartilage. The jaw of the Cambridge Mastodon contained over forty per cent of animal matter — enough to make a good glue — and others about the same. From this we see that a nutritious soup might be made from the bones of animals that lived before the creation of man. The teeth resemble bone in their structure, but resist decay longer; they are brought up by deep-sea dredging, when all other parts of the animal have wasted away. The bones differ at different ages, and under different social conditions. In the disease called ' rickets,' quite common among the ill-fed children of the poor in Europe, but somewhat rare in America, there is an inadequate deposit of the mineral substance, rendering the bones so flexible that they may be bent almost like wax. Exercise is as necessary to the strength of bone as to the strength of muscle ; if a limb be disused, from paralysis or long sick- ness, the bones lose in weight and strength as well as the soft parts. Bone is said to be twice as strong as oak, and, to crush a cubic inch of it, a pressure equal to 5,000 pounds is requisite." THE BONY FRAMEWORK 17 "about a bone." All bones are covered with perios- teum except where they go to form a joint. They would die if this covering were for any cause removed. Bones have a great number of blood-vessels, which, becoming very small and hair-like, pass through tiny holes, or tubes, in the bones, and bring materials for their nourishment and growth. The tiny tubes called "canals," through which the blood- vessels of the bones travel, can be seen only with a microscope. Round these tubes the bony matter is arranged in layers, and between these layers are small cavities. These cavities are joined to each other, and to the canal which they surround, by other extremely fine tubes. As seen under the microscope, the appearance is not unlike a small animal with a great many legs. Thus the bones are tunnelled, like honey-comb, with passages through which the blood — " the river of life " — flows in every direction. (Fig. 7.) Fig. 8. — Cross Section of Bone, highly magnified; the Canals are left white. THE HEAD. 14. The Head. — The skeleton, or bony framework of the "house we live in," consists of the bones of the head, the trunk, and the extremities. The bones of the head include those of the cranium and those of the face. Together they form the strong box of bone commonly called the skull. x83 YOUNG folks' physiology tftVISlS OSBVIBW SCAPULA MBBSK" JEBTEBr./E THE BONY FRAMEWORK 1 9 The general shape of the head is that of an arch. The arch is the strongest shape in which the skull could be made, just as the arched bridge is the strong- est-shaped bridge which can be made to bear the heavy loads that have to pass over it. 15. The Cranium. — The Cranium, or brain-case, is a kind of oval, bony shell, which holds and protects the Fig. 10. — The Skull. brain. It is made up of eight bones closely locked together by seams or sutures, somewhat like the dove- tailing used by carpenters. Let us arrange and de- scribe these eight bones thus : — One Frontal (forehead). One Occipital (back of head). Two Parietal (side of head). One Sphenoid (wedge-shaped). Two Temporal (temples). One Ethmoid (sieve-ltke). 20 YOUNG FOLKS PHYSIOLOGY The frontal bone forms the forehead. It is this bone which gives a beauty of form and a dignity of person seen in no other animal in creation. Two bones make the sides, or walls, of the head. They are called the parietal bones, from a Latin word meaning a wall. They join the two temporal bones,' which lie round each ear, and form the " temples." The occipital bone forms the lower and back part of the skull. This- broad, flat bone rests on the topmost bone of the backborre, and is pierced by a large hole through which a long cord of whitish marrow, called the spinal cord, passes from the brain-case into the spinal canal, and runs down the whole length of the backbone. The sphenoid, or wedge bone, is wedged in between the bones of the cranium and those of the face, and serves to lock together fourteen of these bones. The ethmoid, or sieve-like bone, so called because it is full of holes, like a sieve, lies between the eye-cavities just at the root of the nose. The nerves of smell pass through the holes in this bone into the cavities of the nose. 16. The Face. — All the bones of the face, except the lower jaw-bone, are firmly fixed to each other, and to the bones of the cranium. By their union, these bones form five cavities ; namely, the two large cup-like cavities called the orbits, the two nostrils, and the mouth. The orbits are hollow, bony sockets in which the eyes are placed. In the back part of each cavity is .a crevice through which the nerve of sight (optic nerve) passes from the brain to the eye. THE BONY FRAMEWORK 21 The face contains fourteen bones ; viz., — Two Malar (or cheek) bones. Two Palate bones. Two Nasal (or nose) bones. Two Lachrymal bones. Two upper Jaw-bones (upper One Vomer (ploughshare) bone. maxillary). Two Turbinated (spongy) bones. One Lower Jaw-bone (lower max- illary). Under the orbits, and overlapping the jaw-bones, we find the two malar, or cheek bones, which in some races, as the American Indians, are very prominent. The two bones that form the upper part, or bridge, of the nose, are called nasal bones. The lower part of the nose is gristle, and not bone. Next we come to the two upper jaw-bones, containing, as we all know, some of our teeth. The rest of the teeth are fixed in the lower jaw-bone, which moves by means of a hinge-joint, so as to allow the opening and shutting of the mouth. The remaining bones of the face are small. Two bones, forming the back part of the roof of the mouth, are called the palate bones. Two little bones, partly forming the inside walls of the eye-cavities, are called the lachrymal bones, from a Latin word meaning a tear. There is, through each of them, a canal which carries the tears from the eyes to the nose. The vomer, or ploughshare bone (so called from its resemblance to the share of the farmer's plough), is situ- ated between the nostrils. Two delicate little bones within the nose-cavity, shaped like a scroll or horn, are called turbinated bones, from a Latin word meaning a whirl. 22 YOUi\G FOLKS PHYSIOLOGY 17. How the Bones of the Head are joined to- gether. — The bones of the head are joined together in a peculiar way. The edges of the bones of the cranium and face are shaped somewhat like the teeth of a saw. In adults, these edges fit into each other, and grow together, resembling the dovetailed joints in a cabinet- maker's work : hence they are called sutures, from a Latin word which means a sewing or a seam. In infancy all of the bones of the skull do not meet, and the throbbing of the brain at the top of the head is easily seen. These openings are called fontanelles, "little fountains." The bones of the skull are not wholly welded together till the child reaches adult life. When the bones are knitted together, these sutures add greatly to the strength and resistance of the brain-case. THE TRUNK. 18. The Trunk. — The trunk is that part of the body which supports the head, and to which the arms and legs are attached. It has two important rooms, or cavities. The upper one, called the thorax, or chest, consists of a bony framework formed by the breast-bone, ribs, and backbone. It contains the lungs, with- which we breathe; and the heart, which pumps the blood through the body. The lower part, or abdomen, holds the stomach, liver, bowels, kidneys, and other important organs. Between the chest and abdomen is stretched a broad muscle, which moves up and down as we breathe. THE BONY FRAMEWORK 23 This is called the "midriff" by the butchers, or dia- phram, from a word meaning a fence or a partition. The principal bones of the trunk consist of those of the spine, ribs, and the Iiips. There are fifty-four bones in the trnnk, and they are thus arranged : — ■ /. Ths Spine contains 28 sepa rate bones 7 Cem'cei (or neck) Vertebras. 12 Dorsal (or back) Vertebras. 5 Lumbar (loins) Vertebra. I Sacrum, or sacred bone. / Coccyx, or cuckoo-bone. S7 True Ribs. 3 False Ribs. III. I Sternum, or breast-bone. IV. The 2 Hip-bones. V. The Hyoid bone. 2 Floating Ribs. ig. The Spine. — The spine, or backbone, serves as a support for the whole body. It is made up of a number of separate bones called vertebra, between which are placed pads, or cushions, of gristle. These cushions are elastic ^ or springy, yet thick and strong. They serve to break the force of any shock or injury which the spine may receive, just as the springs of a carriage lessen the jolting which would be felt without them. These soft pads also prevent any grat- ing or friction of one bone on another. They are also yielding ; that is, are readily pressed together, else the backbone could not bend.^ 1 The elasticity of these plates of cartilage is so great, that we are actually about half an inch shorter when we go to bed than we were when we got up in the morn- ing, by reason of their flattening out under the weight of the erect position. 2 These bones, again, are prevented from yielding too much by strong tough straps, or ligaments, which stretch between them. If the separate bones were allowed too much freedom of movement, the spinal cord inside the canal would be crushed or twisted, and paralysis or death would at once follow. 24 YOUNG FOLKS PHYSIOLOGY The spine is really a pile of twenty-four separate bones, resting on and above a strong, three-sided bone called the sacrum, or sacred bone, which is wedged in between the hip-bones. The sacrum, although reckoned as one bone, actually consists of five distinct ver- tebrae, which grow together, however, and form a single bone in adult age. Joined to the lower end of the sacrum is a little, tapering bone called the coccyx, so named from its resem- blance to the beak of a cuckoo. The whole spine forms a pillar, or column, of bones, tapering as it goes up. At the top are seven cervical or neck vertebrae : below them are the twelve dorsal or back vertebrae, from which spring the ribs. The five low- est bones, called the biinbar, or loin vertebrae, are the thickest and largest. Each vertebra of the backbone is pierced with a hole through its centre ; and the separate bones are so placed one above the other, that these holes form a continuous tube, or canal, down which passes the spinal cord.^ Fig. II. — TheBackbone. 1 Imagine a number of spools placed one on another. The central hole through each would be exactly over the other, and there would be one long tube, or channel, through the whole string of spools. This is somewhat like the arrangement of the vertebrffi of the backbone. THE BONY FRAMEWORK 25 In this bony canal the spinal marrow lies protected from injury. From each vertebra project spines, or thorns, of bones, to which are fastened muscles, which keep the flexible backbone erect, and lift the head and shoulders. The row of spines along the whole length of the backbone forms a ridge, which we can feel by press- ing with the fingers up and down the middle of the back. The spine is one of the most curious and wonderful things in nature, — so firm, and yet so elastic ; so stiff that it will bear a heavy weight, and yet bending like rubber ; a tapering pile of odd-shaped bones, so admira- bly planned, and so wonderfully put together, that the delicate brain resting upon it, and the spinal cord hidden within its bony canal, are not often hurt. The most daring athlete rarely breaks the bones of his spine, or puts them out of place. 20. The Ribs. — The ribs are the slender, but strong, bony hoops which help make the framework of the chest. * They pass around the chest, and strengthen it, resembling somewhat the hoops of a barrel. There are twenty- four ribs, — twelve on each side. The ribs are joined to the backbone behind, and in front to a flat, narrow bone, shaped somewhat like Fig. 12. — The Ribs and Sternum. 26 YOUNG folks' PHYSIOLOGY an ancient sword or dagger, called the sternum, or breast- bone. This bone does not go down far enough to allow of all the ribs being joined directly to it. Only the four- teen upper ribs — that is, seven on each side — are thus fastened : they are on this account called the true ribs. The next six ribs, three on each side, come partly round from the spine, and then each is joined by gristle to the one above it. They are called \h& false ribs. The remaining four ribs, two on each side, spring from the spine, like their neighbors, but are not fastened to any- thing in front, and for this reason are called the. floating ribs. The spaces between the ribs are filled with strong muscles, one set of which raises the ribs, the other lowers them. This barrel-shaped framework of bones that makes the chest, although strong, is not rigid. It can be raised and lowered, owing to the joints at the back, the cartilages, or gristle, in front, and the muscles between. The space within thus becomes larger, and more room is allowed for the action of the heart and lungs. How the Skull and the Spine are joined together. — The skull and the spine are joined in a peculiar manner. The first, or topmost, of the neck vertebrae is called the atlas, so called from the tabled Atlas of the ancients. In olden times, people believed that the earth was supported on the shoulders of a huge giant called Atlas. As, therefore, the head is supported by this bone, it received the name of atlas, after the fabled giant of old. On the lower part of the skull are two smooth rockers, which fit into two little smooth grooves hollowed out in the atlas. We are thus able to rock the head to and fro. The second vertebra of the neck is called the axis, and has a peg, called the odontoid process, or tooth-like peg, which fits into a notch in the atlas. Thus, when we turn the head sideways, the atlas turns around the peg of the axis. THE BONY FRAMEWORK 2/ 21. The Hips. — The lower part of the trunk is formed by two large, irregular bones, very firm and strong, called the hip or haunch bones. They join the Fig. 13. —The Pelvis. sacrum behind, and each other in front. The two hip- bones, with the sacrum and coccyx, form a kind of bony basin called the pelvis, in which many important organs are held. Each hip-bone has a deep, cup-shaped cavity, or socket, into which the rpunded head of the thigh-bone fits. The Hyoid Bone. — Under the lower jaw is a little horseshoe-shaped bone called the hyoid bone because it is. shaped like the Greek letter v. The root of the tongue is fastened to its bend, and the larynx is hung from it as from a hook. The hyoid, like the knee-pan, is not connected with any other bone. THE UPPER LIMBS. 22. The upper Limbs. — Man has two upper and two lower limbs. Each upper limb consists of three parts, the upper arm, the fore-arm, and the hand. Each 28 YOUNG folks' physiology lower limb also consists of three parts, — the thigh, the lower leg, and the foot. In speaking of the bones of the upper extremities, however, it is usual to include the two shoulder-blades and the two collar-bones. Each upper limb, therefore, contains the following bones : — ( Scapula, or shoulder-blade. Upper arm ....;..■] Clavicle, or collar-bone. ( Humerus. ( Ulna. Foi^e-arm | ^^^y/^^ !8 Carpal (wrist) bones. 5 Metacarpal bones. 14 Phalanges, or finger-bones. Making thirty-two bones in all. 23. The Upper Arm. — There are two bones in the shoulder, and they serve to fasten the arm to the trunk. These are the scapula, or shoulder-blade, and the clavicle, or collar-bone. The shoulder-blade is a large, flat, three-sided bone, which is placed on the upper and back part of the chest, outside of the ribs. On the outer side it has a saucer-like cavity into which the rounded head of the arm- bone fits. The collar-bone has a double curve like the Itahc letter/. It lies across the shoulder, like a kind of rigid bar, over and above the first rib. It serves, like the keystone of an arch, to keep the shoulders apart, and to hold. them firm when the upper limbs are used. Its Fig. 14. — Back of Right Shoulder-Blade, THE BONY FRAMEWORK 29 inner end is tied to the breast-bone, and its outer to the shoulder-blade. The hnmerus is the long, hollow bone of the upper arm. It fits into the socket of the shoulder-blade, and goes to the elbow, where it is joined to the two bones of the fore-arm. 24. The Fore-arm. — The fore-arm contains two long, hollow bones, the nlna and the radins. The ulna is the larger of these two bones, and is joined to the humerus by a hinge-joint at the elbow. It is prevented from moving too far back by a process, or projection, which makes the sharp point of the elbow. The radius is the long, slightly curved outer bone "of the fore-arm. It is smaller than the ulna. Its upper end is fastened both to the ulna and the humerus. Its lower end is much larger than its upper, and carries the hand. The radius is tied to the ulna in such a manner that it can glide nearly round it. This gives us the power of twisting the fore-arm and hand. 25. The Hand. — The hand consists of three parts, the wrist, the palm, and the fingers, containing in all twenty-seven bones. There are eight carpal, or wrist bones, all of which are very closely packed in two rows, and bound together with cords. The wrist is thus as strong as if made of a single bone, while at the same time it is capable of the most delicate movements. The metacarpal bones are the five long bones which form the palm of the hand. They are attached to the carpal bones of the wrist, and to the bones of the fingers. 30 YOUNG FOLKS PHYSIOLOGY The phalanges of the fingers are the fourteen small bones which are tied end to end, to form the fingers. Each finger has three bones, each thumb two. The bones of the fingers are arranged in three rows, as will be seen by closing the hand. The wrist-bones, metacarpal bones, and finger-bones are all held in place by strong but flexible ligaments. By this beautiful contrivance, the greatest strength and Fig. 15. — Boues of Right Hand. elasticity are given to the hand, which is thus fitted for all kinds of work, from grasping heavy hammers to handling the pen, and threading the finest needle. THE LOWER LIMBS. 26. The Lower Limbs. — The general structure and number of the bones of the legs bear a striking similarity to those of the arms. Thus the leg, like the arm, consists of three parts, the thigh, the lower leg, and the foot. THE BONY FRAMEWORK 3 1 There is only one bone in the thigh, while there are two in the lower leg. We see that this is a similar plan to that of the arm. In the foot, the tarsal or ankle bones correspond to the carpal bones of the wrist ; while the metatarsal bones and the phalanges of the foot take the place of the metacarpal bones and the phalanges of the hand. The bones of the leg are, — Thigh Femur, or thigh-bone. ( Patella, or knee-pan. Lower leg < Tibia, or shin-bone. ( Fibula, or splint-bone. ( 7 Tarsal, or ankle-bones. Foot 1 '^ Metatarsal, or instep-bones. ( 14 Phalanges, or toe-bones. Making thirty bones in all. 27. The Thigh The top bone of the leg is the femur, or thigh-bone. It is the largest and strongest bone of the body. It has a rounded head, which fits into a cup-like cavity in the hip-bone. At the knee- joint the thigh-bone meets the bones of the lower leg, to which it is fastened by strong cords. 28. The Lower Leg. — The lower leg consists, like the fore-arm, of two bones. The larger, a strong, three-sided bone, with a sharp edge in front, is called the tibia, and is commonly known as the shin-bone. The smaller bone, bound at both ends to the tibia, is called the fibula, meaning a clasp. It is a long, slender bone on the outside of the leg, and its lower end forms the outer ankle. It is often spoken of as the small bone of the leg. Covering in part the knee-joint is a flat, three-sided bone, called the patella, or knee-pan, which protects the joint, and gives firmness to the leg. 32 YOUNG FOLKS' PHYSIOLOGY 29. The Foot. — The foot, like the hand, consists of three parts, the bones of which are known as the tarsal bones, the metatarsal, and the phalanges of. the foot. The tarsal, or ankle-bones, are seven in number, and form the heel, the ankle, and part of the sole of the foot. These seven irregular bones a.re tied firmly together by straps, or ligaments, and are strong enough to bear the weight of the body. The large bone, SPBMIHQ TOIS V TARSAL BSNES FORMINQ ANKLE E HETATARSAL fiONES ASTRASALUa HEEL-BOHS Fig. 16. — Bones of Foot and Ankle. which projects backwards, is the heel-bone ; and on the bone over this the shin-bone rests. The heel-bone is connected with the great muscles of the calf of the leg by a very strong cord, or tendon, called the tendon of Achilles.i 1 The warlike deeds of this famous Greek hero were sung by Homer. Ac- cording to the story, Achilles received his death-wound in the heel, no other part of his body being vulnerable. THE BONY FRAMEWORK 33 The metatarsal bones, like the palm of the hand, are five in number, and form the instep of the foot. They are the connecting link between the ankle-bones and the phalanges of the foot. The bones of the toes, or phalanges, number fourteen in all, three in each toe, with the exception of the great toe, which, like the thumb, has only two bones. 30. Use of the Bones. — Bones serve many useful purposes. They keep up the general shape of the body. The skeleton, as we have seen, is its framework. It gives strength and support to the soft and fleshy parts. If there were no bones, and the whole body were a mass of flesh only, the legs would give way, and finally be crushed down, under the great weight of the body. Again, bones protect the soft organs which lie be- neath them. The bones of the head protect the soft and delicate brain in a complete box of bone : the ribs The Hand and Foot compared. — The toes and fingers correspond exactly in their number and the character of their bones, the great toe holding the same place in the foot as the thumb does in the hand. In the hand the wrist-bones are small and the finger-bones long and slender. The thumb is made to move in the opposite direction to the fingers, and thus the hand becomes adapted for grasping purposes. Indeed, the hand may be either a most delicate pincer or a powerful vise, while its flexi- bility and rapidity of motion can nowhere be better seen than in the rapid movements of the skilful musician on the keyboard of the piano or organ. Now look at the bones of the foot. The ankle-bones have a clumsy look, and all the hollow bones are short, thick, and heavily jointed. It is at once clear that strength, and not flexibility, is the object of these bones. The feet, which are to support the entire weight of the body, are thus better adapted to do their work than they would be if built of slender, long bones like those of the hand. 34 YOUNG folks' physiology protect the heart and lungs in a large cage of bone, and so on. Passage-ways and little cavities are hol- lowed out of solid bone to lodge and shield important organs. Grooves and canals are formed in the hard bone to receive and protect tender organs, delicate nerves, and tiny blood-vessels. Finally, the surfaces of bones are fitted with grooves, knobs, and sharp edges, to which muscles are tied. We are thus enabled to stand erect, and make with ease and quickness the countless movements of the body. The blood filters through bone as freely as it does through any other living tissue. The bone-structure is ever changing. Old material is got rid of, and new matter takes its place. 31. Repair of the Bones. — When a bone is broken, blood trickles out between the injured parts, and after- ward gives place to a sticky, watery fluid, which grad- ually becomes thicker, like sirup or jelly. This slowly . hardens into a new bone-structure, and forms a kind of cement to hold together the broken ends. Nature does not spare her healing-cement. The excess bulges out around the place of union, over which a bunch is felt, for a lifetime perhaps, under the skin. In young people, a broken bone will knit together in two or three weeks ; while in grown-up people six weeks or more will be required. In aged persons, a broken bone may cripple them for life. It is then a tedious matter, and sometimes the bones will not unite at all. After a bone has been once broken, it is fragile for some time ; and great care should be taken lest it be THE BONY FRAMEWORK 35 broken a second time before it firmly unites. When a bone is broken, the ends tend "to ride" over each other, because the muscles pull the broken portions apart ; hence the need "to set" the bone by drawing the injured' bone into place, and keeping it so by splints and ban- dages, properly applied by a surgeon. 32. How Bones are joined tbgether. — The place where two bones join together is called a joint. Joints vary according to the kind and amount of motion. Get a knuckle of ham, mutton, or a beef-joint at the market. Cut into it, open up the joint, and study its structure. In all joints, the essential parts are the same. The ends of the bones are shaped according to the special Fig. 17.— The Right Knee-joint, showing how 1 . . firmly it is bound about by ligaments. needs of each joint. The joint-end of the bones is smooth, moist, and tipped with a thin layer of gristle, or cartilage. This smooth and glistening covering is bathed by a sticky Missing Page Missing Page 38 YOUNG FOLKS PHYSIOLOGY completely shut it up in a bag. This prevents the bones from being easily dislocated, or slipped out of place. It is a difficult matter to carve a turkey or a fowl, because one has to cut through these ligaments before he can cut the limbs apart to serve it out in pieces. There is the same diffi- culty in separating the two bones in a shoulder or leg of mutton, be- cause they are held firmly together by strong ligaments. 34. Hints about the Health of Bones. — The tones of children are flexible, and capable of being bent by long-con- tinued strain; because there is more animal matter than in later years. Therefore great care must be taken with the positions which children take at home, Fig. 19. — A School-girl sitting at her Desk in a r, i j i t. position often resulting in Curvature' of Spine. 3-t SCh00l,and ClSCWhere. Allow a child to walk too early, before the legs are strong enough to bear the weight of the body, and " bow-legs " result. At school, the desks should not be too low, thus causing a forward stoop ; or too high, thereby throwing THE BONY FRAMEWORK 39 one shoulder up too much, and giving a twist to the spine. If the seats are too high, the feet have no sup- port, and injury to the thigh may result. If too low, there is undue strain on the shoulder and backbone. Round shoulders and curvature of the spine may result from long-continued positions of this kind. The feet should rest firmly on the floor, and the edge of the desk should be about one inch higher than the level of the elbows. A line dropped from the edge of the desk should strike the edge of the seat. Three sizes of desks, should be used in every schoolroom, and more in ungraded schools. Seats should be regu- lated according to the size of the pupil, and frequent changes of seats should be made. or r Fig. 20. — A correct Position at the School-desk, not get into the habit with no undue strain on the Splne. of taking hurtful posi- tions, such as sliding down into the seat, sitting on the foot, or on the small of the back. Bending over too much while reading, writing, sewing, or otherwise at work, is apt to cause spinal curvature and round shoulders. 40 YOUNG FOLKS PHYSIOLOGY The prevailing fashion of using tight and high-heeled boots and shoes cannot be too strongly condemned as both hurtful and ugly. High heels throw the weight of the body forwards, and force the foot down on to the toes. This will in time not only crowd all shape out of the toes, causing tender feet, corns, bunions, distorted joints, and in-growing nails, but makes the natural gait stiff and ungainly. 35. Effect of Alcohol and Tobacco on the Bones. — Since the bones constitute the framework of the body, a person's form depends upon the size and shape of his bon«s. The bones grow during childhood and youth; whatever growth one loses during that time cannot be afterward made up. It is the testimony of sagacious physicians that alcholic drinks and tobacco tend to check the growth of the bones. The smoking of cigarettes is especially h-urtful to growing boys, because such a habit tends, besides other harmful things, to dwarf the growth of the bones. A well-developed form is something to be prized. No wise boy or girl will risk attaining it by indulging in filthy or injurious habits while young. See Note i, page 355. THE BONY FRAMEWORK 41 I. Cranium (8 bones) f 1 FronUl(forehead), 2 Parietal (side o£ head), 2 Temporal (temples), 1 OccipitaKbackofhead), 1 Sphenoid (wedge-shaped), I 1 Ethmoid (sieveJike). Si KM , 00 W ,2. K H II. Face (14 bones) f 2 Malar (cheek), 2 Nasal (nose), 2 Upper Jaw-bones, t Lower Jaw-bone, 2 Palate bones, 2 Lachrymal bones. 1 Vomer (plough-share} bone, 2 Turbinated (spongy) bones. III. The Ear (6 bones) . Hammer, Anvil, Stiirup, I. Spinal Column (26 bones) 7 Cervical (neck) Vertebra, 12 Dorsal (back) Vertebrae, 5 Lumbar (loins) Vertebra, Sacrum (sacred bone), Coccyx (cuckoo-bone). != 'a w S II. The Ribs (24 bones) . 7 True Ribs, 3 False Ribs, r III. Sternum (breast-bone). IV. Two Hip-bones. V. HvoiD Bone. Upper Arm Scapula (shoulder-blade). Clavicle (collar-bone), Humerus (arm-bone). !3 i FOKE-ARM . . . Ulna (fore-arm), Radius (spoke-bone). Hand ' 8 Carpal (wrist) bones, 5 Metacarpal (palm) bones, 14 Phalanges (fingers). m Thigh Femur (thigh-bone). Lower Leg Patella (knee-pan), Tibia (shin-bone), Fibula (splint-bone). S Foot 7 Tarsal (ankle) bones, 5 IIAetatarsal (instep) bones, 14 Phalanges (toes). 42 THE MUSCLES CHAPTER III THE MUSCLES 36. The Muscles. — The smallest child or the tiniest insect can move its own limbs when it pleases, but the largest vegetable and the sturdiest tree never move except some cause outside of themselves acts upon them. Movement in man is made by muscles. The limbs are moved by muscles. Even the motions of the stomach and the action of the heart are controlled by muscles. Muscles move the skin. In many animals this action is well marked, as when the horse shakes his hide to get rid of biting flies. Muscles move the bones, the fingers, and toes, the mouth, and the eyelids. In brief, all motion in the body is dependent upon them. 37. The Structure of Muscle. — Muscle is simply the lean meat, or flesh, of the body. When we eat beef- steak or lean mutton for dinner, we are eating mus- cle. Muscles are made up of bundles of fleshy strings called fibres held together by a very thin web of tis- sue, not unlike the thinnest of tissue paper. Each fibre Fig. 21. — A Muscular Bundle teased out to show its Fibres. THE MUSCLES 43 Fig. 22. — a Fibre oJ Muscle, showing the separate Disks of which it is composed at a and b. is made up of a great many smaller fibres, called fibrils, held together in the same way. Each fibril consists of rows of little cells, arranged like a string of beads. This gives the muscles a peculiar striped look un- der the microscope, which marks the ordinary mus- cles of the body. When corned beef has been " boiled to rags," as we say, the web of connecting tissue is partly dissolved by heat, and the fibres are plainly seen. 38. How Muscles act. — Muscles have a peculiar power of their own. This is the power to contract, or to shorten themselves. In order for a muscle to act, it must be .stimulated. This stimulus, or that which gives it the power to act, is the nerve-force flowing through the nerves distributed to the muscles. Contraction is not, how- ever, the natural state of a muscle. After a longer or shorter time, it is tired, and begins to relax. Even the heart, the hardest- working muscle of the body, pumping blood night and day all the days of our life, has a short time to rest between its beats. Fig. 23. — Portions of the Muscular Fibre highly maguiiied. 44 YOUNG folks' physiology. Fig. 24 — Principal Muscles of the Front of the Body. THE MUSCLES 45 39. Kinds of Muscles. — Muscles are of two kinds, voluntary and involuntary. Voluntary muscles are those which can be made to act under the influence of the will. Such muscles make up the bulk of the fleshy parts of the body, and form a covering for the bony skeleton. The involuntary muscles are those which carry on their work without the use of the will — -indeed, we can- not prevent them acting. Among these muscles may be mentioned those of the stomach, the bowels, the lungs, and the heart. When they contract, they force along the contents of these organs. In this way the blood is forced out of the heart, the food out of the stomach, and so on. If these muscles were not entirely independent of the will, they would cease to act the moment we fell asleep, and death would be the result. Hence these muscles continue to work at all times, because the will has no power over them. 40. Arrangement of Muscles. — The muscles are arranged, for the most part, so as to oppose each other in action. Thus, when one set produces motion in one direction, there is, opposite to it, another group of mus- cles, which draws the part moved back into place again. When a piece of lean meat is brought from the market, it looks like a solid mass of flesh. It really con- sists of parts of several distinct muscles. Each of these muscles, when separated, will have the following form : — A middle or thick part. Two tapering en^s, one attached to a fixed bone, and called the origin; the other connected with a movable bone, and called the insertion of the muscle. These tapering ends 46 YOUNG folks' physiology are attached, or tied, to the bones by means of sinews, or tendons. As a muscle acts only by contracting, each movable bone must be supplied with at least two opposing mus- cles. One of these contracts, and draws up the limb : this is called a flexor muscle. The other, on the oppo- site side, by contracting, stretches out the limb : this is called an extensor muscle. Take, for instance, the two main muscles of the arm. When we bend the arm, we notice that the muscle in front of the upper arm swells up, and becomes hard. This is the biceps, or two-headed muscle, which has con- tracted in obedience to the will, and by its contraction has drawn up the fore-arm. When we wish to straighten the arm, we do not merely relax this muscle ; for, if we Fig. 25. — Biceps and Triceps Muscles. did, the arm would simply fall into the straight position. A muscle at the back of the upper arm, called the tri- ceps, the three-headed muscle, now contracts in obedi- ence to the will, and by its contraction straightens the muscle. THE MUSCLES 47 41. The Tendons. — If we bend the leg or arm, and grasp the inside bend of the joint with the hand, we feel the motion of cords just beneath the skin. These are the tendons, or sinews, forming the tapering ends of muscles, which are fastened to the bone. Tendons are white, glistening cords, like belts or straps, which connect the muscles with the bones. They Fig. 26. — Muscles and Tendons of the Hand. are very strong, but flexible. Children often amuse themselves by taking the leg of a fowl, a rabbit, or some small animal, and moving the toes by pulling a white cord in the leg. This cord is a tendon. Tendons are most numerous about the joints, especially the larger ones, like the knee and elbow. They save a great deal of space, and allow great freedom of movement, where muscles large enough to do the work would be exceed- ingly bulky and clumsy. 48 YOUNG folks' physiology The longest..and strongest tendon in the body is the tendon of Achilles. The tendons of the muscles which bend the knee, and are felt in the bend of the joint, are commonly called the "hamstrings." Fig. 27. — Muscles of the Face and Neck. 42. TheBony Levers of the Body. — The word "lever" means simply a rigid bar, or rod, which moves about a certain fixed point, called the fulcrum. We have all seen a man trying to raise a heavy stone with a crowbar. He places one end of the bar under the stone, and THE MUSCLES 49 presses down the other end. In this case, the bar is the lever, and the ground under the bar the fulcrum. The pressure which the man applies is called the power, and the stone to be lifted is called the weight. We have the same thing in a seesaw, where the plank is the lever, and the block on which it rests, the ful- crum ; while the power and weight are first at one end, and then at the other. In a lever, then, we have three things to consider, — the fulcrum, the power, and the weight. Levers are divided into different classes, according to the position of these three things. (i) First Class. — Levers of this class have the ful- crum in the middle. (2) Second Class. — In this class, the fulcrum is at one end, the power at the other, and the weight in the middle. (3) Third Class. — In this class, the fulcrum is at one end, the weight at the other, and the power between them. In the various movements of the body, we have instances of all three kinds of levers. The skull, as it nods backwards and forwards upon the atlas, is an instance of the first class of levers. It is like the seesaw we have just spoken of. The skull rests on the spinal column, which is the fulcrum ; the muscle at the back of the neck is the power, and the front part of the skull is the weight. We have all seen a woman running a sewing-machine with her feet. In this case, the ankle-joint is the fulcrum ; the tendon of Achilles, attached to the heel-bone, is the power; and the weight is at the toes. so Fig. 28. YOUNG folks' physiology This is another instance of the first class of levers. When we stand on tiptoe, the power re- quired to raise the body is ap- plied to the heel-bone by its stout tendon. The toes are the ful- crum, and the bones of the foot support the weight. We have in this case a lever of the second class. The third class of levers is the one which occurs most frequent- ly in the body. Of this we have an example when we bend the fore-arm. The elbow is the ful- crum, the fore-arm and hand are the weight, and the biceps mus- cle, at its insertion in the radius, is the power which is thus placed between the weight and the ful- crum. 43. A Few Important Muscles. — There are about five hundred muscles in the human body, all necessary for performing the va- rious movements and operations of this complicated machine, — our body. There are about fifty in each arm and hand. Six little muscles move each eye- ball. THE MUSCLES 51 Muscles are of all kinds of shapes, — round and flat, long and short, fan-shaped, etc., — suited to the work they are to do. Some are large, like the great breast- muscles ; while others are very small, like the tiny mus- cles which move the delicate little bones of the ear. Each muscle has its own name, given to it from its peculiar shape or size, or from the work it has to do.. We chew our food by the help of two strong muscles, called the " chewing-muscles," which move the jaws. They are very large and strong in flesh-eating animals, like the lion and tiger. Turn the head suddenly to one side, and the sharp edge of a long muscle is plainly seen and felt on each side of the neck : one end is tied to the skull, the other to the collar-bone. It acts to turn and brace the head. Inside the cheek is a flat muscle, called the trumpeter's mus- cle. It is largely developed in glass-blowers, and persons who play on wind-instruments. Fig. 29. — Muscles of the Sole of the Foot, first layer. The muscle on each 52 YOUNG FOLKS' PHYSIOLOGY side of the chest is fan-shaped, and powerfully developed in strong men. The large, thick muscle covering the shoulder is thought to resemble the Greek letter ^ (delta). A military officer wears his epaulet over this muscle. The action of the two- headed muscle, which bends the fore-arm, and the three-headed, which straightens it, has been explained. A three- sided muscle covers the shoulder-blade, like a monk's hood, and helps move the shoulder. A very broad muscle in the back is the "climbing- muscle " of the body, and helps pull the arm backwards. Three huge muscles make up the greater por- tion of the fleshy mass in the lower part of the back. They move the thigh backwards, and help keep the body erect. The longest muscle in the body, called the " tailor's mus- cle," runs across the thigh in front. It helps us to cross the legs. Two strong muscles form the largest part of the calf of the leg. The tendons of these two Fig. 30. — Some large Muscles of the Back. THE MUSCLES 53 muscles unite to form the tendon of Achilles. These muscles are used in walking, standing, dancing, and leap- ing. They are of great strength ; because in raising the heel, they have to raise the weight of the body. 44. Effect of Alcohol on the Muscles. — We have learned that it is the nerve-force acting upon the muscles which makes them contract or relax. Now, if we drink more or less of alcoholic liquor, the muscles are acted upon in a peculiar way. The nerve-force that controls the muscles is weakened, and they show a lack of con- trol. The delicate movements which require the long train- ing of certain muscles, as in handling fine tools and Fatty Decay due to Alcohol. — All the important organs of the body have special work of some kind to do, and a peculiar power of doing it. They are made up of various forms of albuminoid matter endowed with living powers which vary with the different tissues. Thus, muscle is made up of fibres which have the power of contraction ; and nerves, of delicate thieads whiph carry nerve impulses. Now, alcohol has the power of changing this vital property of the organs, someway related to albumen, into fatty or oil globules. This we may, for convenience, call fatty decay. Scientific men call it "fatty degeneration." It simply means that fat takes the place of the albumi- noid matter. In brief, there is a decay in the living body of parts of our most important organs. This decay occurs most frequently in the tissues of the heart and liver ; but it may go on in the blood-vessels, in the muscles, in the nerves, and, indeed, in all the vital organs. Alcohol taken for some time often causes this fatty decay. Other poisons, as phosphorus, produce it more rapidly ; but alcohol causes it in a much more general way. The structure of the organs thus diseased is weakened, and their function seriously impaired. The heart, which is composed chiefly of muscle, is very liable to become diseased through the unhealthy accumulation of fat caused by beer-drinking. 54 YOUNG FOLKS PHYSIOLOGY doing gymnastic feats, cannot be made. A person may know the right way of making each movement, and may succeed, after a fashion, in clumsily doing it ; but the trained muscles are no longer wholly under the control of the will. If alcohol enough is drunk, all mus- cular control may be lost, and deep breathing may be the only sign of life. This same lack of control is shown in the act of speech. Each and every word we utter requires special movements of the muscles of the tongue, palate, and throat, all acting in harmony. After drinking alcohol, there is less control of the muscles : the reins are slackened, so to speak ; words may be left out, cut short, or misplaced. According to the stage of intoxication, the words are clipped, stammered, or "mouthed," or "thick," from loss of control of the tongue. The muscles that move the eyes do not act in har- mony : hence the drunken man "sees double." The rapidity with which this loss of control is produced varies with the individual, with the kind of drink, the rate at which it is drunk, and many other circumstances. 45. Effect of Alcohol on Muscular Strength. — People have supposed that alcohol gave them strength for their work, and rested them when they were tired. In both cases this supposition is wrong. Instead of adding to strength or diminishing weariness, it only deadens the nerves and impairs the judgment. For when the strength is tested with a health-lift or other means, the drinker is found to be weaker after taking an alcoholic liquor than before. After the effect of the alcohol has passed off, the feeling THE MUSCLES 55 of weariness is more intense than before, show- ing that the alcohol did not remove it, only con- cealed it. A repetition of the drink may again create insensi- bility to the fatigued feeling, and the muscles may again obey the will ; but only for a briefer time than before. In this way the man who could have put forth just as much strength in an emergency, and could have held out longer, accomplishes less work, abuses his muscles, and deludes his mind by resorting to alcoholic drinks. He has also the injurious effects ofT:he alcohol on other parts of his body to contend with afterward. Physiologists tell us that by the use of the micro- scope in the dissecting-room they find a notable differ- ence between the muscles of the heavy, inactive beer- drinker and those of the total abstainer. The latter are firm, elastic, and of a bright red color. The former are pale, flabby, and often loaded with fat.^ Tiny par- ticles of fat collect in and around the muscle fibres, and crowd upon them, greatly reducing their strength. 46. Effect of Tobacco on the Muscles. — Tobacco causes relaxation of the muscles, and weakens the nerves which control muscular movement. The result is seen in the unsteady hand of the cigarette-smoker when he attempts to draw a straight line or do other nice work which requires precision of touch. And his loose, shuffling gait gives observers the impression that his muscles are too weak to hold his bones together.^ 1 See Note 2, page 356. ' ^ See Note 3, page 358. 56 YOUNG folks' physiology CHAPTER IV PHYSICAL EXERCISE 47. Why we need Physical Exercise. — To be vig- orous and healthy, every organ of the body must be used. Every organ and every tissue must act well its part to be of the_best service. To keep the body in health, it is absolutely necessary that a certain amount of muscular action or physical exercise should be taken every day. The reason for this is plain : the body is made up of certain tissues, such as bone, muscles, and nerves. These tissues consist of a countless number of little cells, as we have learned, every one of which is born, lives its brief moment, then dies, and is cast out as waste or dead matter. The ever-changing blood, in its ceaseless current, brings them their nutriment. The tissues take what is specially suited to their wants, and return as waste matter whatever has become used up. Now, in every tissue, especially in the muscular tissue, this process is hastened by action. Exercise causes more frequent changes in the tissue-cells, and hence an increased flow of blood. The greater the amount of judicious exercise, the greater is the work- ing-power of the individual. Muscular activity is, then, the chief agent in bringing about these wholsome tissue-changes. PHYSICAL EXERCISE 57 Muscles increase in size and strength according to the use made of them. The blacksmith uses vigor- ously the muscles of his right arm day after day, hence their size and strength become well developed. Change his business for that of a clerk, and the once brawny arms soon become small and weak. Let a muscle be kept idle for some time, and it loses in bulk and vigor. Some of us have heard of certain people in India, who, as an act of worship, keep one arm raised above the head for many weeks. The muscles shrivel, and the arm dries up and becomes useless. If a leg is broken, and kept in splints for several weeks, the muscles become feeble and wasted. It is only after a great deal of exercise, that the long-idle limb regains its former size and vigor. 48. Effect of Exercise on Various Organs. — Not only are the muscles themselves benefited by exercise, but, by their action, many other tissues and organs become more vigorous. The heart beats more vigor- ously in order to carry more blood to the tissues. More oxygen is taken in by the lungs, and more heat is developed. Hence the skin, kidneys, and lungs have to do more work to get rid of the waste products. Breathing is mainly done by muscular action : thus, exercise causes the lungs to draw in an extra amount of fresh air, and to get rid of more impure air. Again, exercise stimulates the muscles which control the organs of digestion, thus giving a good appetite by creating a demand for food. In brief, muscular exercise is needed to keep the whole machinery of the body in good working order. 58 YOUNG folks' physiology 49- Amount of Physical Exercise. — Too much exercise, as well as too little, is a fruitful cause of ill- health. Exercise followed by fatigue, day after day, only does harm ; while judicious exercise with suitable rest is of great benefit. Hence the amount necessary to keep the body in the best trim is a most important and practical question. It is laid down as a pretty safe rule, that a person of average height and weight, engaged in study or any other in-door or inactive business, should have an amount of exercise equivalent to a daily walk of five miles along a level road. Growing children, as a rule, take more exercise than this ; while most men in the prime of life, working in-door, take nothing like this amount ; and many women take less. Of course, if one's daily Health and strength contrasted. — " Health and strength are not synonymous terms. A person may have great strength in his limbs, or in certain muscles about the body, but really not have good health. It is altogether a mistaken idea to suppose that physical exercises have for their sole object the attainment of strength. There are other tissues and organs in the human system besides the muscular ; and the healthy action of the lungs and the stomach is far more important than great strength in the arms, legs, or the back. It is here, in this general exer- cise of all the muscles and parts of the body, that a well-regulated system of gymnastics has its great excellence. It aims to produce just that development of the human system upon which good health is permanently based, described by a distinguished writer as follows : ' Health is the uniform and regular performance of all the functions of the body, arising frflm the harmonious action of all its parts,' — a physical condition implying that all are sound, well-fitting, and well-matched. Some minds do not look far enough into life to see this distinction, or to value it if seen ; they fix their eyes longingly upon strength, — upon strength now, — and seemingly care not for the power to work long, to work well, to work successfully hereafter, which is health" — Dr. Nathan Allen on Physical Culture. PHYSICAL EXERCISE 59 work is active and out-door, no additional exercise is really necessary. Exercise may be varied in many ways, — the more ways the better. But, for the most part, it should always be taken in the open air. 50. Time for Exercise The best time to take exercise is about two hours after a meal. The body is the weakest before breakfast. It is not best to do hard work, or take severe exercise, before this meal. Those who go to work or study before breakfast, should first eat half a slice of bread, or a cracker, or even drink a glass of milk, — just enough to "stay the stomach," and save the feeling of faintness, or "sinking" at the stomach. Just after a full meal, the stomach is busily doing its duty. Hence exercise at this time is apt to stop its action, and result sooner or later in dyspepsia. The evening is not the best time for exercise, because the body is tired after the labor of the day. It is useless to fix any exact rule. Ordinary work, or moderate exercise, as walking, is beneficial almost any time, except just after a full meal. 51. Different Kinds of Physical Exercise. — The kind of exercise it is best to take depends very much upon one's daily occupation. Persons who sit at desks, stand at counters, or work in close rooms, as clerks, teachers, tailors, printers, etc., are prone to diseases due to lack of bodily exercise and to foul air. Every person should know, or be taught to know, his own needs and his own dangers. All sound persons should do some work, or take some exercise, with both body and mind every day. To 60 YOUNG folks' PHYSIOLOGY get and to keep vigorous health, it is not at all neces- sary to increase the size of the muscles very much, or do great feats of strength. Walking is the best of all exercises. It takes us into the open air and bright sunlight. It puts new life into many important muscles of the chest, abdomen, and limbs. With a brisk walk every day, taking care to keep warm and dry, no one need suffer from lack of proper exercise. Running, leaping, climbing, and other vigorous sports are well enough, especially for children, if they are not kept iip too long, and cause fatigue. Violent sports, such as base-ball and foot-ball, are severe exercises, and occasionally dangerous. Rowing is admirably suited to most persons of either sex. Horse-back and bicycle riding, coasting, swimming, tennis, and skating are important helps to increase the bodily vigor. Certain sports also tend to beget self- reliance, coolness in danger, and a certain dignity and grace of person. There is hardly any one kind of exercise, which, taken alone, is able to give even toler- able development of all the muscles. Hence light gymnastic exercises are cheap and convenient means to develop muscles not used in work and games. Growing children should be trained every day at home or in school in the use of light wooden dumb- bells, light clubs or wands. A daily exercise of ten minutes will do much to develop feeble and narrow chests, to check the tendency to curvature of the spine and round shoulders so common with girls, and to give muscular strength and vigor to all parts of the body. PHYSICAL EXERCISE 6l 52. Beneficial Effect of Physical Exercises in Schools. — The measure of the health of young people depends to a great degree upon a proper amount of physical training. Hence pupils should have some sort of physical exercises provided for them in the schools. This is especially true in large towns and cities, where there is less opportunity for out-door games. Such exercises, whether of one kind or another, should form a part of the regular course of study. The object aimed at should be the promotion of health and power of work, rather than the development of muscle or the doing of feats of agility and strength. Such exercises, if of real value, increase the breath- ing-power, and quicken the action of the heart. They fill the arteries with pure blood, and distribute it, with increased energy, to all the tissues and organs of the body, stimulating them to renewed activity. They re- invigorate the whole system, and at the same time furnish what is very important, — a pleasant recreation. To obtain the greatest amount of good from all move- ments calculated to improve the physical and mental strength of young people, it is highly important to re- member that pupils should be interested, and made to feel that these exercises are a recreatibn instead of a task. 53. The Need of Physical Training in our School System. — Nearly one-half of the working hours of every pupil is spent in the schoolroom itself, or in the prepa- ration for the work there done. The conditions for the best physical development are rarely reached in our schools. 62 YOUNG folks' PHYSIOLOGY Impure air, lack of proper ventilation, faulty positions long continued, and other conditions unfavorable to health and normal development, demand a rest for the over-tired muscles and the over-taxed nerves. Hence the connection between physical training and school education is obvious. To the natural varieties of games and exercises used by boys — base-ball, foot-ball, bicycle, croquet, tennis, rowing — should be added systematic instruction in the schools. This should be especially directed with a view to develop the neglected and weak parts, and to add to the symmetry of the whole. The real benefit of systematic physical exercises in the schools, however, does not depend upon any large amount of development that they afford. They should be adapted to a harmonious development of the whole physical system, so as to result in a perfect control of every muscle, producing grace and freedom of move- ment, as well as health and vigor. Importance of Physical Development. — " In early boyhood and youth nothing can replace the active sports, so much enjoyed at this period ; and while no needless restrictions should be placed upon them, consideration should be paid to the amount, and especially to the charac- ter, of the games pursued by delicate youth. For these it would be better to develop the weakened parts by means of systematic physical exercises, by short excursions into the country, and by lighter sports. " Children who are taught at an early age to be obedient seem to en- joy more thoroughly such exercises as combine discipline with rhythmic movements; and consequently, the older the child, the more important it is to adopt a system of calisthenics, or light drill, or games that combine gymnastics with rhythmic sounds and periods of rest." — Dr. John M. Keating on Physical Developmetit in Pepper's Cyclopedia of the Diseases of Children. PHYSICAL EXERCISE 63 Simple exercises, without any apparatus, practised a few times every day for five or ten minutes at a time, do a great deal of good. . They relax the tension of body and mind, and introduce an element of pleasure into the rou- tine of school life. These simple but vigorous and syste- matic movements are of great use in schools of the lower grades, and are widely used at present with a real benefit. 54. The Various Systems of Gymnastics.— It is not the purpose of this book to discuss in detail the merits and defects of the various sys- tems of gymnastics now in general use in this country. They all have strong points — and their weak ones. The present revival of pop- ular interest in all that pertains to physical culture has stimu- lated our leading educators to renewed activity in urging a more systematic use of gymnas- tic exercises in our schools. We have sketched briefly in of a bird) in the Swedish driii, the following sections a few of the essential facts or prin- ciples that give character and utility to the two great systems (the Swedish and German) of gymnastic train- ing. Upon these two systems are based many of the valuable gymnastic movements now in common use in our schools. 55. The Swedish System of Gymnastics. — The Swedish system of physical exercises as arranged by Ling, and modified to some extent by the teachers of Fig. 31. — showing the "wing" position (arms resembling the wings 64 YOUNG FOLKS PHYSIOLOGY this method since his time, is generally regarded as having very important merits. The main principle which underlies all the movements of this system is to impart invigorating forces to the vital organs. Every movement is carried out with deliberation and mental attention, and designated by a phrase which can be used as a zvord of command. This word of command is the only method, the advocates of this system claim, which enables the pupil to concentrate his mind on one thing at a time, that thing being his own movement. Words of command have other advantages. They teach the pupil to think quickly, to act as quickly, and to do a thing in the shortest possible time. Again, in the Swedish system regularity of method is adhered to very strictly. The exercises eginning by the very simplest, gradually be- come stronger and more complicated as the pupils develop. The slightest change of position — even the turning of a hand — has its recognized influence in the progression. The exercises of the Swedish system can be practised in the school-room, most of them by the class in con- cert, and equally by boys and girls. The method does not approve of music, and reqjdres no apparatus. The exercises, not the apparatus, constitute the system. Fig. 32. — Showing the "rest" position (on 1. account of its restful feeling) in the Swedish drill. PHYSICAL EXERCISE 65 The movements can be made anywhere where there is sufficient floor-space to stand on and sufficient oxygen in the air. The apparatus can be easily adapted to the apparatus belonging to other systems, or to such simple .c5ya means as ordinary chairs and desks, and other furniture. Though apparatus is desir- able, it is not absolutely ne- cessary for good physical development, especially in gymnastics for children.^ 1 " The exercises of the Swedish system are chosen according to their gymnastic value,vih\chqua\\ty depends on how the movement combines the utmost effect on the body with sim- plicity and beauty of performance. Only such exercises are used whose local and general effects are fairly well known and proved to be needed by the body. Not only the needs of the individual, but his abilities as well, are to be taken into consideration ; and for that reason the teacher must know how to vary the exercises ac- cording to the degree of physical cul- ture possessed by the pupil. The movement should have its developing — ^; effects in a short time ; it should be Fio. 33. — Standing position in the simple, so that every pupil can do it Swedish system, ready for gymnastic drill, fairly well ; and it should have beauty of execution, according to each one's ability." — Baron Nils Posse, M.G. Note. — For a most comprehensive work on the Swedish system, the teacher is referred to the " Swedish System of Educational Gymnastics," with 264 illustrations, by Baron Nils Posse, M. G., Director of the Posse Gymnasium, Boston. A small manual for teachers, called " Handbook of School Gymnastics of the Swedish Systems," by Baron Nils Posse, has been recently published. 66 YOUNG folks' physiology 56. The German System of School Gymnastics. — The German system of gymnastics ranks high among all the different systems. It has been built up during almost a century by men of science. It is practised in classes at school by hundreds at the same time, and by single persons as home exercises. The Benefits derived from a Modern Gymnasium. — " I think it will be admitted by all thoughtful persons that one-half the battle for mental education has been won when you arouse in a boy a genuine love for learning. So one-half the struggle for physical training has been won when he can be induced to take a genuine interest in his bodily condition, — to want to remedy its defects, and to pride himself on the purity of his skin, the firmness of his muscles, and the uprightness of his figure. " Whether the young man chooses afterwards to use the gymnasium, to run, to row, to play ball, or to saw wood, for the purpose of improv- ing his physical condition, matters little, provided he accomplishes that object. "The modern gymnasium, however, offers facilities for building up the body that are not excelled by any other system of exercise. The intro- duction of the new developing appliances has opened up the possibility of the gymnasium to thousands to whom it was formerly an institution of doubtful value. " The student is no longer compelled to compete with others in the performance of feats that are distasteful to him. He can now compete with himself — that is, with his own physical condition — from week to week, and from month to month. If he is not strong enough to lift his own weight, the apparatus can be adjusted to a weight he can lift. If he is weak in the chest or the back, he can spend his time and energy in strengthening those parts without fear of strain or injury. " In fact, he can work for an hour, going from one piece of apparatus to another, keeping always within the circuit of his capacity, and adding slowly and surely to his general strength and powers of endurance. If the heart is weak, the lung-capacity small, the liver sluggish, the circu- lation feeble, or the nervous system impaired, etc., special forms of exercise can be prescribed to meet these conditions." — Dr. D. A. Sar- gent, Director of the Hemenway Gymnasium, Harvard University. PHYSICAL EXERCISE 67 The instruction begins with simple and easy move- ments, and gradually proceeds to those more difficult. The apparatus used in school practice is not compli- cated or expensive. It may be omitted altogether if the necessary room for climbing- poles, ladders, and some light apparatus cannot be provided for. An almost endless variety of simple and complicated free exercises may be made, with or without the common hand ap- paratus, as wands, dumb-bells, and Indian clubs. In the German schools the lessons begin regularly with a series of free and order exercises. Every scholar has to take part in them. The rhythmical order in which they are produced calls for absolute attention, and allows no backwardness. Class exer- cises on apparatus follow the free exercises. A change of appara- tus takes place, and then the lesson ends with some exercises _ left to individual inclination. .f-«- 34.-A schoolgirl in gym„as- tic costume. 57. The System needed for our Schools. — The various systems of physical exer- cises as practised in Europe have proved acceptable in this country, but with many important modifica- tions. American educators have ideas of their own on 68 YOUNG FOLKS PHYSIOLOGY physical culture. We are slow to adopt the methods of other countries unless they are modified to suit our special demands. Many of our ablest teachers of physical exercises believe in music in gymnastic training. They claim that many of the lighter exercises can be better exe- cuted with music. It is also maintained that it is no relief from the strain on the brain to go from the study of arithmetic to the performance of physical exercises that demand close attention to the teacher who gives the signal for the gymnastic exercises. In brief, the ideal system adopted for our schools must be an eclectic one. It will assimilate all that is best in every known method. It is not the system itself which must bear the test of criticism, but the way in which the system is taught. 58. Effect of Alcoholic Liquors and Tobacco on Physical Exercise. — The main object of physical ex- ercise is to get our bodies into such a condition, and to keep them in that condition, whereby the average amount of working-power can be utilized at any time without harm to the bodily health. To keep up this amount of physical power and endurance we must be obedient to certain great laws of health. One of these laws which never can be violated with impunity is that which forbids the use of alcoholic liquors and tobacco. Strong drink and tobacco will put to naught the most elaborate and costly system of physical training. Those who train athletes, base-ball and foot-ball PHYSICAL EXERCISE 69 players, oarsmen, and all others who take part in severe physical contests, understand this, and rigidly forbid their men to touch a drop of alcoholic drink, or even to smoke or chew tobacco. Experience has proved beyond all doubt that strong drink is a positive injury, either when men are in training for or undergoing contests demanding long-continued physical endurance. The same law holds good in the ordinary physical exercises of every-day life. Alcohol and tobacco act as poisons to the nerve-force which controls the muscles, and thus lessen the amount of muscular power and endurance. The demands of modern life call for a sound body rather than a strong body. Neither is possible to those who indulge in alcoholic drink or tobacco. Note. — In chapter xvi. may be found a series of simple gymnastic exercises, systematically arranged, which may serve as the basis of other and more extended exercises suitable for every-day use in the schoolroom. 70 YOUNG folks' PHYSIOLOGY CHAPTER V FOOD AND DRINK 59. Work, Waste, and Repair. — The body is in some ways — as we have learned in the Introduction — very much like a steam-engine. The bones and mus- cles correspond to the machinery. The motive-power is furnished by the food we eat. Our food is to us what coal and wood are to the engine. Like the locomotive, our bodies move about, and are warm, because a slow fire is always burning in them. This fire, like that of the engine, needs fresh fuel from time to time. The food we eat becomes part and parcel of our body, and it is our whole body that is slowly burning. In order to keep up this bodily burning, we must have oxygen. Without fuel and air, the fire in the engine will go out. So it is with the fire in our body. Without food and air, the combustion of our bodies would soon fla^, and we would soon die for want of them. When coal or wood is burned, we get ashes. When food is burned in the body, we get, not exactly ashes, but something like it, which is got rid of as useless substances. Again, the steam-engine wears out, and needs repair from time to time. So it is with our bodies. There is wear and tear constantly in every part. Every beat of FOOD AND DRINK "Jl the heart, every contraction of a muscle, and even our very thoughts, lead to waste. Every time we think, look, speak, or move, we do so at the expense of some minute portion of the tissues of the body. 60. Why we need Food. — To make good this waste, there must be something taken into the body, or it soon suffers. The body is constantly wearing away, and must be constantly built up again. Hence we see the necessity for food. The food, too, must contain the same things that the body has lost. The blood is the stream which carries this material for restoring the waste tissues of the body. Indeed, we may say that the blood is that material itself. It is simply the food we have eaten, in another form. Food must be of such a kind, and in such a quantity, as to supply an amount of nutriment to the tissues equal to the waste which takes place. During early life, when the body is growing rapidly, more of tissue-food is needed than in adult life, when repair alone is called for. When the body has been wasted by disease, as typhoid fever for instance, much tissue-food is needed to repair the waste, and to restore the muscles to their former size and vigor. If but little or no food be taken, or if it be not of the right sort, the body slowly loses in weight. If we try to do without food, we grow chilly and cold, feeble, faint, and too weak to move. A point will at length be reached at which death from starvation must take place. The bodily fire has gone out, and nothing but cold ashes is left. 72 YOUNG folks' PHYSIOLOGY 6i. Different Classes of Food. — For convenience let us divide foods, or foodstuffs, in four great classes : — I. Nitrogenons Foods, or Albumens. II. Starches and Sugars. III. Oil and Fats. IV. Inorganic or Mineral Foods. 62. Nitrogenous Foods, or Albumens. — These foods, sometimes called flesh-forming foods, contain, as their name implies, all the materials requisite for restoring the tissues. They contain all four elements, — nitrogen, carbon, oxygen, and hydrogen. They are especially rich, however, in nitrogen, which forms an essential part of the animal tissues. These foods are called albumens, because they con- tain a certain white substance known as albumen, familiar to all as the white of an egg. Lean meat ; the cheesy part, or curd, of milk ; pease and beans, — are The Wear and Tear of the Body. — " In the physical life of man there is scarcely such a thing as rest : the numberless organs and tissues which compose his frame are undergoing perpetual change, and in the exercise of the function of each, some part of it is destroyed. Thus, we cannot think, feel, or move without wasting some proportion, great or small, according to the energy of the act, of the apparatuses concerned, — such as brain, nerve, or muscles. Now, this waste-product cannot remain in its original situation, where it would not only be use- less dross, but also obstructive and injurious. Such old material is being daily removed from our bodies to the average amount of three or more pounds ; and that an equal quantity of new shall take its place is the first principle of alimentation. This tissue-change is so complete, that not a particle of our present body will be ours a short time hence ; and we will be, as I have lately seen it phrased, like the knife which, after having had several new blades, and at least one new handle, was still the same old knife to its owner." — Mapother's Lectures on Public Health. FOOD AND DRINK 73 rich in albumen. Wheat, barley, oats, and maize also contain albumen. A well-known group of plants with seeds enclosed in pods, or legumes, hence called "legumens," is rich in a nitrogenous substance, resembling the albumen of eggs and the gluten of flour. Pease, beans, and other vege- tables of this group, are nutritious on account of this flesh-forming material. 63. Starches and Sugars. — The starches and sugars contain carbon, hydrogen, and oxygen, but no nitrogen. They are sometimes called the "sugar hydrocarbons." As their proportions of hydrogen and oxygen are the same as in water, we may consider them as carbon or charcoal dissolved in water. This class of foodstuffs forms a large proportion of all those plants which are generally used as food. Wheat, barley, oats, rye, rice, maize, tapioca, arrow- root, sago, potatoes, etc., are rich in starch. In fact, starch stands first in importance among the various vegetable foods. Starch in its natural state would be useless as food, because it is insoluble. It is only after it has been acted upon by the digestive fluids, and con- verted into sugar, that it becomes soluble, and is capable of being taken up by the blood. The sugars themselves come from the fruits and vegetables, honey, and- milk. The sugars serve as a kind of fuel, which is burned up by the oxygen in the body. The combustion of these fuel-foods develops and keeps up the necessary heat of the body, and the vital energy or strength which enables us to perform our various duties. 74 YOUNG FOLKS PHYSIOLOGY 64. Oil and Fats. — These foods contain carbon, hydrogen, and oxygen. They are sometimes called the "fatty hydrocarbons." This class of foods is derived from the fat of meat, eggs, butter, and milk, also from the various oils. Most of the breadstuffs contain more or less of fat or oil. The oils and fat supply about twice the amount of energy, whether manifested as heat or motor force, as that afforded by the combustion of an equal amount of starch or sugar. 65. Inorganic Substances, or Mineral Foods. — Organic substances, such as those included in the food- stuffs just described, are derived from living forms, as animals and vegetables. Besides these, the body de- mands a certain amount of inorganic substances, derived from the mineral kingdom. These are water, salt, iron, lime, magnesia, phosphorus, and potash. Except water and common salt, these substances generally enter the body only in combination with other foodstuffs. 66. Extra Foods, or Appetizers. — A vigorous appe- tite requires little else besides salt for an appetizer. Salt has been and is universally used by all animals and peoples. Salt has always been the symbol of life, hospi- tality, and wisdom. Animals will travel for miles to reach salt-licks, while men have risked their lives to get even a taste of salt. Pepper, mustard, ginger, and other heating appetizers, are used to give flavor to taste- less foods, and to stimulate the sense of taste, and to in- crease the flow of saliva and gastric juice. So long as the "appetite comes with eating," and ordinary food is enjoyed, the use of these stimulating appetizers is un- necessary, and becomes simply a matter of habit. FOOD AND DRINK 75 67. Different Articles of Diet. Vegetable Food. — The most important food of this class is bread, "the staff of life." There is no single food in the world which meets so many necessary wants of the body. Bread is made from the flour of many kinds of seeds, such as oats, rye, Indian corn, etc. But in this country it is nearly always made from wheat. Wheat-fiour gives us starch, sugar, gluten, — a form of albuminous food. Hence wheat has nearly everything to support life except fat. When we eat bread and butter, we have nearly a perfect food. Corn-meal is rich in nitrogen, and has much oily matter. It is highly nutritious and a cheap article of food. Oatmeal is richer than flour in nitrogen and fat, and is therefore more- nutritious. Rice, though rich in carbon, is one of the least nutritious of all the cereals. Pease and beans contain more nitrogen than any of the cereals, and are as rich in carbon as wheat-flour. The common, or Irish, potato is a most important article of diet. Although it is more than two-thirds water, and has little nutriment, yet it is easily digested, — a cheap and economical article of diet. Ripe fruits, such as apples, pears, peaches, melons, grapes, oranges, etc., though not of much nutritious value, are prized for their agreeable flavor. Sugar and molasses are both largely used in cooking. Their nutritious value is about the same as that of starch. 68. Animal Food. — The first place must be given to milk, for it is the food of all others which gives us nourishment in the simplest and best form. It con- tains a large quantity of water, caseine, together with •j6 YOUNG folks' physiology sugar and fat. Eggs have a large amount of nutriment in a small space. Two-thirds of an egg is water, the rest albumen and fat. Eggs are cooked in many ways, and are generally easily digested. Meats, for the most part, consist of the muscles of the various animals. The most common are beef, mut- ton, lamb, veal, and pork. Meat is rich in albumen, and has more or less of fat. It is a most common and important article of diet, and, as a whole, is easily digested, except, perhaps, veal and pork. Fish is at once a cheap, abundant, and nourishing food. Poultry is a useful, light article of food, especially for the sick and feeble. - The flesh is easy to digest, and gives a deal of nourishment. 6g. Mineral Food. — Water is a mineral food, which will be described hereafter. There is about a half a pound of common salt in the body at any one time. But we are continually losing it. Tears, we know, con- tain salt ; and it is also found in the sweat. Many people think they do not eat any common salt, because they do not take it by itself ; but they forget that many of the foods they eat, such as bread and meat, have a little of it. The salts of potash are chiefly found in the vege- tables we eat, especially lettuce. These salts help purify the blood. The salts of lime make the bones hard and strong. Iron is contained in very small quan- tities in many of the foods we eat. It helps to make good blood. 70. Natural Drink. Pure Water. — Drink is of just as much importance as food. Every one knows what hap- FOOD AND DRINK jy pens to plants when they are deprived of their drink. They first droop, and then, soon afterwards, wither and die. So also it is with all animals. If they are deprived of their drink, they also droop, and at last die. Animals may be dried away into death as certainly as plants. Drink is the agent which has been provided by nature to wash the food into and through the living tis- sue of bodies. The drink provided by nature for all living creatures is pure water. Wild animals, as well as domestic, take no other drink but water. The Value of Salt. — In most countries, salt is "cheap as dirt;'' while in parts of Africa it is worth its weight in gold. In that land brothers will barter their sisters, husbands their wives, and parents their children, for salt. On the Gold Coast of Africa a handful of salt is the most valuable thing upon earth after gold, and will purchase a slave or two. Travellers tell us that with certain tribes the use of salt is such a luxury that to say of a man, " He flavors his food with salt," is to imply that he is rich ; and children will suck a piece of rock-salt as if it were sugar. In India a large revenue is raised from the salt-tax, salt being something which even the poorest native will buy. In old times untold tortures were inflicted upon prisoners in Holland, by feeding them on bread alone, made without salt. No stronger mark of respect or affection can be shown in some countries tlian the sending of salt from the tables of the rich to their poorer friends. In the Book of Leviticus it is expressly com- manded, as one of the ordinances of Moses, that every oblation of meat upon the altar shall be seasoned with salt, without lacking; and hence it is called the Salt of the Covenant of God. The Greeks and Romans also used salt in their sacrificial cakes. Everywhere, and almost always, indeed, salt has been regarded as emblematical of wisdom, wit, and immor- tality. To taste a man's salt, was to be bound by the rites of hospitality ; and no oath was more solemn than that which was sworn upon bread and salt. To sprinkle the meat with salt was to drive away the Devil ; and to this day, among the superstitious, nothing is more unlucky than to spill the salt. 78 YOUNG folks' physiology Thousands of human beings, following the example of the lower animals, drink nothing but water, but yet toil long and hard, and fulfil all the duties of a reason- able and intelligent existence. In brief, it is clearly evident that pure water is the only drink that is absolutely essential for all the pur- poses of life. Now, it is plain that if we take a quart or more of drink every day, nearly an equal amount must be thrown out daily from the body. This is really the fact. Some portion of it steams away with the breath. More of it passes through the pores of the skin, and still more is drained away through the kidneys. Water thus drains off a great deal of waste and refuse matter that the body must get rid of. Water therefore drains waste matters out of the body at the same time it washes nourishing foods into it. To be suitable for diet, water should be clear, with- out color, with little or no taste or smell, and free from any great amount of animal or vegetable matter. Real pure water does not occur in nature. Rain-water is the purest if properly collected. Well and spring water, and that brought into towns from some distant pond or river, all contain more or less mineral matter. The vari- ous mineral-spring waters, such as those' at Saratoga, popularly used as medicines, are highly charged with mineral substances. 71. Artificial Drinks. — Our great natural drink, as we have learned, is pure water. Milk is also a natural drink. We have already learned some things about milk and water. Now, man has always contrived many FOOD AND DRINK 79 ways to flavor his drink in some way or other. The greater portion of almost every drink is water; but, in various ways, other substances are mixed with the water, to give it a pleasant taste. Such drinks are arti- ficial. Tea, coffee, and cocoa are the more common artificial drinks. Tea was first brought to England about two hundred and fifty years ago, but it did not come into general use. The tea-plant is chiefly cultivated in China. When boiling water is poured on the dried leaves, a substance which chemists call an "active principle," and known as theine, is dissolved. The liquid so obtained is called a " decoction," and makes the com- mon drink known as tea. Coffee comes to us mainly from the West Indies, Ara- bia, South America, and the East Indies. When boil- ing water is poured on ground coffee, it dissolves a substance called caffeine, very much like the theine of tea. The cocoa or chocolate tree is a native of tropical America. It has an active principle which resembles theine and caffeine. Chocolate is cocoa ground up with sugar and certain spices. One of the most common of all artificial drinks used in this country is ice-water. The temptation to drink freely of it in hot weather is rarely resisted. Ice-water quenches the thirst only for a moment. It weakens the strongest stomach after a time, and is thus a com- mon cause of dyspepsia. If one must drink it, sip a little slowly. 8o YOUNG folks' PHYSIOLOGY The most common of all artificial drinks are alcoholic liqnors. In the next chapter we shall learn a great deal about their origin and nature. 72. The Effect of Drinking Tea and Coffee. — There is rarely any necessity for one to drink tea or coffee. They have little or no value as foods. Some per- sons cannot drink even a single cup of coffee or tea without feeling the worse for it : headache, indigestion, heartburn, wakefulness at night, and constipation are the most common after-effects. Strong tea should never be used. Hard-working women and others, from choice or necessity, too often make their meals of dry toast and several cups of strong tea. Drank in excess, tea may weaken the action of the heart, and produce the pecul- iar beating, after much exertion, known as "palpita- tion." Hence we have "the tea-drinker's heart." Coffee and tea are unsuitable articles of diet for grow- ing children. Drinking strong coffee often gives a muddy look to the complexion of young folks ; much tea-drinking imparts a parchment appearance to the skin of young women. Doubtless all of us would be in better health if we never drank another drop of tea or coffee. ORIGIN AND NATURE OF FERMENTED DRINKS 8 1 CHAPTER VI ORIGIN AND NATURE OF FERMENTED DRINKS 73. Decay a Law of Nature. — If one is thirsty and cannot get water to drink, his thirst can be greatly relieved by juicy fruits. Fruit-juices are com- posed largely of water, sweetened with sugar, which nature prepares in them as the fruit ripens, and flavors each according to its kind. Such juices, as they come fresh from the fruit, are healthful. But suppose the fruit is crushed, and the juice is drawn off and left standing in air of ordinary tempera- ture. How long will it remain a healthful drink .' Only a very few hours. All animal and vegetable matter is composed of vari- ous simple substances, gases, liquids, and solids. Nature has provided that when plant or animal matter ceases to live, these different substances composing it shall be set free for use again in forming new combinations. When we see meat spoiling, bread or cheese moulding, fruit rotting, or sauce turning sour, we see simply an example of this provision.^ The "working," or fermenting, of sweet fruit, plant, or other vegetable juices, which takes place very soon after they are pressed out, is another example of the same wise provision. This last process is not accom- panied by foul-smelling odors, as are most of the others, but by a peculiar bubbling of the liquid caused by the 1 See Note 4, page 358. 82 YOUNG FOLKS PHYSIOLOGY escaping gases ; hence the name " fermentation," from the Latin meaning " to boil." Fermentatipn in its widest sense includes the changes going on in the putrefying meat, the moulding cheese, and the rotting fruit, as well as in the fermenting fruit- juice. They are all forms of decomposition that set free the simpler substances composing animal and vege- table matter. For all these one law holds good. It is this: — Fermentation entirely changes the nature iIc'of THE substance FERMENTED. ;)ice 74. The Cause of Decay. — What causes i^^^ ill these various processes of decomposition ? Are plaiga "^'^ ^^^ animals so constructed that when they have'- rjec^^''^^'^ their purpose they fall to pieces of themselves, or i/f^om the action of the air, as was once supposed ? No : the microscope has introduced to us whole tribes and fam- ^ ilies of minute living forms whose special work is to cause this decomposition of the dead bodies of their neighbors. Were it not for these the whole surface of the earth would in time be covered with dead trees and other life- less bodies, and there would be no simple substances left out of which to build up new ones. Among these minute living forms are some that do not even wait for a plant or animal to die before attack- ing it. Such are the disease germs invisible to the naked eye, lurking in the air we breathe and in the water we drink, ready to cause sickness if given a lodgement. ORIGIN AND NATURE OF FERMENTED DRINKS 83 Many kinds of these have been studied and described and grouped under the family name of Bacteria, the lowest of the plant-families. The decay of meat and the souring of milk are caused by minute plant-cells belonging to this family. To an- other family low down in plant-life, viz., the fungi, belong the moulds that spoil our bread and cheese, and cause our sauce to sour and our fruit to rot.^ 75. Ferments and Their Work. — To the fungi family also belong the class of microscopic plants called Ferments that cause the fermentation of sweet fruit, plant, or other vegetable juices. As long as fruit- juice remains inside the fruit the ferment germs float- ing in the air, and even resting on the skins and stems of the fruit, do not enter it.'^ When apples are ground to make cider, or grape- juice is pressed out to make wine, the ferments resting on their surfaces are washed into the expressed juice. Each ferment rapidly produces others, unless the liquid is kept at a very cold temperature, and all begin at once to break up the sugar of the juice.^ Two substances set free by this decomposition of the sugar are carbonic acid gas, which may be seen coming 1 See Note 5, page 359. 2 " Fermentation is the consequence of a development of vegetable cells, the germs of which do not exist in the saccharine juices within the fruits." — Pas- teur's Studies in Fermentation. * " In the fermentation of natural saccharine juices, which, especially when acid, undergo a decided alcoholic fermentation, the ferments originate in certain germ-cells which are spread in the form of minute spherical bodies of a yellow or brown color, isolated, or in groups, over the exterior surface of the epidermis of the plant, and which are gifted with an extraordinary power of budding with ease and rapidity in fermentable liquids." — Pasteur's Studies in Fermen tation. 84 YOUNG folks' physiology up out of the liquid in tiny bubbles, and alcohol, a poison which remains in the liquid. The whole nature of the fruit-juice, which was whole- some and beneficial before this fermentation took place, is now changed by the presence of the alcohol. It be- comes a poisonous liquid, called cider if made from apple-juice ; wine if made from the juice of grapes, berries, currants, and other fruits. If man should then leave this fermented liquid to itself, other kinds of ferments would enter it, and carry on the process of decomposition by setting up other kinds of fermentations, each after its own kind. For every fermentation, it must be remembered, has its own special ferment. Among the minute plant-cells belonging to the bac- teria family is one whose special work is to change the alcohol of a fermented liquid to acetic acid. Thus the fermented juice becomes vinegar, which contains no alcohol. Left again to itself, other forms of the bacte- ria enter the vinegar, causing still further changes, until finally the water is all evaporated and nothing but a little earthy matter is left. The work of decomposition is then finished. But man interferes. He prevents, if possible, the microbe of vinegar from entering the fermented fruit- juice that he may use it for a drink. In many cases he is ignorant of the nature of the poison which the fer- ments produced by destroying the sugar. 76. Alcohol as a Poison. — Any substance capable, when absorbed into the blood, of injuring health or de- stroying life, is a Poison. Alcohol is capable of destroy- ORIGIN AND NATURE OF FERMENTED DRINKS 85 ing life when taken in sufficient quantities, as has been proved by numerous instances of death following the drinking of spirits on a wager, or a draught of brandy or gin taken in ignorance by a child. Alcohol is also capable of injuring health, as is proved over and over again every day. Few people have not known of one or more cases of loss of health from this cause, while physicians are meeting them constantly.^ Remember this : Alcohol is a Poison. It is classed as such in standard treatises on poisons, in Alcohol a Poison. — "Alcohol is universally ranked among poisons by physiologists, chemists, physicians, toxicologists, and all who have experimented, studied, and written upon the subject, and who, therefore, best understand it. It is not necessary to the action of poisons that they be always swallowed in fatal doses." — Professor W. J. Youmans. Is alcohol a poison ? I reply, yes. It answers to the description of a poison. It possesses an inherent, deleterious property, which, when in- troduced into the system, is capable of destroying life, and it has its place with arsenic, belladonna, prussic acid, opium, etc. In its effects upon the living system alcohol is first an irritant, and afterward, when it has entered the circulation, it becomes a narcotic. Were alcohol an irritant only, a man would as soon poison himself with arsenic. The narcotic element is the Siren that leads him on to ruin andtodeath." — Dr. Wil- LARD Parker. " Alcohol is classed among the poisons by medical writers on poisons. I do not know of an exception among physicians. It is ranked among the poisons from its effects on the body analogous to those of the other poisons. What is said of the effect of alcohol must be true of all doses, large or small, although the effect of very minute doses may be imper- ceptible. Arsenic may be administered in doses so small as to produce no apparent ill effects; yet no one doubts that arsenic is a poison. . . . If a person dies of delirium tremens, it is not the last glass that kills him, but every dose or glass he has taken in his life has conduced to the result." — Dr. Reuben D. Mussey. 1 See Note 6, page 351. 86 YOUNG folks' physiology medical dispensatories, and by eminent medical writers too numerous to mention. Certain poisons whose action is to deaden or paralyze the brain and nerves are called narcotic poisons. Alcohol is classed by the authorities among the narcotic poisons, because of its paralyzipg effect on brain and nerve sub- stance, of which we shall learn later.^ 77. The Alcoholic Appetite. — A celebrated physician has said, " If a person eats bread three times a day for twenty years he is just as readily satisfied at the end of the time as he was at the beginning. Natural appetite, or hunger, is simply the demand for material to supply the growth or waste of tissue. Every substance capable of assimilation will satisfy that demand, and with that sat- isfaction ceases, for the time being, all relish for more." This is not the case with alcohol. Its worst charac- teristic is its power to set up a perpetual craving for itself, which calls for repeated and increasing amounts,^ This is called the alcoholic appetite. All natural appe- tites have natural limits. But the appetite for alcohol, created by the diseased conditions which it has itself produced, has no natural limit. From the first glass of the boy just beginning to drink to the dram of the drunkard whose tissues are poisoned and inflamed by it, its nature is ever to excite a thirst for more. Whether it is drank in the form of wine, beer, cider, rum, or whiskey, its character is the same ; for the character of any substance depends upon its quality, not its quantity. The secret of the drunkard's craving for alcohol is in the nature of the drink, rather than in the weakness of the drinker. 1 See Note 7, page 362. 2 See Note 8, page 363. ORIGIN AND NATURE OF FERMENTED DRINKS 8/ There is a scientific connection between the first glass and the drunkard's fate. No one is safe who begins to take any liquor containing alcohol. Entire abstinence is the only safeguard against forming the alcoholic appetite, and the only cure for it when it is formed. Because of the ease with which the alcoholic appetite is roused where it has been once formed, and the power of a little to form such an appetite, no liquor containing alcohol should ever be used as a flavoring for pies, pud- ding-sauces, jellies, or aiiy other article of food.^ The habit of treating one's friends to beer, wine, or any other alcoholic drink, is simply asking them to poison themselves at our expense. Such treating is a mark of ignorance rather than an evidence of real courtesy or friendship, and must be so considered by one who understands the true nature of such substances. Furnishing wines or liquors at parties, dinners, or other entertainments, or for guests or callers, is virtu- ally offering poisonous drinks, and is never an act of true or intelligent hospitality or real kindness. It may be placing temptation too strong to be resisted in the way of an inherited or acquired appetite for alcohol. 78. Cider. — The fermented juice of apples, known as cider, contains alcohol varying in amount with the length of time it is allowed to ferment. When cider remains in air of the ordinary temperature, alcohol can usually be found in it in about six hours from the time it comes from the press, sometimes sooner. The power which alcohol has to create an appetite for itself makes a bev- erage containing it in any quantity an unsafe drink. As cider grows older it is said to be growing hard ; i.e., 1 See Note g, page 365. 88 YOUNG folks' physiology the amount of alcohol in it is increasing. Hard cider often contains ten per cent of alcohol. If a person begins, when the barrel of cider is first put in the cellar, to drink one or two glasses every day, and continues the same amount daily as the cider grows hard, he is every day getting more and more alcohol, which, besides be- numbing his brain, hardening his heart, and spoiling his temper, has the power to create the craving that nothing but alcohol, in ever-increasing amounts, will satisfy. Note this : Many drunkards have acquired the ap- petite for strong drink at the cider-barrel. 79. Wine. — Wine is made chiefly from the juice of grapes. It can be made from the juice of berries, cur- rants, and other fruits. Drinks called home-made wines are frequently made from such fruits. But the ferments that produce alcohol are in the air and on the skins of the fruit ready to set up the pocess of fermentation as soon as their juices are pressed out. They cannot get inside the whole fruit to make alcohol, hence we are in no danger of being injured by alcohol when we take our fruit-juices fresh from the fruit itself. Some wines called " light wines " contain a smaller amount of alcohol than others ; but even the lightest wines contain alcohol enough to make them dangerous drinks. The power of alcohol to create an appetite for more does not change with the quantity. The theory that the use of light wines will prevent the use of stronger drinks, and so diminish drunkenness, is disproved by the history of countries where such wines have come into general use. Where the alcohol in the light wines does not lead to a use of stronger ORIGIN AND NATURE OF FERMENTED DRINKS 89 drinks, enough more of the weaker drink is taken to pro- duce an equal amount of drunkenness. Almost whole communities, including men, women, and children, in some wine-making districts, will be in a continual state of drunkenness during a large part of the vinting season.^ 80. Beer. — -Certain of the fermented drinks are called "malt liquors." These are beer, ale, and porter, which are made from barley and other grains. The starch of the grain is turned to sugar by keeping the grain warm and moist until it is sprouted. Heat is applied to kill the sprouts ; and the grain, then called malt, is ground or mashed, and soaked in water. To the sweet liquid thus obtained is added yeast, which is a kind of ferment, and hops. The yeast sets up vinous fermen- tation, which changes the sugar of the wort to alcohol and carbonic acid gas. The gas escapes in bubbles, pro- ducing a froth on the top of the fermenting-vat. The alcohol does not escape : it remains in the beer, mak- ing it a poisonous drink. Beer is responsible for many crimes. It seems to have a benumbing effect upon the moral nature that prepares the drinker for wicked and cruel deeds and for deliberate crime.^ A copious beer-drinker often looks the very picture of health, and boasts of the healthful- ness of his favorite beverage ; but the testimony of physicians, surgeons, and life-insurance companies is 1 See Note 10, page 365. ^ " Beer and wine do not give strength for worl<, but, on the other hand, often make people dull, heavy, stupid, and unfit for work. The most severe and con- tinued work can be performed without them, and there are now some millions of p'eople in this country who never taste them. Happy will be the day when they are not drank by any, but particularly by the workingman, who finds it difficult to maintain his family. Then will there be less quarrelling, poverty, and crime, and more food, clothing, and education."— Dr. Edward Smith of London. go YOUNG folks' physiology that the beer-drinker, of all others, is most liable to swift and sudden death from some slight causes.^ The surgeon dreads him for a subject, for his blood is often in such a state that a slight cut may develop into a gangrenous wound that ends quickly in death. A slight cold brings on a fatal pneumonia in spite of the best physician's efforts. The president of a leading life-in- surance company said once of this class of drinkers : — " It was as if the system had been kept fair outside, while within it was eaten to a shell, and at the first touch of disease there was utter collapse : every fibre was poisoned and weak. And this, in its main features, varying, of course, in degree, has been my observation of beer-drinking everywhere. It is peculiarly deceptive at first, and it is thoroughly destructive at the last." Various kinds of domestic drinks are sometimes pre- pared by adding yeast to sweet liquids in which roots or bitter herbs have been steeped. Those who make them are frequently not aware that they contain alco- hol ; but the yeast acts on the sugar of the sweet liquid, just as it does on the sweet grain-juice, and changes it to alcohol and carbonic acid gas. 8i. Distilled Liquors. — By heating a fermented liquid, the alcohol in it can be readily driven off in the form of vapor. This is condensed in a cool receiver, and the result is a new and stronger liquor. This pro- cess is called distillation. The alcohol of commerce is distilled mostly from whiskey. Beverages thus distilled from liquids which contain alcohol are commonly known as " spirits " and " ardent (burning) spirits." Brandy is distilled from wine, and J See Note ii, page 367. ORIGIN AND NATURE OF FERMENTED DRINKS 9I rum from fermented molasses. Distilled liquors con- tain from forty to fifty per cent of alcohol, — the rest being water, flavored with various aromatics. When the beer, wine, or cider drinker has acquired such a craving for alcohol that the amount in those weaker drinks no longer satisfies him, he resorts to these stronger liquors. These are still more harmful ; and even if they do not bring the drinker swiftly to drunkenness, they so injure his body and mind that he never realizes the happmess, respect, and usefulness that he might otherwise have enjoyed. In place of happiness he has misery ; instead of respect, contempt ; and instead of usefulness, he becomes a burden to others. He sees, when too late, how different his life might have been but for his first glass, that led on to others and their consequences. A Costly Vice. — The annual report of the Commissioner of Internal Revenue for 1891, shows that the business of manufacturing intoxicating liquors has grown in the past year to a magnitude which it had never reached before. The spirits produced and deposited in distillery ware- houses during the last fiscal year amounted to about one hundred and sixteen million gallons, and the quantity of spirits in the distillery ware- houses at the end of the year was one hundred and thirteen million gal- lons, — the largest quantity ever known in these places. Outside of the warehouses there were, according to the figures of the Internal Revenue Bureau, about one hundred and fifty-three million gallons of spirituous liquor in the country. A total of two hundred and sixty-six million gal- lons of spirits, to be consumed chiefly by the people of the United States 1 It would require a vivid imagination to conceive a tithe of the crime, misery, suffering, wretchedness, and death, that are included in that vast bulk of intoxicating liquor. It is estimated that the liquor con- sumed in the country costs the people one billion dollars a year. 92 YOUNG folks' PHYSIOLOGY CHAPTER VII DIGESTION 82. General Plan of Digestion. — Food cannot serve the needs of the body imtilit has been converted into blood. In order to become blood, food must first be dissolved: This is done in the alimentary canal. This canal is a long tube, which runs through the body from the lips to the lower end of the spine. Beginning at the mouth, this canal, continued as the gullet, passes down through an opening in the dia- phragm, which forms the partition between the chest and abdomen. Below this it swells out into a large bag called the stomach. It then narrows again into the small intestine, which lies coiled upon itself in the cavity of the abdomen. It then swells out again into the large intestine, from which are discharged the use- less parts of the food, together with certain other waste products. This long digestive tube is lined throughout by a soft, moist, reddish kind of very thin skin, called mucous membrane. Layers of muscles surround the tube, which strengthen it, and help push along the food. In and around this tube are hollow organs, called glands.i They pour out certain fluids, which 1 Glunds are curious organs, of various shapes and sizes, whose special work it is to take out of the hlood something to be used again, or to rid the blood of something to be cast out of the body. Thus the salivary glands make saliva, or spittle, and the sweat glands-smake sweat. The liver, which weighs about five pounds, is a single gland, and^'s^retes bile ; while the glands in the intes- tines are so very small that they cannot be seen by the naked eye. DIGESTION 93 alter the food chemically, and so fit it for absorption into the blood. Fig. 35. — Blackboard Diagram of tlie Digestive Canal. The process by which the food is made fit to mix with the blood is called digestion. 83. What takes Place in the Mouth. Chewing of 94 YOUNG FOLKS PHYSIOLOGY the Food. — The month is a hollow box, with a movable floor formed by the tongue and lower jaw. At the top is the hard palate ; in front, the lips and teeth ; and at the sides, the cheeks and teeth. The moment food is taken into the mouth, it is rolled over by the tongue, and crushed and ground into very small pieces by the teeth. This process is called chewing, or mastication. 84. The Teeth. — The teeth are small, hard, white, bone-like bodies fixed in the jaws, pressing against each I f ^f f I m % r •% 1/ Fig. 36. — The Adult Teeth. — i, (cuspid). 4, 5, Small grinders (bicuspids). 2, The cutting teeth (incisors). 3, Canine 6, 7, 8, Grinders (molars). Other as the jaws work, so as to cut and grind the food. They are fastened into the jaws by roots, which sink into the bony sockets somewhat in the same way as a nail is held in a piece of wood. Teeth are made of three things, — dentine, cement, and Dentine, the familiar ivory of commerce, is a DIGESTION 95 bone-like substance, which forms the inside and body of the tooth. Outside of this dentine is a layer of cem- ent ; but, when the tooth appears above the jaw, the enamel takes its place. It is a hard, shining kind of polish, looks like ivory, and gives a strong protection for the exposed part of the tooth, called the "crown." Inside of each tooth is a space which holds a delicate substance called the pulp, well supplied with nerves and blood-vessels, which enter at the root of the tooth. Fig. 37. — Diagram showing the apposition of the teeth. A child when born has no teeth : afterwards, how- ever, it has two sets. The first set, or milk-teeth, twenty in number, are shed in childhood. The second set, or permanent teeth, thirty-two in number, gradu- ally take their place. The teeth are arranged in the same way, and number thesame^in each jaw, and in each half of each jaw. 96 YOUNG folks' physiology L— f Voww; Thus, beginning at the centre of the jaw, there are eight incisors, or cutting-teeth, or two on each side. They have sharp, chisel-like, cutting-edges, which cut up the food. These teeth are largely developed in gnawing-animals, such as rabbits, squirrels, rats, and the beaver. Then come the canine, or dog-teeth, two in each jaw, so called because they are strongly developed in dogs, cats, tigers, and other flesh- eating animals. Next in order come the two- pointed teeth, called the bicuspids, four in each jaw. They are so called because they have two points or cusps, for grinding the food. ""■"S After these come the largest and strongest teeth in the head, which do the hardest work. They are called molars, or " grinders." There are six of them in each jaw. They have broad crowns, with four or five cusps or ridges for grinding. The last molars are commonly called the " wisdom- teeth ; " because they do not usually appear before the age of twenty, or the "age of wisdom." 85. Mixing the Food with Saliva. — While the food is being chewed, it is moistened by a liquid called the saliva, or spittle, which flows into the mouth from six little glands. They are known as the salivary glands. There are three of them on each side, in Fig. 38. — Vertical Section of a Bicuspid Tooth (magnified). DIGESTION 97 the following positions : The parotid gland, below and in front of each ear;^ the subinaxillary, under the lower jaw ; and the sublingual, under the tongue, in the floor of the mouth. Each gland opens into the mouth by a little duct. They have a certain resemblance to a bunch of grapes, with a tube for a stalk. Fig. 39. — Salivary glands, with their ducts, on the right side. Saliva is rapidly poured into the mouth while the grinding of food is going on. Three or four pints of saliva 1 This gland, especially in childhood, sometimes becomes inflamed and swollea This disease is familiarly known as the " mumps." 98 YOUNG folks' physiology are secreted daily. Sometimes these glands are bus- ily at work, even before we actually taste food. Touch the tongue with the finger, and the saliva will flow : it also pours into the mouth, even at the sight, smell, or thought of food. This is what is commonly called " making the mouth water." What is meant by Secretion. — It is necessary to explain at this point the exact meanuig of secretion and excretion. The word secretion comes from a Latin word which means to " sift or sepa- rate : " excretion comes from the Latin, and means " to sift out from.'' Both words are used to express the sifting of some substance from the blood. A secretion is something talcen from the blood to be used again in the body for some special purpose ; while an excretion is waste matter, and i is thrown out of the body entirely.. Thus, the salivary glands secrete j the saliva, and the liver secretes the bile. Sweat is an excretion, thrown ' off from the body by the sweat-glands. Those parts of the body which are engaged in secretion and excretion are called glands. There are a great number of glands in the body, varying in size, from the liver, which weighs about five pounds, to the small glands in the intestines, which are invisible to the naked eye. All glands, from the simplest to the most complex, have the same foundation structure. They are built, so to speak, of identical material. They con- sist essentially of a fine skin, or membrane, which is covered on one side with a layer of exceedingly minute bags called epithelial cells ; while it rests upon capillaries on the other side. These cells have the power of drawing the peculiar secretion of the gland out of the blood that is cir- culating through the capillaries. The moist, tender skin, or lining, on the inside of our lips, is a familiar example of this secreting-membrane. A gland may be merely a pouch in the basement membrane ; or the membrane may be elaborately twisted, branched, made up like bunches of grapes, and so on, into all kinds of complex glands. Why and how the cells in the liver make bile, and not gastric juice; those in the stomach make gastric juice, and not sweat; those in the skin make sweat, and not saliva ; and so on, — we do not know, and we can hardly imagine. Excretion will be described in full in chapter xiii. DIGESTION 99 The saliva not only softens and mixes with the food, and keeps the mouth moist, but it also has the power of acting upon all starchy matters in the food, and changing them into sugar. These starchy matters, as we have seen, before they are mixed with saliva, are insoluble ; but, when changed into sugar, they are quickly dissolved in the stomach, and taken up by the blood.i 86. How Food is swallowed. — The food is now ready to be swallowed. The soft, moist mass is carried back- wards by the tongue and the muscles of the mouth into the funnel-shaped top of the gullet, called the pharynx. I The soft palai^ pushes up and backwards, so as to pre- 1 vent the foot 'from passing into the nose.^ ' Now, besides the opening from the pharynx into the stomach, there is also one into the windpipe. To prevent the food from getting into this opening, and choking us, the top of the windpipe is protected by a little lid, a kind -of trap-door, called the epiglottis. When we swallow,- ' the tongue, raised and pushed backwards, shuts this little lid ; and thus a bridge is 1 We can easily prove that the saliva changes starch into sugar : hold some boiled starch — or a little arrowroot, which is almost pure starch — in the mouth for a few minutes. We find that it gradually loses its thick, pasty, nature, and becomes thin and watery, while at the same time it acquires a sweet taste. The fact is, the saliva has acted on the starch, and changed it into sugar in order to make it soluble. This shows the necessity of properly diewing our food: If we bolt our food without sufficiently chewing it, the saliva does not act properly upon it, and a great amount of extra work is thrown on the intestines. 2 During and after a severe attack of diphtheria, scarlet-fever, etc., in which diseases the parts of the throat are apt to be partially paralyzed, the soft palate is not able to shut off this passage into the nose : as a result, milk and other food often come up through the nose. lOO YOUNG FOLKS PHYSIOLOGY made, over which the food passes downwards into and through the gullet, and thence into the stomach. Some- times, however, a morsel of food " goes the wrong way," — that is, is drawn into the opening of the wind- FlG. 40. — Section showing Passages to the Gullet and Windpipe. pip&, or down into the air-tubes, — and then violent coughing follows : by this means it may be brought up again. If the substance is hard and large, like a boot- button, orange-seed, or peanut, a person, especially a child, may be choked to death. DIGESTION lOI The gullet, or food-pipe, is a tube about nine inches long, hanging loosely behind the vindpipe. Its thick walls are provided with hoop-like muscles, which con- tract with a worm-like motion, well seen when a horse is drinking water, and so push the food along towards the stomach. The pellet of food is passed along from above downwards by these muscles ^ in some such way as we would push a ring along inside of a rubber tube. 87. Digestion in the Stomach. — The food, a moist- ened, partly-digested mass, has now reached the stom- ach. !> The stomach is a pear- shaped bag, or pouch, capable of holding about two quarts of liquid. When full, it is some twelve inches long, and four inches broad. It is placed across the upper part of the abdomen, direct- ly under the diaphragm, the larger end to the left side BILE. Fig. 41. — Section of Stomach. 1 It is important to remember, that, in swallowing, the food and drink do not simply /«// down the gullet. Their passage is controlled by the muscles in such a way that they grip successive portions swallowed, and pass them along. Even in swallowing a pill, there is the same process. The smaller the pill, the greater the difficulty in swallowing; because the muscles have more trouble to get the necessary grasp on it. Some of us have seen an acrobat or juggler stand on his head, and drink a glass of water, and even eat in this position. We see the same thing every day when we notice a horse or cow drinking from a pail of water on the ground. When the food is pressed backwards by the tongue into the top of the gullet, it is no longer under the control of the will : it Is impossible to recall the mass, and it is necessarily carried into the stomach. 102 YOUNG FOLKS PHYSIOLOGY The stomach has two openings. The opening, or ring, through which the food enters, and where the gullet ends, is called the cardiac orifice. The other, at the right end, where the intestines begin, and that by which food leaves the stomach, is called the pylorus, or gate-keeper. The walls of the stomach consist of three coats : (i) A tough outer coat of fibrous tissue, which protects and strengthens the organ ; (2) a coat of smooth, or involuntary, muscular fibre, which rolls the food about in the process of digestion, with that wave-like motion which we noticed in describing the gullet ; (3) a third or inner coat, in which the blood-vessels and nerves are spread out. This inner or mucous coat is next to the food, and has its surface honeycombed with millions of little pits. We have all seen this in tripe. In the floor of each of these tiny pits a number of tubes open. These tubes, during the process of digestion, are constantly pouring into the stomach a peculiar fluid, called the gastric juice. The gastric juice is a clear, almost colorless, fluid, with a sharp acid taste. It contains a peculiar substance called pepsin, and an acid, both of which are necessary to the digestion of food in the stomach. The amount of gastric juice has been variously estimated, — all the way from five to fourteen pounds daily. There is com- paratively little in the stomach at any one time. There is no loss, for it is rapidly re-absorbed by the blood. Now, the moment the food reaches the stomach, the gastric juice begins to flow, the muscles begin to con- tract, and the whole organ takes on a churning motion. DIGESTION 103 The food is rolled over and over, and thoroughly mixed with the gastric juice. Two rings, one at the entrance and the other at the outlet, keep the food in the stom- ach while it is being churned about and digested. The gastric juice has scarcely any effect on the starchy matters, but acts on the albumens, such as are contained in meat, cheese, eggs, etc., to make a com- plete solution. Fig. 42. — The Stomach, showing its outer layers of muscular fibres. Some of these dissolved albumens, together with some of the starchy matters dissolved by the saliva, are at once sucked into the blood by the blood-vessels in the walls of the stomach. The remainder of the mass, a thick, pulpy, soup-like substance, resembling gruel, is I04 YOUNG folks' PHYSIOLOGY called chyme, meaning juice, with an acid odor and taste. Chyme contains more or less albuminoid matters, together with the starchy elements which have not been changed into sugar, and all the fat. The fat may be seen floating in large drops on the surface of the chyme. The ring at the outlet, or pylorus, now relaxes ; and the partially digested food is forced in little jets into the duodenum, or first part of the small intestines. 88. Digestion in the Intestines. — The intestines con- sist of a long tube, or canal, which fills the greater part of the abdomen. They are divided into the small intes- tines, about twenty-five or thirty feet long, and the large intestines, five or six feet in length. -To get all this into the small space it has to occupy, it is doubled upon itself many times. The first portion of the small intes- tines,^ which is directly continued from the stomach, is called the duodenum, because its length is about equal to the breadth of twelve fingers. Let us now see what goes on in the duodenum. Two pipes, or ducts, unite, and enter it. One comes from the gall-bladder, and brings the bile ; the other from the pancreas, and brings the pancreatic juice. These two tubes unite, and enter the duodenum at the same place. The liver is the large reddish-brown organ situated just under the diaphragm, and on the right and upper side of the abdomen. It is the largest organ in the body, and weighs about five pounds. The liver secretes 1 The small intestine includes three parts,— duodenum, jej-unum, and ileum. The large intestine includes the colon, ccEcum, and rectum. DIGESTION 105 from the blood a greenish fluid called the bile. It is stored up in a kind of little pear-shaped bag attached to the liver itself, and called the gall-bladder. The bile is a thin, greenish-yellow, bitter fluid. Some- times it is olive-brown in color ; but, when acted upon by the gastric juice, it takes on a distinctly yellow or greenish' hue ; hence the appearance of vomited bile. The chief use of the bile is to digest the fatty parts of the food, upon which the gastric juice does not act. The bile also aids in separating the nutritious from the useless parts of the food.^ The pancreatic jaice is very much like saliva. It is secreted by a long, narrow, flattened gland called the pancreas, or sweet-bread, which lies deep in the cavity of the abdomen, just behind the stomach. It is often said to resemble a dog's tongue in shape. The pancreatic juice finishes the work which the saliva began. It acts chiefly upon the starchy matters of the food which have escaped the saliva, and changes them into sugar. At the same time, however, it follows up the work of the gastric juice, and dissolves any albu- mens which have not been dissolved in the stomach. The inner surface of the intestines also pours in a liquid called the intestinal juice; which, like the saliva, 1 Bile is an alkaline fluid ; that is, it has the properties of baking-soda. We have tried, perhaps, to clean a bottle which has held oil. We put in some soda and warm water, and then shake the bottle. The soda breaks up the oil into tiny drops, which float round the creamy mixture. This is exactly what the bile does with the fatty parts of the food. In other words, it makes an " emulsion." Cod- liver oil is often mixed with other things to disguise the fishy taste. This creamy mixture, known as an " emulsion of cod-liver oil," is a familiar sight in the drug- stores. I06 YOUNG folks' PHYSIOLOGY acts upon the starchy matters. At the same time, how- ever, this juice acts as a solvent on any albuminoid matters or fats still undissolved. In fact, this intestinal juice has the properties of saliva, gastric juice, bile, and pancreatic juice, all in one. Like a prudent housekeeper. Nature intends that this last digestive fluid in the digestive tube shall act upon all matters in the intestines still left undissolved by the other juices, so that no part of the food may be wasted. • The chyme thus acted upon by these different fluids has the appearance of a thick cream, and is called chyle. The muscles of the intestines, like those of the stomach, are almost continually at work. The whole intestinal tube is constantly moving in a manner some- what resembling the motions of a worm ; and, all this time, it is squeezing and forcing forward its contents. In this way, the whole of the food is acted upon by every part oiF the intestines. 89. Absorption. How the Blood feeds on the Food. — The soup-like mass which left the stomach under the name of chyme, has now been changed into a thick cream called chyle. Squeezed slowly along the intes- tines by the worm-like twistings of the muscular walls, most of the nutritious parts of this milky fluid is sucked up drop by drop by the lacteals, and poured into the current of the blood. The process by which the di- gested materials are taken into the blood is called absorp- tion. This is done chiefly by two sets of vessels, — first, by the lacteals, or lymphatics ; second, by the blood-vessels. DIGESTION 107 90. Absorption by the Lacteals and Lymphatics. — The inner surface of the intestines is not smooth and shiny, like the outside, but shaggy, or, rather, has a vel- vety appearance. This is because the inner lining is crowded all over with millions of little tags, like very small tongues, hanging down into the inside of the intestines. These hair-like projections are called villi, meaning "tufts of hair." They are tiny affairs, about one-thirtieth of an inch long; and a five-cent piece would cover five hundred of them. These give the appearance of the pile on velvet. We are, of course, familiar with this appearance in tripe. In each one of these villi is a network of the finest blood-vessels, and a tube, or canal, ca,lled a lacteal, so called from a Latin word meaning "milky," and because it carries a white, milky fluid. Millions of these lacteals dip down into the intestines, like little root-fibres, and suck up from its creamy contents the fatty matters of the chyle. The lacteals, after passing through a number of glands — like way-stations on a railroad— in the abdo- men, unite into larger tubes, and finally open into a little sac, or bag, in the loins, called the receptacle of the chyle. Leading upward from this is a tube called the thoracic Fig. 43. — Two Villi (magnified). io8 YOUNG FOLKS PHYSIOLOGY duct, which carries the fluid upwards, along the back- bone, and pours it into a vein in the neck. The. tho- racic duct is about eighteen inches long, and about as large as a goose-quill. It acts as a feeding-pipe, to empty the nutritive matter absorbed from the food into iracTioN or 9RACIC DUCT WITH rSUBCLAVlWVElH Fig. 44. — Lacteals ending in Thoracic Duct, which empties into a Vein in the Neck. the blood-current. The lacteals are merely lymphatics, which begin in the villi of the intestines. In all parts of the body, except the brain, spinal cord, eyeball, and tendons, we find thin-walled vessels busily DIGESTION 109 at work, taking up, and making over anew, waste fluids or surplus materials derived from the blood and tissues generally. They seem to start out of the part in which they are found, like the rootlets of a plant in the soil. The tiny roots join together, and make larger roots. They carry a colorless fluid called lymph, very much like blood without the red corpuscles. The tubes in which this fluid flows are called lymphatics. These tubes have rounded bodies at many points of their course, scattered like depots along a line of railroad, called lymphatic glands. They seem to be fac- tories to make over the lymph in some way, and to fit it for renewing the blood. Most of the lymphatics at last unite with the lacteals, and empty their contents into the thoracic duct. Thus, again. Nature, like a careful housekeeper, uses up even the waste matters of our bodies, in providing them with nourishment. 91. Absorption by the Blood-vessels. — Soluble sub- stances can pass through the delicate walls of the blood- vessels. The inner lining of the digestive canal, es- pecially the small intestines, is rich in blood-vessels. The Spleen. — The spleen is a reddish, soft, and pulpy organ. It is about five inches in its longest diameter, and an inch thick, and situated near the left end of the stomach, just under the ninth, tenth, and eleventh ribs. The use of this organ is not known. It has probably something to do with the formation of blood-corpuscles. In certain diseases, like malarial fever, it may reach an enormous size. Two other glands, the /hyniiis and thyroid i^laiuis, known in the markets as the " breast sweet- bread " and "throat sweet-bread," are situated in the neck. They are regarded as appendages of the lymphatic system. Their use is not known. I lO YOUNG FOLKS PHYSIOLOGY Hence those parts of the food which have been made liquid, and capable of forming a soluble mixture with the blood, are absorbed directly by the small veins and capillaries ; although a small part finds its way into the lacteals. The emulsified fats, as we have seen, are mostly taken up by the lacteals. Certain materials, dissolved by the gastric juice and ingested liquids, are taken up directly by the blood-vessels of the stomach. An enormous absorbing surface is provided in the small intestines, by the arrangement of the mucous membrane in folds, and by the countless numbers of villi, which are con- stantly absorbing nutritive materials through the myri- ads of their tiny blood-vessels. It is important to remember that all the blood cir- culating in the digestive organs, and taking up the soluble nutritive matters, must pass through the liver before entering the general circulation ; and from it the liver selects and elaborates its secretion. 92. The large Intestines. — The large intestines begin at the lower extremity of the small intestines, and consist of three parts, the ascending, the transverse, and the descending colon ; the last of these being con- tinued into the rectum. This digestive tube, which is about six feet .long, first passes up the right side of the abdomen, then across under the liver and stomach, and, lastly, descends on the left side of the abdomen to the rectum. As the food-mass passes along into the large intestines almost everything which is fit to be taken up has been absorbed. Some digestion may go on in them, but it DIGESTION I I I is of little account. They are really a kind of passage- way, or temporary storehouse, for undigested and waste matter, which should be cast out of the body as speedily as possible. 93. How much to Eat. — The quantity of food needed to keep the body in good health varies very much according to circumstances. The general principles are these : Action is the law of every living being. Waste attends action : hence, in the main, the supply of food must equal the waste of the body. The greater the amount of exercise, the more food is called for to supply the waste. During the time of growth, a still greater quantity is needed to build up new tissues ; hence growing children generally have a good appetite and a vigorous digestion. The same holds good of persons getting well of some long and wasting sickness. The quantity required also depends very much upon one's business. Those who work hard and long, either with the body or mind, as teamsters, blacksmiths, farm- ers, doctors, and editors, need a goodly amount of nutritious food. Those who work in-doors, as clerks, milliners, students, and book-keepers, can get along with a smaller quantity. In cold weather, or in cold climates, a greater quantity of "fuel-food" is necessary than in warm weather or in a tropical climate.^ 1 Wonderful stories are told of the enormous appetite and craving for fat among the inhabitants of northern and the arctic regions. In the cold, dreary polar regions, the Esquimau consumes about twenty pounds of the blubber-fat daily, besides drinking several quarts of train-oil. This fat is as necessary as the fuel to keep his inward fire going, or he would perish from the bitter cold. Lamp-oil and candles are eaten by this people with as much zest as our children would relish ice-cream and l}ananas. The Cossacks, it is said, drank all the oil in the lamps, and left the streets of Paris in dark- ness, when the Allies entered the capital after the defeat of Napoleon. 112 YOUNG folks' PHYSIOLOGY An appetite for plain, simple, well-cooked food is a safe guide to follow. Every person in good health and with moderate exercise should eat well : he should have a keen appetite for his food, and enjoy it. Young, grow- ing, and vigorous persons should eat until appetite is fully satisfied, provided they have enough of exercise, both mental and bodily. It is easy to know when we are eating too much. An overworked stomach makes its condition known by a sense of fulness, uneasiness, drowsiness after meals, and sometimes a real distress. If we keep on eating too much and too rich food, the complexion is apt to be muddy, the face more or less covered with blotches and pimples, the breath has an unpleasant odor, and the general look of the face is dull and unwholesome. 94. What to Eat. — Food should be both nutritious and digestible. It is nutritious in proportion to its capacity to furnish suitable substances to be taken into the blood. Foods are digestible just as they are acted upon by the digestive fluids. Certain foods, as the vegetable albumens, are both nutritious and digestible. A man will grow strong and keep healthy on any of them.^ 1 The splendid races of Northern India live on barley, wheat, millet, and rice, as their staple food. In Soutliern India, millions of people live on pease and rice. There have been many generations of the hardiest men in the world in the north of England and Scotland, who lived on oat-meal and milk. These men literally lived their lifetime without taking any other food except green fruits, vegetables, and the cereals. The Roman gladiator was raised on barley ; and the Roman soldier endured his long marches and severe fighting on corn in boiled water, when meat could not be had. DIGESTION 113 We can safely eat some animal food every day, yet it is well to remember that the vegetable albumens supply all that is needed for the nourishment of the body. A strong, hearty person may ^t half a pound or so of meat daily ; yet he should take other foods, such as bread, oatmeal, beans, rice, and milk. These foods are all good, all cheap, all digestible, and all palatable. Vegetable foods are less stimulating than animal. Hence they are more suitable for children. Beef, pork, ham, oysters, and rich pastry should be sparingly given to children. The plainest and simplest diet is the best. It is much better for a child to go to bed on a supper of oatmeal, baked apples, or mush and milk, than warm bread, cake, pie, and fried meat. Parents cannot look too sharply after the food they give their children. This is especially important at the present day, when all kinds of strange devices are resorted to, to furnish the public with fanciful and tempting foods. Students must also look sharp to their diet. It is much better for them to begin a day's study with a breakfast of oatmeal, stale bread, a soft-boiled egg, and a glass of milk, than strong coffee, sausage, and hot biscuit. 95. When to Eat. — Three meals a day, from five to six hours apart, should be eaten. These should be arranged mainly according to one's occupation. The stomach, like other organs, does its work best when its tasks are done at regular periods. Hence, regularity in eating is of the utmost importance. Eating out of meal-times should be strictly avoided, for it robs the stomach of its needed rest. Food, 114 YOUNG FOLKS PHYSIOLOGY eaten when the body and mind are tired, is not well digested. Rest, even for a few minutes, should be taken before eating a full meal. It is a good plan to lie down, or sit qyietly and read, fifteen minutes before eating. Severe exercise and hard study just after a full meal, are very apt to check digestion. The reason is plain : after a full meal, the vital forces of the body are called upon to help the stomach digest its food. If they are forced, in addition to this, to help the muscles or brain, digestion will be hindered, and a feeling of dulness and heaviness follows. This, in time, often results in the common form of ill digestion called "dyspepsia." We should not eat for at least three hours before going to bed. When we are asleep, all the vital forces are at a low ebb, and digestion is difficult, if not impossible. We should make it a point not to omit a meal unless forced to do so. Children, and even grown-up people, often have the bad habit of going to school or to work in a hurry, without eating any breakfast. There is sure to be an "all-gone" feeling at the stomach before another meal-time. The state of the mind has a great deal to do with digestion. Sudden fear or joy, or unexpected news, may take away the appetite at once. Hence, so far as we can, we should laugh and talk at our meals, and drive away all anxious thoughts and unpleasant topics of discussion. If hunger is a good sauce, so also is a jolly laugh. 96. How to Eat. — Eat slowly, and thoroughly chew the food. Do not take too much drink with the food. DIGESTION I I 5 Our teeth were made to chew our food, and the saHva to moisten it, and help along digestion. If the food is well chewed, the saliva and the gastric juice act more readily. It is not only bad manners to eat rapidly, but it is a violation of the simplest law of digestion. If we take too much drink with our meals, the flow of the saliva is checked, and digestion is thus hindered. Rapid eating, with a great deal of drink to wash down the food, is almost sure to result in dyspepsia. Do not take the food and drink too hot or too cold. Such substances as very hot bread and coffee often injure the enamel of the teeth, and are slowly digested in the stomach. If the food and drink are taken too cold, undue heat is taken from the stomach, and diges- Proper Care of the Bowels. — Irregularity in eating, too much finely-bolted flour, and not enough fruit and . vegetables, rich pastry, negligence or carelessness in attending to a regular daily evacuation of the bowels, lead to the very common and distressing trouble known as constipation, or costiveness. As we grow older, this trouble generally grows worse. Many persons resort to all kinds of patent pills and medicines, which, for the most part, act only for the time, and do not remove the cause of the ailment. Such remedies do a deal of harm after a time, and are almost sure to leave the bowels in a worse condition. We must pay strict attention to the proper action of the bowels. The formation of a regular habit is of the utmost importance. The bowels can be trained to act at a certain time every day. Take great pains to eat coarse food, such as oatmeal, corn-bread, vegetables, stewed prunes, dates, figs, etc. Drink a glass of water just after getting out of bed in the morning. Rochelle or Seidlitz powders maybe needed at times; they are safe, and will do no harm. Vigorous muscular exercise, espe- cially kneading the muscles of the abdomen, is a valuable help. If these things do no good, consult a physician before purgative medi- cines are used in a hap-hazard sort of way, simply because some friend urges their use. Il6 YOUNG FOLKS PHYSIOLOGY tion delayed. The natural temperature is about ioo° F. If we drink freely of ice-water or cold well-water, its temperature will fall about 30° ; and it will take half an hour or more for the stomach to regain its natural heat. Drinking freely of very cold water when the body is heated is a dangerous practice, and, aside from its ill effects on digestion, has occasionally resulted fatally. It is a poor plan to bolster a flagging appetite with highly- spiced food and bitter drinks. An undue amount of pepper, mustard, horse-radish, pickles, fancy meat- dressings, and highly-seasoned sauces, may stimulate digestion for the time, but, used in excess, they soon weaken it. 97. The Proper Cooking of Food. — To prepare, cook, and serve food well, is a fine art. To voluntarily leave this important work to raw and untrained servants, is an evidence of false notions, and of a neglected or one- sided education. A knowledge of the principles and practice of cook- ing should form a part of every young person's educa- tion. Many an unhappy home is due to the neglect of the orderly and cleanly housekeeping and good cooking that raises the housekeeper to the dignity of the home^ maker. Many a man has been led into taking alcoholic drinks to quiet a craving caused by his system being imperfectly nourished. He is really hungry, not be- cause of any lack in the quantity of his food, but because of its poor quality. Many a constitution that might otherwise have been sufficiently strong and healthful to meet the demands DIGESTION 117 of life, has been ruined ; and dyspepsia and other forms of indigestion have resulted from the use of fatty, fried, soggy, heavy, and otherwise unwholesome food due to poor cooking. Every young woman who goes into a home of her own, from the office, shop, factory, or any position or occupation where she has had little or no practice in cleanly, orderly housekeeping, including good cooking, should take a special course of instruction in these mat- ters so important to the health and welfare of a house- hold. 98. Care of the Teeth. — The care of the teeth is an important matter. It is our duty to take the very best care of them, and to keep them as long as possible. Teeth are prone to decay. We may inherit poor and soft teeth : our ways of living may make bad teeth worse. If an ounce of prevention is ever worth a pound of cure, it is in keeping the teeth in good order. They should be thoroughly cleansed night and morning with a soft brush and warm water. Castile soap, and some simple tooth-powder with no grit in it, may be occasion, ally used. Dentists say that we should always cleanse the teeth before going to bed. The brush should be used on the inner or back side of the teeth, as well as on the front side. The enamel once broken or destroyed is never re- newed. The tooth is left to decay, slowly but surely : hence we must be on our guard against certain things which may injure the enamel. Picking the teeth with pins and needles is hurtful. We should never crack Il8 YOUNG FOLKS PHYSIOLOGY nuts, crush hard candy, or bite off stout thread with the teeth. Metallic tooth-brushes, gritty and cheap tooth- powders, and hot food and drink, often injure the enamel. We should never use any of the tooth-powders and washes, especially advertised and secret preparations, warranted to harden the gums, and whiten the teeth. Dirty and decayed teeth are a frequent cause of an offensive breath and a foul stomach. We should exercise the greatest care in saving the teeth. The last resort of all is to lose a tooth by hav- ing it extracted. The skilled dentist will save almost anything in the form of a tooth. 99. Effect of Alcohol on the Stomach-Digestion. — Alcoholic liquors act as a mild or strong irritant of the stomach, just as they are taken, raw or diluted. Their habitual use leads to most distressing forms of stomach disease. 1 If we could look into the stomach, as Dr. Beaumont looked into the stomach of Alexis St. Martin,^ just after taking a drink of raw spirit, we should find that the inner surface would be bright red when the alcohol touched it, and far more so than after taking ordinary food. Alcohol irritates the lining of the 1 " Many cases of dyspepsia are due to alcohol, solely and wholly." — J. Mil- NER FOTHERGILL, M. D. " Nothing with such certainty impairs the appetite and the digestive power as the continued use of strong alcoholic liquids." — Pavy on " Food." 2 The process of gastric digestion was studied many years ago by Dr. Beau- mont and others, in the remarkable case of Alexis St. Martin, a French-Canadian, who met with a gun-shot wound which left a permanent opening into his stomach, guarded by a little valve of mucous membrane. Through this opening the lining of the stomach could be seen, the temperature ascertained, and numerous experi- ments made as to the digestibility of various kinds of food. DIGESTION 119 stomach, and dilates the tiny blood-vessels, just as brandy dropped into the eye would make it look red and watery. Alcohol, like any other irritant, also causes the gastric juice to flow, just as the eye, when injured, becomes flooded with tears. The power of the gastric juice to dissolve food is at the same time either greatly diminished or entirely destroyed. For, whenever alcohol comes in contact with gastric juice, the pepsin, without which it cannot digest food, is precipitated. This hinders digestion until the alcohol is sufficiently diluted with water drawn from the stomach to prevent further precipitation of the pepsin.-"- Thus an extra amount of useless work is thrown upon the glands and makes them less active. If this unnatural excitement of the glands of the stomach is kept up for some time, these glands become weakened, and the gastric juice is diminished in quantity and made poorer in quality. The result is alcoholic dyspepsia. It has even been found by drawing off the contents of the stomach with a siphon, during various stages of digestion when alcohol has been taken, that it entirely suspends the transformation of food while it remains in the stomach, and that only after the alcohol leaves the stomach does digestion go on at a fair rate. In the case of St. Martin it was observed by looking directly into his stomach that when a whole- some dinner was digesting in good order, a glass of gin arrested the process, which was not continued 1 See Note 12, page 368. I20 YOUNG folks' PHYSIOLOGY until after the alcohol had passed out of the stomach. Now, when this alcoholic irritant is poured into the stomach for days, weeks, and even for years, it is no wonder that the stomach becomes altered in its struc- ture.i There is a chronic inflammation of the inner coats: the walls of the stomach become thicker and harder, and traces of ulcerations are often found. Be- cause the stomach is unable to digest food properly, many other organs of the body suffer as a result. 100. Effect of Alcohol on the Liver. —The liver is pe- culiarly liable to diseases due to alcoholic liquors.^ When alcohol is taken up by the blood-vessels of the stomach, it is carried directly to the liver, and filtered through this great organ before it reaches the heart. This, as we have been told, is a part of the portal circulation. Hence the poisonous effects of alcohol are strongly marked in the liver, especially among hard drinkers, and in hot climates. The blood-vessels of the liver are overworked, and the capillaries engorged with blood. This causes, first, 1 " The structural alterations induced by the habitual use of alcohol, and the action of this agent on the pepsin, seriously in:ipair the digestive power. Hence it is, that those who are habitual consumers of alcoholic fluids, suffer from dis- orders of digestion. Heartburn, water-brash, acid stomach, and a peculiar retching in the morning, are produced." — Robert Bartholow, M.D. " Alcohol in any appreciable quantity diminishes the solvent power of the gastric fluid so as to interfere with the process of digestion instead of aiding it." — W. B. Carpenter, M.D. " If the amount of alcohol be increased, or the repetition become frequent, some part of it undergoes acid fermentation in the stomach, and acid eructations or vomitings occur. With these phenomena is associated catarrh of the stomach and liver with their characteristic symtoms — loss of appetite, feeble digestion, sallowness, mental depression, and headache." — Dr. James C. Wilson. 2 See Note 13, page 369. DIGESTION 121 an enlargement of the liver, and then a shrivelling of the substance of the organ, together with a rough and " bunchy " surface. This, in medical language, is called cirrhosis^ meaning tawny, or orange-colored, but in common phrase gets the name of " hob-nail " or " gin- drinker's" liver, from its appearance.^ Again, fatty decay (called fatty degeneration), due to alcohol, may take place in the liver : this makes the organ of great size, sometimes weighing from fifteen to twenty pounds ; and one case is related of a drunkard's liver that weighed fifty pounds. loi. The Effect of Tobacco on Digestion. — The use of tobacco, either in smoking or chewing, causes the glands of the mouth to send out large amounts of saliva ; this, in time, weakens them and causes dryness of the throat. It also interferes with digestion.^ Very fre- quently smoking leads to indigestion, which can only be cured by abandoning the tobacco.* 1 " Cirrhosis of the liver is notoriously frequent among drunkards, and is in fact almost, though not absolutely, confined to them." -Robert T. Edes, M.D. ^ " Alcohol acts on the liver by producing enlargement of that organ, and a fatty deposit, or " hob-nailed " liver mentioned by the English «rriters." — W. B. CARPEtJTEK, M.D. 8 " Tobacco impairs digestion, poisons the blood, depresses the vital powers, causes the limbs to tremble, and weakens and otherwise disorders the heart. Physicians meet with thousands of cases of dyspepsia connected with the use of tobacco in some one of its forms." — Dr. Mussey. < See Note 14, page 371. YOUNG FOLKS PHYSIOLOGY CHAPTER VIII THE BLOOD AND ITS CIRCULATION 102. Uses of the Blood. — Every child knows, that if he cuts or scratches his finger, or even pricks it with a pin or needle, blood flows. What is true of the finger, is also true of every other part of the body, except the hair and nails. The tiny blood-vessels go everywhere, through the muscles and nerves, over and within the brain, through every particle of every bone, — the blood flows every- where. Every little bit of bodily tissue is bathed with the blood. The blood makes everything common as it flies from spot to spot. Wherever it goes, it has some- thing to bring, and something to carry away. The blood lives on the food we eat, and the tissues live on the nutritive material from the blood. The blood, in its ceaseless round, not only brings new material for repair, but it is also a kind of sewer-stream that drains off waste matters, and carries them to organs whose duty it is to cast them out of the body. 103. How Blood is made up. — Blood, as it is drawn from the body, is a red, somewhat sticky, fluid, thicker than water, and apparently all of one substance. It is not so simple a fluid as it looks. If we let fall a small drop of freshly drawn blood upon a piece of glass, and exam- ine it under a microscope, we shall see that this fluid is not all of one substance. It consi.sts of an almost color- THE BLOOD AND ITS CIRCULATION 1 23 less fluid called the plasma, and an enormous multitude of little bodies called corpuscles, floating in the liquid. These corpuscles are of two kinds, red and white.^ 104. Blood Corpuscles. — The liquid blood, which looks to the naked eye as if it were perfectly red, is, in reality, not red at all, being nearly ^^a ^ a as white as water. The red color is eMsv . li ® due to millions of little red corpus- d ^^ ^ MMK^ cles which float about in the blood. * • g)"™^ They are so closely packed, that OO W^U the blood, as a whole, looks uniform- ^ <^ ly red. In the same way, a clear fig. 45.— Human Bbod-giob- white glass bottle, filled with red ^J'sVerfrl"'he Tide''' Quilted beads and water, would look in rouleaux ; rf, rendered sphen- . - . . cal by water ; e, decolorized by uniformly red at a short distance, the same; /, Biood-giobuies Imagine a small brook all alive shrunk by evaporation, with little red fishes, and it would give some idea how the red corpuscles make the blood appear red. The red corpuscles are by far the more numerous, there being about four hundred of them to one of the white corpuscles. In shape the red corpuscles are flattened circular disks, resembling somewhat pieces of coin. They have something of the shape of an India-rubber air-cushion when blown up with air. They are not hard and solid, 1 The total quantity of blood in the body is about one-thirteenth of the weight of the body. Hence a man of average size has from ten to twelve pounds of blood. Of this amount, water makes up nearly four-fifths : only about one-fifth consists of dry solids. The solids consist mainly of the corpuscles, the albumen of the serum, and fibrine. The blood also contains a small quantity of minerals and salts. The most im- portant are iron, potash, soda, phosphorus, and sulphur. These are all essential to healthy blood. 124 YOUNG folks' PHYSIOLOGY but resemble tiny pieces of red jelly rather than any- thing else. In size they are so very small, that, if we had fingers delicate enough to handle them, we could pack away some fifty thousand of them on the head of a pm. It is said that some five million of them will float round in a single drop of blood. Under the microscope, the flat sides of these disks stick to one another m rolls, piled together like so many gold dollars. ^m r. ^ jfe/^1^i}«yiribB sWteJa t^jspargjtjng from a watery fluid called PRACTICAL EXPERIMENTS 295 We have now divided the milk into three parts, — cream, curd, and whey. Cream is the fat ; curd is the casein, or nitrogenous part, which, when pressed and dried, is called cheese ; and whey is milk-sugar and mineral matter dissolved in water. These simple experiments show that milk contains flesh- forming, bone-making, and heat-giving materials, and that it contains these in the right proportions, especially for children. 37. To show Water, and the Minerals. — Water is too familiar a food for experiment. If water could be easily obtained from some iron or sulphur springs, it would be interesting to compare the taste with specimens of hard and soft water from the neighborhood. The mineral matter left from Experiment 4 shows the various kinds of lime and potash. An egg-shell is a familiar example of carbonate of lime. Various kinds of salt (forms of soda) can be obtained from any grocer. The white of an egg contains a little sulphur. Leave a silver spoon in it for a short time, and the sulphur will blacken it. EXPERIMENTS WITH ALCOHOL [Chapter VI. Page 8i.J Experiment 38. Alcohol, and how it looks. — Get at the drug-store a four-ounce white-glass bottle, and let the drug- gist fill it for you with the best alcohol. Have it tightly corked, and properly marked with a label gummed on the bottom of the bottle. To remember : Alcohol is a thin, colorless liquid, which looks like water. 2g6 YOUNG FOLKS PHYSIOLOGY 39. To show how Alcohol burns. — Turn a little alcohol into an old-fashioned fluid lamp. Light it, and note the character of the light and the heat. Put a white saucer or plate closely down on the flame for a few minutes. Note that the alcohol burns without soot, giving little light but great heat. Suggestion. — If a fluid lamp is not easily obtained, use a small kero- sene lamp without the chimney. A lamp good enough for simple experi- ments can be made out of a common mucilage bottle, using the hollow handle o£ the metallic brush for the wick. A piece of a bean-blower run through the cork of an empty horse-radish bottle, using a rolled piece of kerosene-wick for the wick, will also provide the necessary apparatus for an alcohol lamp. 40. To show that Alcohol and Water unite readily, with a Slight Decrease of Volume. — Use a test-tube which will contain one fluid ounce (eight teaspoon- fuls). Drop in thirty drops each of alcohol and water. Gum a strip of white paper four inches long and one-fourth of an inch wide to the side of the test-tube, bringing the lower end on a level with Fig. 88. {he sixty drops of fluid in the tube. Have the strip of paper marked off into inches and one- eighths of an inch. Drop water carefully into the tube until exactly two inches have been added, as shown on the graduated paper ; then drop in alcohol until exactly two inches more have been added. Shake the tube carefully, taking care not to spill any of the fluid. Note that the alcohol and water unite with a slight de-- crease of volume. PRACTICAL EXPERIMENTS 297 41. To show the Great Attraction of Alcohol for Water. — Tie tightly some thin membrane (like the coverings of the sausages sold in the markets) across the mouth of a bulb test-tube. Place the test-tube (bulb downward) in a goblet or beaker. Fill the bulb with alcohol, and pour pure water into the goblet or beaker (Fig. 95). The alcohol will soon rise in the tube, thus proving that alcohol has such a liking for water that it has caused the water to filter through the membrane. 42. To show the Origin of Alcohol in Fermented Liquors. — Take a common glass fruit-jar which will hold one pint. Fill the jar one-half full of water, and add molasses until it is of a deep-brown color. Add a teaspoonful of yeast or one-half of a yeast-cake. Cover so as to admit some air, and keep at a temperature of 70'^ F. for a day or two. Note the result : The mixture has the odor of alcohol. What has happened ? Why, the yeast (called a " ferment ") has changed the sugar of the molasses to alcohol. The pro- cess of changing is called " fermentation." 43. Take as before a common glass fruit-jar which will hold one pint. Fill it one-half full of sweet cider. Allow the liquid to stand exposed to warm air. After a few days, shake the jar and it will be found that the liquid has the peculiar odor of alcohol. Very minute ferments have changed the sugar of the sweet apple-juice to alcohol. If the liquid should be left exposed to the air, it would, after a time, change to vinegar, which is known by its sour, acid taste. 44. Use a fruit jar as before. Fill it one-half full of sweet or unfermented wine. Continue the experiment as ex- plained in Experiment No. 43. 45. Take two wide-mouthed bottles holding one pint each. Be able to connect the two bottles A and B, as shown 298 YOUNG folks' rHYSIOLOGY in Fig. 96. Let a glass tube run from bottle B, and empty into a glass jar (C). Use a little putty or sealing-wax to stop any leaks made by the tubing running through the corks. Fill the bottle A about one-half full of molasses. Add one yeast-cake which has been dissolved in water. Fill the bottle with water, and shake vigorously. Fill the bottle B nearly full of water. Keep the apparatus in a warm room for two or more days ; an even temperature of 75° to 80° F. will do. The pupil will note that the fluid in the bottle A soon begins to " work," and that a substance called the lees set- FlG. 89. ties to the bottom of the bottle. The water in Bottle B will pass up the tube and over into the glass jar C. Note also that there is a change in the smell of the liquid. By this change a gas has been formed which has forced the water in B over into the glass jar. This change is called fermen- tation. 46. To show the Presence of Alcohol in Distilled Liquors. — Heat hard cider or sherry wine in a large-sized test-tube over an alcohol lamp. Run a piece of glass tube, bent at right angles, through a cork which fits the test-tube ; let the other PRACTICAL EXPERIMENTS 299 end of the tube be fitted into the cork of a wide-mouthed bottle which is set into a basin of cold water to condense the steam. The resulting liquid has a marked odor and taste. It is stronger than the fermented liquid. This process is called " distillation," and the resulting liquid, " distilled liquor." Fig. 90. 47. Pour one-half of a pint of hard cider into a common tin coffee-pot. Fasten a piece of rubber tubing to the spout. Have the other end of the tubing run into a wide-mouthed bottle sunk into a basin of cold water. Cloths wrung out in ice-water may be wrapped round the bottle. Heat the cider in the coffee-pot by an alcohol lamp, placed as shown in Fig. 97. Do not allow the cider to boil. Note that the color and odor of the resulting liquor differ from the .color and odor of the hard cider. A stronger liquor has been produced by this process. This process is called distillation. The stronger liquor has been separated from the water. It may be necessary to re-distil the result- ing liquor several times before a liquor is found pure enough to burn. 300 YOUNG FOLKS PHYSIOLOGY 48. To show the Effect of Alcohol on Albumen. — Place the white of an egg in an empty quinine or horse-radish bottle. Pour in some strong alcohol. Stir with a spoon or glass rod. Note that the alcohol hardens, or coagulates, the albumen ; in other words, the alcohol has such a liking for the water of the albumen, that it withdraws it, leaving it hard. 49. Repeat the same experiment, using dilute alcohol (one- half alcohol and one-half water). 50. Place in the same kind of a bottle as before a small strip of raw beefsteak. Add strong alcohol, and let mixture be set aside for a few days. Note that the meat seems hard. The alcohol has coagu- lated the albumen of the meat. The alcohol withdraws the water of the fresh, elastic, muscular tissue, leaving it tough and hard. 51. Squeeze a piece of fresh beef in a lemon-squeezer over a wide-mouthed bottle. Pour in a little water ; stir it until well colored with blood. Add strong alcohol. Set aside for several days. Note that the liquid is full of white particles. The alcohol has coagulated the albumen of the blood. 52. Repeat the last two experiments, using dilute alcohol. Note the result after a few days. Take two bottles, into one of which some days before were placed weak alcohol and a piece of beef ; into the other, pure alcohol and beef. Take a piece of fresh beef, and you will find that it is as strong as a whip-cord. Now observe these pieces in the bottles. They are dry and brittle. They break like a piece of suet. 53. To show the Action of Alcohol on Pepsin. — Take two ordinary wide-mouthed bottles holding from a gill to half a pint {A and E). Put into the first bottle five grains of pep- sin and two or three ounces of lukewarm water. Make it acid with twenty drops of strong muriatic acid. PRACTICAL EXPERIMENTS 3OI Do exactly the same thing with the second bottle, except add three tablespoonfuls of alcohol. Set the bottles in any convenient place sufficiently warm (near a stove or on a mantel near a warm smoke-pipe) to keep the contents of the bottles at about blood-heat. After ten hours, note the changes, if any. The pepsin is precipitated in the form of white, stringy particles in the bottle containing alcohol, while the other bottle shows no change ; in other words, the alcohol has precipitated the pepsin of the artificial gastric juice. 54. Prepare the bottles exactly as before. To the bottle A add two teaspoonfuls of finely minced albumen. Put it in a warm place, as in Experiment No. 53. Shake very often. The pepsin will begin to act upon the albumen, gradually softening it. In actual digestion, albumen is thus made ready to soak through the moist lining of the stomach. Do exactly the same thing with the second bottle {B) except add three tablespoonfuls of strong alcohol. Expose the bottle to heat, as before. After ten hours, note the result. It will be seen that alcohol has coagulated the albumen in bottle £. 55. Repeat Experiment No. 54. Instead of the white of an egg, add a teaspoonful of finely cut, cooked, and lean beefsteak or corned beef. In the bottle A the meat will be more or less dissolved or partially digested in twenty-four hours. In the bottle B the effect of the alcohol will be to make the meat seem hard. In short, the alcohol has coagu- lated the albumen of the meat. 56. Repeat Experiments 53 and 54. Instead of alcohol, use strong beer, whiskey, and rum, to show the action of the more dilute forms of alcohol upon the various types of albumen. 302 YOUNG FOLKS PHYSIOLOGY 57. Repeat Experiment 41. Instead of plain water, add one-quarter of a teaspoonful of common salt to the given amount of water. This saline solution will represent, in a general way, the plasma of the blood. The alcohol will rise in the tube, as in Experiment 41. Now, if we use very dilute alcohol (one part of alcohol to ten parts of water), we find that the alcohol in the tube falls. In other words, when alcohol is sufficiently dilute, it will go towards the fluid representing the plasma of the blood. 58. To show how Alcohol coagulates the Blood. — Get your market-man to carry a clean wide-mouthed fruit-jar to the slaughter-house, and let the butcher fill it with fresh blood. Add at once to the fresh blood a heaping tablespoonful of Epsom salts dissolved in a coffee-cup full of water. This strong saline solution will prevent the formation of a clot. Keep the whole mixture in a cool place, and do not shake it. Draw off two ounces of the mixture, and add to it a pint of water. Set it aside. It remains clear. Dilute the same amount of the mixture with a pint of water, and pOur in a few tablespoonfuls of strong alcohol. Note that the blood is soon coagulated. 59. To show the Effect of Alcohol on the Blood Corpuscles. — Squeeze the end of the forefinger and pierce the skin quickly with a fine needle, drawing a drop of blood. Examine it carefully with a microscope. Note the little corpuscles, their shape, and how they are arranged. Add the tiniest drop of alcohol. The corpuscles shrink and become of a different or irregular shape. The alcohol has coagulated the albumen of the corpuscles. 60. To show the Effect of Alcohol on the Circulation of the Blood. — Stretch the web of a frog's foot over a hole in a thin board, as fully directed in Experiment No. 98. Do this carefully to avoid giving pain to the frog. PRACTICAL EXPERIMENTS 3O3 Note carefully the circulation of blood through the very small blood-vessels. Now put on the web a drop of dilute alcohol, and note the result. The little blood-vessels seem to stretch and to allow the blood corpuscles to pass through more rapidly. The alcohol has weakened the nerves which regulate the flow of blood in the capillaries, thus allowing more blood to flow through them. 61. Repeat the preceding experiment. Instead of dilute use strong alcohol. Note that the capillaries soon shrivel, and the flow of blood stops. The alcohol in this case has paralyzed the nerves which control the capillaries. The tiny blood-vessels now contract, and stop the flow of blood. EXPERIMENTS ON DIGESTION [Chapter VII. Page 92.J 62. To show the Anatomy of Certain Organs, and Parts of Organs, of Digestion. — Have each pupil examine his own mouth, and also that of some friend. Note the lips, tongue, hard palate, soft palate, uvula, tonsils, and upper part of the gullet. 63. The Teeth. — Get a specimen of each kind of tooth if possible. A dentist-friend will give you what you need. Use a very fine saw to saw a perfect molar in two lengthwise. If need be crack the tooth with a hammer. Note its structure in a general way, — its crown, body, cusps, roots, enamel, dentine, pulp-cavity, etc. 64. Make a blackboard-sketch of a tooth on a large scale, using colored crayon to make plain the various parts of a tooth. 304 YOUNG FOLKS PHYSIOLOGY CROWN/ 65. To show the Difference of Teeth in Various Animals. — Get, if possible, specimens of teeth of the more familiar animals,' as the cat, dog, rat, squirrel, etc. Compare them with the specimens of human teeth. 66. With the help of a mirror, let each pupil locate his own teeth. Note the incisors, eye-teeth, bicuspids, molars, and " wisdom " teeth if any. In the same way, note the teeth of some schoolmate. 67. Locate as near as possible the position of each salivary gland. Press on the part of the cheek opposite the second small molar of the upper jaw, and notice the increased flow of saliva. The appearance of saliva is familiar. 68. To show Location of Other Or- gans of Digestion. — Make a black- board diagram, in the rough, of the organs of digestion, beginning at the cardiac end of the stomach, after hav- ing studied the digestive organs on the chart. Map out on the person in a very general way the location of the stomach, small intestines, and the colon, liver, pancreas, and spleen. The location of the stomach and liver is especially important. 69. To show how the Wall of the Stomach looks. — The wall of the pig's stomach resembles the human stomach. Get from the market a piece of a pig's stomach. Cut off bits of it, and examine it thoroughly. Scrape off the inner or mucous coat with the edge of a very sharp knife. 1 No stress is laid in this book upon the subject of " comparative anatomy." Many valuable points can be given orally by the painstaking teacher. For refer- ence, consult Mivart's Lessons on Elementary Anatomy. OOATl*** Fig. gi. — Blackboard Sketch. Section of a Tooth. PRACTICAL EXPERIMENTS 305 Use a magnifying-glass ; find the openings of the gastric tubes. Pick with fine needles, and note the muscular coats. Contrast tiie pig's stomach with that of a cow's by examining a piece of tripe. 70. To make the Saliva flow. — Think of some favorite article of food (both at the time you are hungry and when you are not), and note the flow of saliva. Push a lead-pencil or the finger to and fro in the mouth several times, and note the flow of saliva. Chew an oyster-cracker, and note carefully how it is moistened with saliva. Grind up several crackers rapidly in the mouth. Note how difficult it is to swallow, or even chew, when there is little saliva. 71. The importance of the saliva in favoring the movements of chewing may be illustrated by the experiment of wiping the inside of the mouth perfectly dry with a towel or handker- chief ; when it will be found almost impossible to move the jaws until the saliva is again secreted in sufficient quantity to moisten the surface of the tongue, cheeks, and gums. 72. The importance of the saliva as a solvent may be shown by wiping the upper surface of the tongue quite dry with a nap- kin, and then placing a small quantity of powdered sugar upon it. The sugar will be found to be as destitute of taste as so much sand ; whereas in its ordinary moist condition the tongue perceives the taste of sweet substances very distinctly. This experiment also illustrates the fact that the termina- tions of the nerves of taste can be affected only by sub- stances brought in contact with them in the liquid state. 73. To show the Action of Saliva on Starch. — Chew slowly a piece of fresh bread.i Note how sweet it tastes after 1 Chew pieces of the brown crust of the bread. It is quite sweet, and readily dissolves ; because, exposed to more heat than the rest of the loaf, the starch has been changed into dextrine before the bread left the oven. Hence, crust and toast are favorite articles of food, especially with old people. 3o6 YOUNG folks' physiology it is well wet with the saliva. Do the same with a mouthful of paste made of pure arrowroot (almost pure starch), made with boiling water, and allowed to cool. 74. Take three test-tubes. Into test-tube No. 1, half full of cold water, add some half a dozen drops of the arrow- root paste ; now add one of Fehling's Test-Tablets.^ Mix thoroughly, and boil over a spirit-lamp. There is no turbid brick-red deposit to show that there is sugar in the starch (arrowroot). 75. Put several teaspoonfuls of saliva into test-tube No. 2. Dilute it with water. Add a test-tablet, mix thoroughly, and boil. There will be a violet color, but no brick-red deposit to show the presence of sugar in the saliva. 76. Take test-tube No. 3, and put a few drops of the starch paste into a teaspoonful of saliva, and fill the test-tube half-full of water. Put the mixture away for ten minutes in a warm place. Now add a test-tablet. Mix and boil. A turbid brick-red deposit will be thrown down, showing that sugar is present, due to the action of the saliva on starch. 77. To show the Action of Gastric Juice on Albumen. — Take an ordinary four-ounce bottle with as wide a mouth as convenient. Put into it the following : Pepsin in scales (Fairchild's),^ one grain, and four tablespoonfuls of luke- warm water. Make it acid with ten drops of strong muriatic 1 These tablets have been used of late as a convenient method for physicians to test for sugar. It is simply an easy way to use the test usually made with a solution of caustic potash and blue vitriol. 2 It is not at all necessary to go through the long process of getting pepsin from a pig's stomach. Pure pepsin, obtained from the stomach of the pig, is now made by dealers for medical use ; and the necessary amount can . be bought of a good druggist for a few cents. Use only purs pepsin in the experiments. The student is advised to use Fail-child's " Pepsin " and " Ex- tract of Pancreas." PRACTICAL EXPERIMENTS 3O7 acid. Add two teaspoonfuls of finely minced egg-albu- men.^ Set the mixture in any convenient place sufficiently warm, as in a basin of warm water, near the stove, or on the mantel near the warm smoke-pipe, to keep the contents of the bottle at about " blood-heat." ^ Shake every few minutes. As soon as the whole mixture becomes of a proper temperature, the pepsin will begin to act upon the albumen; and it may be seen to be gradually softened and digested. This dissolved mass is now in a condition to readily soak through the moist lining of the stomach, and is known as " peptone." 78. Repeat the same experiment, using half a teaspoonful of finely cut, cooked, and lean beefsteak or corned beef in- stead of the white of an egg. The meat will be more or less dissolved, or partially digested, in twenty-four hours. This is only a crude way to show the action of gastric juice on meat-albumen. 79. Get some freshly drawn blood. Whip it with twigs. Pull off the collected fibrine, and wash it carefully in clean water. Save this in dilute alcohol, and use it as a handy albumen for digestive experiments. Repeat as directed in Experiments 77 and 78. 80. To show the Action of Bile on Fat. — Shake up a little sweet-oil and water. "Oil and water will not mix," as the saying goes. Get the butcher to bring you a small ' The albumen or the white of an egg is taken as the type of albumen in a naturally pure state, and is well adapted to illustrate the peptonizing action of the gastric ferment. It should be first made ready as follows: Separate the white of a hard-boiled egg, and rub it through a coarse sieve, so as to divide it into small particles. 2 In these experiments on digestion, the temperature should never be below blood-heat, and never allowed above a point at which fluids can be easily borne by the mouth. 3o8 YOUNG folks' physiology bottle of bile (ox-gall), or, better still, ask him to bring the gall-bladder itself. Cut it open, and bottle the contents. Shake up some oil with bile, and a creamy mixture called an " emulsion " results. 8 1. To show the Action of Pancreatic Juice upon Oils or Fats. — Put two grains of Fairchild's Extract of Pancreas into a four-ounce bottle. Add half a tablespoonful of warm water, and shake well for a few minutes ; then add a table spoonful of cod-liver oil ; shake vigorously. A creamy, opaque mixture of the oil and water (called an " emulsion ") will result. This will gradually separate upon standing, the pancreatic extract settling in the layer of water at the bottom. It will again form an emulsion when shaken. 82. To show the Action of Pancreatic Juice on Starch. — Make a smooth starch paste, just as the laundress does in starching her clothes. Put two tablespoonfuls of this paste into a goblet or tumbler, and, while still so warm as to just be borne by the mouth, stir into k two grains of the Extract of Pancreas. The starch paste will at once become thinner, and gradually changed into soluble starch, in a perfectly fluid solution. 83. To show the Action of Pancreatic Juice upon the Albu- minous Ingredients (casein) of Milk. — Into a four-ounce bottle put two tablespoonfuls of cold water ; add one grain of Fairchild's Extract of Pancreas, and as much baking-soda as can be taken up on the point of a penknife. Shake well, and add four tablespoonfuls of cold, fresh milk. Shake again. Now set the bottle into a basin of hot water (as hot as can bear the hand in), and let it stand for about forty-five minutes. While the milk is digesting, take a small quantity of milk in a goblet, and stir in ten drops or more of vinegar. A thick curd of casein will be seen (see Exper. 36). PRACTICAL EXPERIMENTS 3O9 Upon applying the same test to the digested milk, no curd will be made. This is because the pancreatic ferment (called trypsin)^ has digested the casein into " peptone," which does not curd. This digested milk is therefore called " peptonized milk." 2 84. Study of the Liver, — The whole of a liver is rather an awkward and bulky thing to handle ; but it is a good plan to get a sheep's liver, and devote a little time to its gross anatomy. Take pains to get the liver with the gall-bladder unbroken. Having once secured a fine specimen, it may be kept for future use in dilute alcohol. 85. To illustrate the Principle of Absorption. — The manner in which absorbent vessels suck in juices may be illustrated in a general way as follows : Take a glass tube, and tie a piece of bladder, in the form of a small bag, at the end of it ; pour some mucilage into it, and then plunge the end into a cup or glass containing water. In a few moments the mucilage in the tube will begin to rise, and the water in the glass will sink ; because, being more dense than the water, it draws it in through the bladder, and will continue to do so until they are equal. Again, if we put mucilage into the glass, and fill the tube with water, the water will fall in the tube until they become of the same thickness. It is on this principle that the absorbent vessels suck in liquids which are thinner than what they previously con- tained. 1 The active principle of the sahva which acts upon starch is often spoken of as ptyalin, in order to distinguish it from the starch-digesting principle of the pancreatic juice. Both have the same action upon starch. Experiment 57 will also illustrate the action of saliva. 2 Infants, especially those brought up on artificial foods, often suffer from ill digestion, " summer complaint," and other intestinal troubles during hot weather. Partially digested, or peptonized milk is often found to be of the greatest ser- vice at such times. 310 YOUNG FOLKS PHYSIOLOGY EXPERIMENTS ON THE HEART AND THE CIRCU- LATION [Chapter VIII. Page 122. J Experiment 86. — Tie a string tightly round the finger, and pierce the tip of it with a needle. The blood runs freely, is red and opaque. Put a drop of fresh blood on a sheet of clean white paper, and note that it looks yellowish. 87. Put a drop of fresh blood on a clean white plate. Cover it with an inverted goblet or sauce-plate. Take off the cover in five minutes, and the drop has set into a jelly- like mass. Breathe into the goblet several times to moisten it, and replace it over the blood. Take it off in half an hour, and a little clot will be seen in the watery serum. 88. To show the Blood-Clot. — Carry a clean wide-mouthed bottle to the slaughter-house. A half-pound chloral bottle bought at any drug-store is the best. A clean horse-radish bot- tle will do. Fill it with fresh blood. Carry it home with great care, and let it stand over night. The next day the clot will be seen floating in the nearly colorless serum. 89. To show the Fibrine of the Blood. — Get a wide- necked bottle full of fresh blood. A pint or quart fruit-jar is the best for this purpose. Beat the blood vigorously for five minutes with some dry twigs, and hang them up to dry. Let the blood stand until the next day. Note that it has Fig. 92. — Blackboard Sketch. The Heart and its four rooms. PRACTICAL EXPERIMENTS 3" not clotted. Wash out the twigs thoroughly, and a stringy mass of elastic substance will be found hanging to them. This is the fibrine. 90. Take some of the serum saved from Experiment 88, and note that it does not coagulate of itself. Boil a little in a test-tube over a spirit-lamp, and the albumen will coagulate. 91. To show that blood is really a mass of red bodies, floating in a fluid, which give it the red color. Fill a clean white-glass bottle two-thirds full of little red beads, and then fill the bottle full of water. At a short distance the bottle appears to be filled with a uniformly red liquid. 92. To show the Blood Corpuscles. — A moderately power- ful microscope is necessary to examine blood corpuscles. Let a small drop of blood (which may be readily obtained by pricking the finger with a sharp needle) be placed upon a clean slip of glass, and covered with a piece of thin glass, such as is ordinarily used for mi- croscopic purposes. The blood is thus spread out into a film, and may be examined with the microscope. At first the corpuscles will be seen as pale, disk-like bodies float- ing in the clear fluid. After a time they will be observed to stick to each other by their flattened faces, so as to form rows. The color- less corpuscles are to be seen among the red ones, but they are rnuch less numerous. 93. To show how Blood holds a Mineral Substance in Solu- tion. — Put an egg-shell crushed fine into a glass of water made acid by a teaspoonful of muriatic acid. After an hour or so the egg-shell will disappear, having been dissolved in Fig. 93. — Blackboard Sketch. The Heart and its great Blood-vessels. 312 YOUNG FOLKS PHYSIOLOGY the acid water. In like manner the blood holds various minerals in solution. 94. To show the Sounds of the Heart. — Locate the heart exactly. Note its beat. Borrow a stethoscope from some physician. Listen to the heart-beat of some friend. Note the sounds of your own heart in the same way. 95. To find the Pulse. — With your right hand grasp the right wrist of a friend, pressing with three fingers over the radius. Press three fingers of your right hand over the radius in the left wrist, to feel your own pulse. With the aid of a watch, count the rate of your own pulse per min- ute. Do the same with a friend's pulse. 96. To show how the Pulse may be studied by J-,, , \ // I I I '"v pressing a Mirror over the I \ \\/ I J )^^-^ Radial Artery. — Press a y ^-^ / / / small piece of looking- glass upon the wrist over the radial artery in such a way that with each pulse-beat the mirror may be slightly tilted. If the wrist be now held in such a position that sunlight will fall upon the mirror, a spot of light will be reflected on the opposite side of the room, and by its motion upon the wall will be shown the movements of the artery as the pulse-wave passes through it. — Bowditch's " Hints for Teachers of Physiology." 97. Dissection of a Sheep's Heart. — Get a sheep's heart with the lungs attached, as the position of the heart will be better understood. Let the lungs be laid upon a dish so Fig. 94. — How the Pulse may be studied by pressing a Mirror over the Radial Artery. PRACTICAL EXPERIMENTS 313 that the heart is uppermost, with its apex turned towards the observer. The'line of fat which extends from the upper and left side of the heart downwards and across towards the right side, indicates the division between the right and left ventricles. Examine the large vessels, and, by reference to the text and illustrations, make quite certain which are the aorta, the pulmonary artery, the superior and inferior vence cava, and the pulmonary veins. Tie variously colored yarns to the vessels, so that they may be distinguished when separated from the surrounding parts. Having separated the heart from the lungs, cut out a por- tion of the wall of the right ventricle towards its lower part, so as to lay the cavity open. Gradually enlarge the opening until the chordm tendinece and the flaps of the tricuspid valve are seen. Continue to lay open the ventricle towards the pulmonary artery until the semilunar valves come into view. The pulmonary artery may now be opened from above so as to display the upper surfaces of the semilunar valves. Remove part of the wall of the right auricle, and examine the right auriculo-ventricular opening. The heart may now be turned over, and the left ventricle laid open in a similar manner. Notice that the mitral valve has only two flaps. The form of the valves is better seen if they are placed under water, and allowed to float out. Observe that the walls of the left ventricle are much thicker than those of the right. Open the left auricle, and notice the entrance of the pul- monary veins, and the passage into the ventricle. The ventricular cavity should now be opened up as far as the aorta, and the semilunar valves examined. Cut open the aorta, and notice the form of the semilunar valves. 314 YOUNG FOLKS PHYSIOLOGY g8. To show the Circulation in a Frog's Foot. — In order to see the blood circulating in the membrane of a frog's foot it is necessary to firmly hold the frog. For this purpose obtain a piece of soft wood, about six inches long and three wide, and half an inch thick. At about two inches from one end of this, cut a hole three-quarters of an inch in diameter, and cover it with a piece of glass, which should be let into the wood, so as to be level with the surface. Then tie up the frog in a wet cloth, leaving one of the hind-legs outside. Next, fasten a piece of cotton to each of the two longest toes, but not too tightly, or the circulation will be stopped and you may hurt the frog. Tie the frog upon the board in such a way that the foot will just come over the glass in the aperture. Pull carefully the pieces of cotton tied to the toes, so as to spread out the membrane between them over the glass. Fasten the threads by drawing them into notches cut in the sides of the board. The board should now be fixed by elastic bands, or by any other convenient means, upon the stage of the microscope, so as to bring the membrane of the foot under the object- glass. The flow of blood thus shown is indeed a wonderful sight, and never to be forgotten. The membrane should be occa- sionally moistened with water. Care should be taken not to occasion any pain to the frog. EXPERIMENTS ON THE LUNGS AND BREATHING. [Chapter IX. Page 142 .J Experiment 99. To locate the Lungs. — Mark out the boundaries of the lungs by " sounding " them ; that is, by percussion as it is called. It simply means, to put one fin- ger across the chest or back, and to give it a quick, sharp PRACTICAL EXPERIMENTS 315 rap with another. Note where it sounds hollow ; that is, is resonant. This experiment can be done only in a very crude way. 100. Borrow a stethoscope, and listen to the respiration directly below the collar-bones. Note the difference in in- spiration and expiration. 1 01. Get a sheep's lungs, with the windpipe attached, from a butcher or marketman. Ask for the heart and lungs all in one mass. Take pains to examine the specimen first, and pay only for a good one. Parts are apt to be hastily snipped or mangled. 102. Examine the windpipe. Note the horseshoe-shaped rings of gristle in front, which serve to keep it open. 103. Examine one bronchus, carefully dissecting away the lung-tissue with curved scissors. Follow along until small branches of the bronchial tubes are reached. Take time for the dissection, and save the specimen in dilute alcohol. Put pieces of the lung-tissue in a basin of water, and see if they float. 104. To show how the Lung may be filled with Air. — Take the other lung, and tie a glass tube six inches long into its bronchus. Attach a piece of rubber to one end of the glass tube. Now blow up the lung, and then let it collapse several times. When distended, examine every part of it. 105. To show the Diaphragm. — Dissect a rat or kitten, and cut out a section of the body large enough to show the diaphragm and its attachments. The parts can be neatly held in place by pins and silk threads, and the whole kept in dilute alcohol. 106. To show the Vocal Cords. — Get a pig's windpipe in perfect order from the butcher, to show the vocal cords. Once secured, it can be kept for an indefinite time in alcohol. 3i6 YOUNG folks' physiology 107. To show that the Air we breathe out is warm. — Breathe on a thermometer for a few minutes. The mercury will rise rapidly. 108. To show that it is moist. — Breathe on a mirror, or a knife-blade, or any polished metallic surface. 109. To show that the Air we breathe out contains Car- bonic Acid. — Put a glass tube into a bottle of lime-water, and breathe out into it through the tube. The liquid will soon become cloudy, because the carbonic acid of the ex- pired air throws down the lime held in solution. 1 10. To show the Natural Temperature of the Body. — Bor- row a physician's thermometer, and take your own tempera- ture, and that of several friends, by putting it under the tongue, closing the mouth tightly, and holding it there for five minutes. 111. "A substitute for a clinical thermometer may be readily contrived by taking an ordinary house thermometer from its tin case, and cutting off the lower part of the scale so that the bulb may project freely. With an instrument thus arranged, the pupils may take their own and each other's temperature ; and it will be found that whatever may be the season of the year or the temperature of the room, the ther- mometer in the mouth will record about 99° F. Care must, of course, be taken to keep the thermometer in the mouth till it ceases to rise, and to read it while it is still in position." — Prof. H. P. Bowditch. EXPERIMENTS ON THE SKIN [Chapter X. Page 161. J Experiment 112. To show the Gross Structure of the Skin. — Examine your own skin in a general way. Stretch and PRACTICAL EXPERIMENTS 317 pull it, to show how elastic it is. Get some idea of the scarf- skin by scraping off some with a sharp knife. Note any white scars, liver-spots, etc., on the skin. Exam- ine the skin with much care, with the aid of a good magni- fying-glass. Note the papillse on the palm of the hand. 113. Hair and Nails. — Pull a stout hair from the head, and examine it carefully with the magnifying-glass. Make a similar study of the finger-nails. 114. The Sweat-glands. — Use a magnifying-glass to study the openings of the sweat-glands, especially on the palms of the hands. EXPERIMENTS ON THE NERVOUS SYSTEM [Chapter XI. Page 177.J Experiment 115. I'o show the Brain and Spinal Cord. — It is a troublesome matter to dissect out the brain and the spinal cord of one of the smaller animals like the rat, rabbit, or cat. The back of the animal to be dissected should be turned upwards, and the limbs should be securely fastened to the top of a small table. The skin is removed from the head by making a longitu- dinal incision in it, and then turning it back upon each side. The muscles upon the sides and back of the skull should next be cleared away. A hole may now be made in the top of the skull with the point of a pair of scissors, and the bone broken away piece by piece, with a pointed pair of nippers, until the upper surface and sides of the brain can be seen. In the cat, kitten, or rabbit, the cerebral hemispheres do not, as in man, cover the cerebellum ; and consequently the latter is seen when the brain is viewed from above. When the bone has been broken away enough to expose 3i8 YOUNG FOLKS PHYSIOLOGY the sides of the brain, the latter should be carefully raised by inserting the tips of the fingers under it on one side, and gently pulling. Several white cords will thus be seen passing from the under surface of the brain to the floor of the skull : these are the cranial nerves. To expose the spinal cprd, the skin of the back must be removed, and the muscles cut away from each side of the backbone, as close to the bone as possible ; then, beginning at the back of the skull, the spinal canal is to be laid open by cutting with the nippers the two sides of each vertebra. Care must be taken not to cut or tear the spinal cord, or the nerves passing off from it. When the spinal cord has thus been exposed, and the membranes which surround it made out, the spinal nerves should be examined. The brain and spinal cord should now be removed, by carefully lift- ing them, and cutting off the nerves by which they are attached. The specimen should now be neatly fastened to a thin strip of smooth pine-wood, and firmly held in place with pins. The whole can be kept in alcohol and water. Great patience is necessary to make the dissection a success. ii6. To show the Brain. — A sheep's or calf's brain is to be preferred, on account of its larger size. Get one fresh from the butcher. Pay him to .dissect away the skin and muscles of the skull, under your direction, and to saw open the cranium in a circular direction. Take time, and remove Fig. 95- — Blackboard Sketch. Showing the Position of the Brain. PRACTICAn, EXPERIMENTS. 3 I9 the sawed top with great care, tearing away the dura mater from the bones. Now cut away enough of this membrane so that the sides of the skull can be sawed and torn away, to allow us to lift out the brain, with proper dissection, in as perfect a state as need be. Put all the torn parts and membranes back into place. Put the whole aside to harden for three days in alcohol. Now we are ready to study its gross anatomy. Note the dura mater, the arachnoid lining it, and the pia mater closely attached to the brain. Find the cerebrum, or big brain, the cerebellum, or little brain, the medulla, and the stumps of the cranial nerves, especially the stumps of the optic nerves. The hardened brain should be first examined as a whole, and compared with the description given in the text, or the pictures of the human brain. 117. Sensations are referred to the Ends of the Nerves. — Strike the elbow-end of the ulna against anything hard (" hitting the crazy-bone ") where the ulna nerve is ex- posed, and the little finger and the ring-finger will tingle, and become numb. 118. Every Nerve is independent of atty Other. — Press two fingers closely together. Let the point of the finest needle be carried ever so lightly across from one finger to another, and we can easily tell just when the needle leaves one finger, and touches the other. 119. One Part of the Body works for the Good of another Part. — Tickle the inside of the nose with a feather. This does not interfere with the muscles of breathing ; but they come to the help of the irritated part, and provoke sneezing to clear and protect the nose. 120. To paralyze a Nerve temporarily. — Throw one arm over the sharp edge of a chair-back, bringing the inner edge of the biceps directly over the edge of the chair. Press 320 YOUNG FOLKS PHYSIOLOGY deep and hard for a few minutes. The deep pressure on the nerve of the arm will put the arm " asleep," causing numb- ness and tingling. The leg and foot often "get asleep" by deep pressure on the nerves of the thigh. EXPERIMENTS ON THE SPECIAL SENSES [Chapter XII. Page 210.] Experiment 121. — Cross the middle finger over the forefinger, and shut the eyes. Hold a marble between the tips of the crossed fingers. This experiment will produce the impression of there being two marbles. 122. Shut both eyes, and let a friend run the tips of the fingers first lightly over a hard, plane surface, then pressing hard, and then lightly again, and the surface will seem to be hollowed out. These two experiments show that we are easily misled, even by the sense of touch. It is mainly matter 6t habit and education. 123. Put a drop of vinegar on a friend's tongue, or your own. Notice how the papillae of the tongue start up. 124. Rub different parts of the tongue with the pointed end of a piece of salt or gum-aloes, showing that the back of the tongue is most sensitive to salt and bitter substances. 125. Repeat the same with some sweet or sour substances, to show that the edges of the tongue are the most sensitive to these things. 126. Apply the points of a pair of compasses to various places on the surface of the body, to show the most sensitive spots. ^ 127. We often fail to distinguish between the sense of PRACTICAL EXPERIMENTS 321 taste and that of smell. Chew some pure, roasted coffee, and it seems to have a distinct taste. Pinch the nose hard, and there is little taste. Coffee has a powerful odor, but only a feeble taste. The same is true of garlic, onions, and various spices. 128. Light helps the sense of taste. Shut the eyes, and palatable foods taste insipid. Pinch the nose, close the eyes, and see how palatable a teaspoonful of cod-liver oil becomes. 129. Gently turn the inner part of the lower eyelid down- KiG. 96. — Blackboard Sketch. Showing how the Image of an Object is brought to a Focus on the Retina. wards. Look in a mirror; and the small " lachrymal point," or opening into the nasal duct, may be seen in your own eye. 130. Close the eyelids, and press firmly on to the eyeball with two fingers. Note how firm and dense it is to what one might imagine. 131. The Retina is easily tired. — With a hand-mirror reflect the sunlight on the white wall, and keep it fixed. Look steadily at it for a full minute, and then let it suddenly be removed. Its " complementary " color — a dark spot — will appear. Pin a round piece of bright red paper (large as a dinner-' 322 YOUNG FOLKS PHYSIOLOGY plate) to a white wall by a single pin. Fasten a long piece of thread to it, so it can be pulled down in a second. Gaze steadily at the red paper. Have it removed while looking at it intently, and a greenish spot takes its place. 132. To illustrate the Action of the Crystalline Lens. — Hold a burning-glass in front of an open window in such a way that the image of some object outside will be brought to a focus upon a piece of paper. This miniature image will be upside down. 133. The walls of the eyeball of a white rabbit are quite transparent. Hold a lighted candle before the cornea. An image of the candle will be seen reflected on the retina. 134. " Remove the front convex lens from a pair of opera- glasses, or procure a convex lens with a gradual curve. Hold it opposite a window, and place a piece of white paper behind it to act as a screen. A small reversed picture of the window-frame will appear on the paper. " If the paper be moved to a certain distance, varying with each lens, the picture will become clear and distinct, yet with color-rings about the edges. At that distance from the lens .the paper is said to be in focus. If the paper be moved nearer to, or farther from, the lens, the picture becomes blurred, and the paper is said to be out of focus. 135. " Visit a photographer's studio. Request him to ■point out and narrie the uses of the essential parts of the camera, — the blackened box, the ground-glass screen, the lens, the diaphragm, and the apparatus for adjusting the lens and the screen to the object. Watch him place the camera and then work the ground-glass screen into the proper focus. When all is ready, put your head under the curtain of the camera and study the reversed image depicted on the glass." — Cutter's Physiology. 136. To vibrate the drum-membrane and the little ear- PRACTICAL EXPERIMENTS 323 bones, shut the mouth, and pinch the nose tightly. Try to force air through the nose. The air dilates the eustachian tube, and air is forced into the ear-drum. The distinct crackle, or clicking sound, is due to the movement of the ear-bones and membranes. 137. The Retina is not sensitive where the Optic Nerve enters the Eyeball. — This is called the "blind spot." Put two ink-bottles about two feet apart, on a table covered over with white paper. Close the left eye, and fix the right stead- ily on the left-hand ink-stand, gradually varying the distance of the eye to the ink-bottle. At a certain distance the right- hand bottle will disappear ; but nearer or farther than that, it will be plainly seen. 138. Show the same thing in this way : make two black spots, with pen and ink, as large as two peas, upon a white Fig. 97. — Diagram to show the Existence of the Blind Spot. card, about three inches apart, varying the distance as be- fore. At a distance of about six inches the " blind spot " will be noticed. 139. Impressions made upon the Retina do not disappear at once. — Look steadily at a bright light for a moment or two, and then turn away suddenly, or shut the eyes. A gleam of light will be seen for a second or two. 140. Take a round piece of white card-board the size of a saucer, and paint it in alternate rings of red and yellow, — two primary colors. Put it on the sewing-machine wheel, or glue it to a grindstone, and rotate it rapidly. The eye perceives neither color, but orange, — the secondary color. 141. To note the shadows cast upon the retina by opaque 324 YOUNG FOLKS PHYSIOLOGY matters in the vitreous humor, popularly known as floating specks, or gossamer threads, look through a small pin-hole in a card at a bright light covered by a ground-glass shade. 142. Test the eyes of the pupils by a set of Snellen's test- types. The following test-line should be easily read at ten feet. Some pupils may be able to read it at a distance of eleven or more feet. VZBDFHKOS 143. To dissect an Eye. — The eyes of a codfish, a sheep, or a pig are easily obtained. Put them in the snow over night during winter, or freeze them with salt and ice during warm weather. They are easier to dissect when frozen. Examine one specimen from the outside, however, before freezing dulls its bright colors. Saw out a square piece of the skull that holds the eye, and see just how it is held in place naturally, how the optic nerve enters the orbit, etc. Dissect with great care the frozen eye. The fat should be dissected off, together with the muscles, and the eye cut in half from above downward. This will be most easily accomplished by holding the eye between the forefinger and thumb of the left hand, upon a slice of turnip or potato, and then cutting it between finger and thumb with a sharp razor. The transparency of the cornea, lens, vitreous humor, and also of the retina should be noticed, so as to compare them with the same parts when hardened. In the posterior portion may be seen, through the trans- parent vitreous humor, the entrance of the optic nerve, and the blood-vessels which radiate from this point over the delicate, transparent retina, the latter spreading like a film over the whole of the interior of this half of the eye. PRACTICAL EXPERIMENTS 325 Remove the vitreous humor and the retina, so that the brightly colored choroid coat may be seen. Within the front half of the eye will be seen a portion of the vitreous humor and the perfectly transparent lens. The aqueous humor is best shown by taking an entire fresh eye, and cutting through the cornea, when this fluid will be seen to spurt out. Both transverse and longitudinal sections should be exam- ined. The latter are best made by placing the eye upon a piece of cork, with the cornea downwards, and then, pass- ing the razor through the middle of the optic nerve, cut the eye in half. When the razor is felt to be in contact with the hardened lens, cease to draw it, and finish the section by simply pressing it through, otherwise the lens will be drawn out of its place. 144. Get a sheep's kidney at the market. Study care- fully its shape, size, etc., as a wh6le. Freeze it, if necessary, and then cut it in two lengthwise. Notice the difference between the inner and the outer portions. This is something like the difference in texture between the pith and the hard rind of some fiower-stems, such as the sunflower. The outer part is called the cortical part, which means the " bark ; " and the inner is called the medullary, or " marrow." EXPERIMENTS ON THE THROAT AND VOICE [Chapter XIV. Page 280.] Experiment 145. To show the Anatomy of the Throat. — Study the general construction of the throat by the help of a hand-mirror. Repeat the same on the throat of some friend. 326 YOUNG folks' PHYSIOLOGY 146. To illustrate the Passage of Air through the Glottis. — Take two strips of india rubber, and stretch them over the open end of a boy's "bean-blower," or any kind of 'a tube. Tie them tightly with thread, so that a chink will be left between them. Force the air through such a tube with a bellows, oV even by blowing hard, and a sound will result if the strips are not too far apart. The sound will vary in character, just as the bands are made tight or loose. 147. " A very good illustration of the action of the vocal band in the production of the voice may be given by means of a piece of bamboo or any hollow wooden tube, and a strip of rubber, about an inch or an inch and a half wide, cut from pure sheet rubber such as is used by dentists for rubber dams. " One end of the tube is to be cut sloping in two directions, and the strip of sheet rubber is then to be wrapped round the tube, so as to leave a narrow slit terminating at the upper corners of the tube. " By blowing into the other end of the tube the edges of the rubber bands will be set in vibration, and by touching the vibrating membrane at different points so as to check its movements it may be shown that the pitch of the note emitted depends upon the length and breadth of the vibrat- ing portion of the vocal bands." — Dr. H. P. Bovi'DiTCH. 148. To show the Construction of the Vocal Organs. — Get a butcher to furnish two windpipes from a sheep or a calf. They differ somewhat from the vocal organs of the human body, but they will enable us to recognize the differ- ent parts which have been described, and thus to get a good idea of the gross anatomy. One specimen should be cut open lengthwise in the middle line in front, and the other cut in the sime way from behind. PRACTICAL EXPERIMENTS 32/ EXPERIMENTS ON MATTERS OF EVERY-DAY HEALTH [Chapter XV. Page 249.J Experiment 149. Imagine a pupil with his fingers or ears frost-bitten. Show how friction should be applied. 150. Poultices. — Bring a small lot of the necessary material into the schoolroom, to show exactly how a mustard paste, a flaxseed poultice, or any other simple poultice, is made. A small poultice four inches square is large enough for the experiment. Let one or more pupils use the same material, and make a number of poultices. 151. Fainting. — Select several places about the school- room, and show exactly how a person should be placed, sup- posing he has fainted in a crowded room. Go through every detail of treatment in your mind. 152. Apparent Drowning. — Show exactly how artificial respiration is done. Let a boy lie on a settee, and illustrate the process in every detail. It would be an excellent idea for a teacher to meet his boys at their bathing-place, and show them in still more detail. Let two boys go through the process on a playmate under the eye of the teacher, and then others might follow their example. 153. To carry an Injured Person. — Take some one of the small boys, and show how he could be carried home or else- where in case of injury. 154. Bums. — Have a small quantity of soda, sweet-oil, and lime-water in the schoolroom. Imagine a pupil has 328 YOUNG folks' physiology burned his arm or hand. Show exactly what is to be done, and how. 155. Foreign. Bodies. — A thoughtful teacher can make several experiments to illustrate the text. 156. Experiments on the Matter of treating Cuts and Bruises, ~and of stopping Bleeding. — Let red-pencil marks made on the face, arms, fingers, etc., stand for cuts. Apply suitable strips of plaster in a proper way for a great variety of imaginary cuts. After putting on the plaster, practise on bandaging the parts with strips of cotton cloth rolled for the purpose. Practise on using the handkerchief for a variety of bandages. 157. To stop Bleeding from the Arteries. — Locate the principal arteries on your own person and that of a friend. Let red-crayon marks stand for the course of the arteries. Study this part of your anatomy thoroughly. Now with strings, cords, shoestrings, handkerchiefs, elastics, strips of clothing, practise tying them so as to press deeply and firmly in the proper place. Let each one in the class practise at the same time on the same artery. Criticise and improve each other's work. 158. Poisons and their Antidotes. — Small samples of the more common and important poisons should be shown. Note carefully the appearance of each one. With each sample of poison, arrange its most common antidote. Explain exactly how it should be given. 159. Disi7ifectanis.- — -Exhibit samples of the common dis- infectants, and show how they should be used. Most school- premises furnish ample opportunities to make a series of practical experiments on ventilation and disinfection. REVIEW ANALYSIS ALCOHOLIC DRINKS, TOBACCO, AND OTHER NARCOTICS [The figures in full-face type, in the parentheses, refer to the numbers of the section in the preceding chapters of this book.] /. The Bones. (Chap. ii. p. 13.) 2. The Muscles. (Chap. iii. p. 42.) 3. Physical Exer- cise. (Chap. iv. p. 56.) 4. Food and D/-ink. (Chap. V. p. 70.) 5. Origin and Na- ture of Fer- mented Drinks. (Chap. vi.p. 81.) 6. Digestion. (Chap. vii. p. 92.) Effect of Alcohol and Tobacco on the Bones (35). 1. Effect of Alcohol on the Muscles (44). 2. Effect of Alcohol on Strength (45). 3. Effect of Tobacco on the Muscles (46). Effect of Alcohol and Tobacco on Physical Exercise (58). Effect of Drinking Tea and Coffee (72). 1. Change produced by Fermentation {74). 2. Ferments and what They do (75). 3. Alcohol a Poison (7ff). 4. Narcotic Poisons (76). 5. The Alcoholic Appetite (77). 6. The Evils of Cider-drinking (78). 7. Wine, and why it should be avoided (73). 8. Beer: Its Origin. Relation to Drunkenness (80). 9. Distilled Liquors (81). 10. The Cost of the Alcohol Vice. (Note, p. 89. ) 1. Effect of Alcohol on the Stomach Diges- tion (99). 2. Effect of Alcohol on the Liver (100). 3. Effect of Tobacco on Digestion (101). 329 330 REVIEW ANALYSIS 7. The Blood and its Circulation. (Chap. viii. p. 122.) 8. Breathing. (Chap. ix. p. 142.) 9. How the Body is ( covered. J. (Chap. X. p. 161.) L 10. The Nervous System. (Chap. xi. p. 177.) //. The Special Senses. (Chap. xii. p. 210.) 12. Excretion. (Chap. xiii. p. 235.) 13. Throat and Voice. (Chap. xiv. p. 243.) 14. Simple Matters of E very-day Health. (Chap. XV. p. 249.) 1. How Alcohol gets into the Blood (117). 2. Effect of Alcohol on the Circulation ( / 16). 3. Effect of Alcohol upon the Heart (119). 4. Effect of Tobacco onthe Heart (120). 1. Effect of Alcohol and Tobacco upon the Lungs (/52). 2. Alcohol and the Bodily Heat ( 133). 3. Alcohol in Hardship. (Note, p. 160). 1. Effect of Alcohol and Tobacco upon the Skin (145). 1. Narcotics (162). 2. General Effect of Alcohol on the Nervous System ( 163). 3. Effect of Alcohol on the Brain Tissue ( 164). 4. Final Result of Alcoholic Poisoning ( ; 85). 5. Inherited Craving for Alcohol (166). 6. Tobacco and its Use (167). 7. Evil Effect of Tobacco. (Note, p. 203.) 8. Effect of Tobacco upon Young People ( 168). 9. Tobacco from a Moral Point of View ( 169). 10. Opium (170). 11. Practical Points about Opium (171). 12. Chloral and other Poisons (172). Effect of Alcohol and Tobacco on the Special Senses ( 196). Effect of Alcohol on the Kidneys (202). Effect of Alcohol and Tobacco on the Throat and Voice (207). Pernicious Use of Alcoholic Liquors in Accidents and Emergencies (225). TEST QUESTIONS FOR REVIEW INTRODUCTORY [Chapter I. Page i.] 1. How may the child get some idea that his body moves, and is warm ? 2. What marked difference is there between all animals and all vegetables? 3. How would you compare the body to a locomo- tive ? 4. Can you tell where the comparison fails ? 5. Explain, in a general way, how we are able to cross a room, pick a flower, and do many similar acts. 6. What does the child experience when he touches a hot stove, or pricks his finger ? What good does pain do ? 7. Why do we wonder at the marvellous actions of our bodies ? 8. What is meant by anatomy ? physiology ? hy- giene ? Illustrate. 9. What is an organ ? a system .'' an apparatus .■■ 10. What is meant by the function of an organ .•• Illustrate. 1 1. What is a vital organ .' 12. What is a tissue ? 331 332 YOUNG FOLKS PHYSIOLOGY 13. Mention the principal tissues of the body. 14. Of what is the minute structure of the body made up ? 1 5. Tell what you know about cells. 16. What chemical elements are found in the body ? 17. What can you say about the general build of the body ? 18. Mention the general topics which will be dis- cussed in this book. THE BONY FRAMEWORK [Chapter II. Page 13.] 1. What do you mean by .the skeleton .'' What are its uses ? 2. How many bones are there in the human body .■• 3. Describe the composition of bone. 4. What experiments show the composition of bone ? 5. Explain the general structure of bone. Illustrate. 6. Explain and give examples of the different kinds of bones. 7. Describe the minute structure of bone. 8. What is the periosteum .' and what is its use ? 9. What can you say of the power of bone to resist decay .■' 10. Name the principal divisions of the human skel- eton. 11. Into what parts is the head divided.' TEST QUESTIONS FOR REVIEW 333 12. What is the cranium ? Mention each bone by name. 13. Give an account of the bones of the cranium. 14. What is the face .' Name each bone. 15. Describe the bones of the face. 16. How are the bones of the head joined together.' 17. What are sutures.' Explain fully their use. 18. What are the fontanelles ? 19. What is the trunk .•■ its two cavities.' 20. What is the abdomen .' and what does it contain .' 21. Describe the diaphragm. 22. Of what parts does the trunk consist .' Mention each bone. 23. Describe in full the spine. Its uses. 24. What are the ribs.' what are their uses .' 25. How are the skull and the spine joined together ? 26. How are the hips made up .' 2y. Describe the hyoid bone. 28. Describe the upper limbs. Mention the bones • of each part. 29. Describe the three bones of the upper arm. 30. Describe the two bones of the fore-arm. 31. Describe the wrist, the palm, and the fingers. 32. Describe the lower limbs. Name each bone in the three parts. 33. Describe the thigh, the lower leg, the foot. 34. What is the knee-cap .' the tendon of Achilles .' 35. Give some points of comparison between the hand and the foot. 36. Explain the use of bones. 37. How do bones grow .' How are they repaired .' 334 YOUNG FOLKS PHYSIOLOGY 38. What is a joint? Describe in full. 39. Mention the different kinds of joints. Illustrate. 40. What are the ligaments } Describe them. What are their uses ? Name some important liga- ments. 41. Give some hints about the health of bones. 42. What is the effect of alcohol upon the bones } 43. How does tobacco injure the bones.' 44. Give from memory the " review analysis " of the skeleton. THE MUSCLES [Chapter III. Page 42.J 1. How do we move } Explain in full. 2. What is muscle ? Describe its structure. 3. Explain and illustrate contraction. 4. Describe the two general kinds of muscles. 5. How are muscles arranged to do their work ? Illustrate. 6. What are tendons .' Where are they found } What are their uses ? 7. Explain how muscles act as levers of the three different classes. 8. Give examples of each class. 9. What is the number of muscles .' ID. How are they adapted to different uses .' 1 1. Mention and describe some of the important mus- cles of the body. 12. How does alcohol affect the control of the mus- cles ? TEST QUESTIONS FOR REVIEW 335 13. How does alcohol affect the speech? 14. Why does alcohol sometimes give rise to the idea that it adds to or renews strength ? 15. How can this idea be shown to be false ? 16. Explain what is known as fatty decay. 17. What is the effect of fatty decay on the heart, liver, and other organs ? 18. How do the muscles of the beer-drinker differ from those of the total abstainer ? 19. How does tobacco affect the muscles ? How is this shown ? PHYSICAL EXERCISE [Chapter IV. Page 56.] 1. What is meant by physical exercise ? 2. Why do we need it .'' 3. What are some of the ill effects of too little exer- cise .'' 4. In a general way, describe the effect of exercise on the various organs. 5. How much exercise should we take .' 6. Mention some points of contrast between health and strength. 7. What is the best time for exercise ? 8. Give in detail the different kinds of exercise. 9. Show the beneficial effect of physical exercises in schools. 10. Why is a certain amount of physical training an important matter in our school system .' 336 YOUNG folks' physiology 11. Give some points about the importance of physi- cal development. 12. In a general way, tell what you can about the various systems of gymnastics. 13. Give in some detail the essential features of the Swedish system. 14. What are the important features of the German system ? 15. What benefits may be derived from a modern gymnasium .■" 16. What system of gymnastics is needed for the schools in this country ? 17. What features are essential for any system to be popular and beneficial in our schools ? FOOD AND DRINK [Chapter V. Page 70.] 1. To illustrate work, waste, and repair, how may you compare the human body to a steam-en- gine ? Explain in detail. 2. How does the comparison fail in some things .'' 3. Why do we need food } 4. What are the three great classes of foods .' 5. Describe and illustrate the nitrogenous foods (albumens). Give examples. 6. What are the starches and sugars ? Give ex- amples. 7. Describe and illustrate the oils and fats. 8. What is meant by the inorganic or mineral foods ? TEST QUESTIONS FOR REVIEW 337 9. What do you mean by " appetizers " ? Illustrate. ID. Describe the principal kinds of vegetable food. 11. Explain the importance of salt, and give many illustrations of its value. 12. What are some of the principal articles of animal food .? 13. What is the use of mineral food ? 14. What is the natural drink provided by Nature for all living things ? 15. Explain how water acts to rid the body of waste and refuse matters. 16. What is essential for water to be suitable as an article of diet ? 17. Mention some of the more common artificial drinks. 18. Tell what you can about tea, coffee, and cocoa. 19. What can you say of ice-water .' 20. In a general way explain the harmful effects of tea and coffee. ORIGIN AND NATURE OF FERMENTED DRINKS [Chapter VI. Page 8i.] 1. Of what are fruit juices composed .' 2. How long will such juices remain healthful after they have been drawn off from the fruit and left standing in ordinary air ? 3. Why does plant and animal matter decay .■" 4. What name is given to the process of decay that goes on in fruit juices that are pressed out and left exposed to the air ? 338 YOUNG folks' physiology 5. What does fermentation in its widest sense include ? 6. What is the law of fermentation ? 7. What causes the various processes of decompo- sition ? 8. What would be the condition of the earth if it were not for these minute living forms ? 9. To what class or plant family do the disease germs belong? 10. Name other plant cells belonging to this family, and tell what they do. IL What is the work of the moulds? To what class do they belong ? 12. To what class do the ferments belong ? What is their work ? 13. When do the ferments enter the fruit juice ? 14. Show what the ferments do in the fruit juice. 15. What is the nature of the fruit juice before fer- mentation ? What is its nature after fermen- tation ? Of what law is this an illustation ? 16. What further changes take place in wine or cider when left standing in warm air? 17. What would become of the vinegar if left to itself ? 18. What is a poison ? Show why alcohol is a poison. 19. What are narcotic poisons ? 20. What are the characteristics of a natural appetite ? 21. What is the difference between a natural appe- tite and the appetite for alcohol ? 22. Upon what does the character of a substance depend ? TEST QUESTIONS- FOR REVIEW 339 .23. What is the secret of the drunkard's craving for alcohol ? 24. What is the only safeguard against forming the alcoholic appetite and the only cure when it is formed ? 25. Why should alcoholic liquors never be used as a flavoring for food ? 26. What is cider ? What poison does it con- tain ? 27. How soon after cider comes from the press can alcohol usually be found in it ? 28. Why is cider an unsafe drink ? 29. What follows if a person drinks the same quan- tity of cider every day while it is growing hard ? 30. From what is wine made ? 31. Why are we in no danger of being injured by . alcohol if we take our fruit juices fresh from . the fruit ? 32. Why are some wines called " light wines " ? Why are these unsafe drinks ? 33. What disproves the theory that " light wines " will prevent the use of stronger drinks ? 34. From what is beer made ? 35. Show how alcohol is formed in beer. 36. What effect does beer appear to have upon the moral nature ? 37. Describe the beer-drinker's appearance and dan- gers. 38. What is the testimony of life-insurance compa- nies in regard to beer-drinking > 340 YOUNG FOLKS' PHYSIOLOGY 39. What other drinks are sometimes made by allow- ing yeast to act on the sugar of a sweet liquid ? Why should no such liquors be made and used as beverages ? 40. Show how distilled liquors are obtained. 41. How is the craving for the stronger or distilled liquors acquired? DIGESTION [Chapter VII. Page 92.J 1. Describe the digestive tube as a whole. 2. What is meant by digestion ? Name the various steps. 3. What is meant by chewing .-' 4. Describe the structure of a tooth. Mention the number and situation of the teeth, giving the names of each kind. 5. What can you tell of the salivary glands and the saliva .'' Explain what is meant by secretion and excretion. 6. Explain in some detail how we swallow food. 7. What prevents food from getting up into the nose, and down into the windpipe ? Explain in full. 8. Describe the stomach. 9. What is the gastric juice.'' How is it secreted .-• Describe its action. 10. What are the intestines .'' TEST QUESTIONS FOR REVIEW 34I 11. Describe the liver. The bile. The pancreatic juice. The intestinal juice. The action of each. 12. In a general way, describe the process of absorp- tion. 13. Describe the process of absorption by means of the lacteals and the lymphatics. 14. What is the thoracic duct and its office .-' 15. Lymphatic glands and the work they do } 16. Explain absorption by the blood-vessels. 17. Describe the spleen, the thymus and thyroid glands. 18. Describe the large intestines. 19. How much should we eat .' Various circumstances affecting this question. 20. What guides have we as to what we should eat t 21. Describe in full when we should eat. 22. How should we eat } Explain in detail. 23. Give some practical points about the care of the bowels. 24. Why is a knowledge of proper cooking so neces- sary .'' 25. Care of the teeth. Its great importance. Give details. 26. Describe the indigestion due to alcohol. 27. What is the effect of alcohol on the stomach } 28. What is its action on the liver .'' 29. What is the effect of tobacco on digestion .' 342 YOUNG folks' PHYSIOLOGY THE BLOOD AND ITS CIRCULATION [Chapter VIJI. Page 122.J 1. Of what use is the blood ? 2. How is the blood made up ? 3. What is the total quantity in the body ? 4. How does it look ? its color ? 5. How does blood look under the microscope ? 6. Describe the red blood corpuscles. 7. Describe the white blood corpuscles. 8. What is meant by the coagulation of blood .' 9. How may you compare the flow of blood circu- lation to a' force-pump .'' to the water-system of a great city ? 10. Describe the heart. 11. Explain the terms auricle, ventricle, valve. 12. What can you tell of the work done by the heart .■• 13. Describe the action of the valves of the heart. 14. Name the blood-vessels connected with the heart. Tell with which part of the heart each is connected. 15. Describe in a general way the differences be- tween the veins and arteries. 16. Describe the aorta. Some of its great branches. 1 7. What are the veins .■• Describe their valves. 18. To what may the venous system be compared .' 19. What are the capillaries .-' their use .■• 20. Give a general description of the circulation of the blood through the body. TEST QUESTIONS FOR REVIEW 343 21. How much time does it take ? 22. Describe the sounds of the heart. 23. What is meant by palpitation of the heart ? 24. What is the pulse ? What may it tell us ? 25. What is the general effect of alcohol on the circulation .■" 26. How does alcohol get into the blood .'' 27. How may alcohol affect the corpuscles of the blood ? 28. In what other way may the blood be injured by alcohol .■■ 29. What is the effect of alcohol upon the heart ? 30. What is the harm in thus increasing the fre- quency of the heart's beats .' 31. What is the real cause of the so-called "stimu- lating " effect of alcohol on the heart ? 32. What is the effect of tobacco on the heart ? BREATHING [Chapter IX. Page 142.] 1. What is the object of breathing ? 2. Wky do we breathe .'' 3. Describe the air-passages. 4. How are they lined and protected .'' 5. Give a short description of the lungs. 6. What is the pleura ? 7. Describe the mechanical movements of breath- ing. 8. How do we breathe ? 344 YOUNG FOLKS PHYSIOLOGY 9. Describe the changes in the air from breathing. 10. How may we compare the lungs to a market- place ? 1 1. What is carbonic acid ? where found ? its poison- ous effects ? 1 2. What impurities may exist in the air ? 1 3. What are the chief dangers from impure air ? 14. What are the practical effects of impure air ? 15. Why and how should we ventilate ? Give some practical plans. 16. The ventilation of schoolrooms, — why and how is it done .' 17. What is the proper temperature of our living- rooms ? Explain in some detail. 18. Animal heat. How is the body kept warm ? 19. Explain and illustrate this slow combustion, or oxidation. 20. What is the effect of alcohol upon the lungs .' 21. Explain in detail the action of alcohol upon the' bodily heat. 22. Show how alcohol lessens the power to endure hardship and extremes of heat or cold. Give illustrations. HOW OUR BODIES ARE COVERED [Chapter X. Page 161. J 1. What is the skin ? and what is its use? 2. Describe its structure in a general way. 3. Give in detail a description of the cuticle, or scarf-skin. TEST QUESTIONS FOR REVIEW 345 4. Where is the coloring-matter of the skin situ- ated ? 5. Describe the cutis, or true skin. 6. Show how the skin may absorb poison. 7. Describe the hair ; its structure ; muscles; num- ber of hairs. 8. Describe the nails. 9. What care would you take of them .' 10. What are the oil-glands ? 11. Describe the sweat-glands. 12. What is the use of the sweat ? 13. Give some reasons why we should take care of the skin. 14. Baths. Why, when, and how to take them. 15. Why do we need clothing ? 16. Give some hints about the use of clothing. 1 7. What is the effect of alcohol upon the skin .' THE NERVOUS SYSTEM [Chapter XL Page 177.] 1. Show how the various parts of the body act in harmony. 2. Draw a parallel between the nervous system and the telegraph. 3. Give familiar illustrations to show the general action of the nervous system. 4. What are the two distinct systems? 5. What is nerve-tissue.'' 346 YOUNG folks' physiology 6. What are the nerves ? 7. Give a short description of the brain. 8. What is the usual size of a human brain ? 9. Describe fully the cerebrum, or brain proper. 10. What are the functions of the cerebrum ? 11. Describe the three coverings of the brain. 12. Locate and describe the cerebellum. What is its function ? 13. Describe the medulla oblongata. What are its functions .' 14. What do you understand by the cranial nerves ? 15. How are they arranged.' What is the pneumo- gastric nerve ? 16. Describe briefly the spinal cord. What are its functions .' 17. Explain fully what you understand by reflex action. 18. Give several familiar examples to illustrate reflex action. 19. Describe the importance of reflex action. 20. What are the spinal nerves .■' Explain motor and sensory nerves. 21. Describe the sympathetic system of nerves. 22. What are the functions of the sympathetic nerves ? 23. What tends to keep the nervous system in good order ? 24. What about the abuse of the nervous sys- tem ? 25. Why is sleep necessary.' 26. Give some practical hints about sleep. TEST QUESTIONS FOR REVIEW 347 27. What is one of the most fruitful sources of injury to the nervous system ? 28. What are narcotics ? 29. Why is the person who takes alcoholic drinks once liable to take them again ? 30. How does alcohol affect the substance of the nerves ? 31. What causes the face to flush when a small quan- tity of alcohol has been taken ? 32. What is the first effect of alcohol on the brain ? 33. What shows that this unusual activity of the brain is an unhealthful excitement ? 34. What are some of the common liquors that have this power to weaken the judgment and blunt the moral sense ? 35. What part of the brain is first brought under the poisonous influence of alcohol ? 36. How is this shown ? 37. What part of the brain is next affected when larger quantities of alcohol are taken ? 38. In what way is this shown ? 39. Describe the last stage of alcohol poisoning. 40. What injurious effects follow the continual use of alcohol ? 41. What terrible disease often results? 42. What is the relation of drink to insanity ? 43. What are some of the other evil consequences brought upon the nerves and nervous system by the use of alcohol ? 44. What evil inheritance may result from alcoholic habits ? 348 YOUNG folks' physiology 45. What are some of the ill effects of tobacco upon the nerves ? 46. How does it affect the mind ? 47. Show why cigarettes are especially injurious. 48. How is the effect of tobacco on the moral nature frequently shown ? 49. Why is it no act of kindness to offer a person a cigar or cigarette .'' 50. Opium. What is it > for what used ? what about the opium habit .■" 51. Give some practical hints about opium. 52. What about chloral .? other narcotics ? 53. What new drugs are hurtful to health.' the special senses [Chapter XH. Page 210.] 1. What is meant by the term sensation ? Illustrate. 2. What is the real centre of sensation ? Illustrate. 3. What are the three organisms necessary to receive sensation .'' 4. Give several examples to show this. 5. Name and define the five special senses. 6. What is meant by the " muscular sense " .' 7. Tell how the skin acts as an organ of touch. 8. What parts of the body are most sensitive to touch .'' 9. Does the sense of touch become more sensitive by practice .■• TEST QUESTIONS FOR REVIEW 349 10. Describe the tongue as the principal organ of taste. 11. Where is the sense of smell located? 12. How are we able to detect an odor.' 13. What are the uses of the sense of smell ? 14. What is the sense of hearing ? 15. Explain in a general way how sound travels through the air. 16. Describe the outer ear. 17. What is the middle ear .' the inner ear ? 18. Explain just how we are able to hear. 19. Give some practical hints about the care of the ear. 20. What is meant by the sense of sight ? 2 1 . What is the eye .'' where located 1 22. Describe the coats of the eye. 23. Explain in some detail the inner parts of the eye. 24. Describe in full the mechanism of vision. 25. What is meant by the term " focus " .' Illustrate. 26. How are images brought to a focus on the retina .-' 27. Show how the eye is moved by muscles. 28. What use are the eyelids .'' eyebrows .' 29. Tell what you know of the tears, tear-glands, and ducts. 30. What is meant by color-blindness ? 31. What is meant by near-sight and far-sight .' 32. Give some practical hints about the care of the eyes. 33. What is the general effect of alcohol and tobacco on the special senses. 34. How do alcohol and tobacco affect the hearing ? 350 YOUNG FOLKS PHYSIOLOGY 35. What effect do they have on the eyes and eye- sight ? 36. Show how cigarettes are especially hurtful to the throat and the eyes. EXCRETION [Chapter XIII. Page 235.] 1. Why is it necessary to get rid of the waste mat- ters of the body .-' 2. How would you compare the body to an engine in this matter of getting rid of waste material ? 3. Describe the principal waste matters of the body. 4. What are the three great organs of excretion .' 5. How are their functions related one to the other .'' 6. Describe the kidneys. 7. What are their functions ? 8. What is the general effect of alcohol upon the kidneys } 9. What effect does alcohol have on the tissue-waste .■' 10. How does alcoholic liquor change the structure of the kidneys .'' 11. What disease of the kidneys is apt to be induced by alcoholic indulgence ? THE THROAT AND VOICE [Chapter XIV. Page 243.] 1. What is the throat ? 2. How is it exposed to disease .■' 3. In what way can you get an idea of the throat ? TEST QUESTIONS FOR REVIEW 35 1 4. What parts of the throat can you see by looking into a friend's mouth ? Explain in full. 5. Describe the pharynx. 6. Give some hints about the care of the throat. 7. Describe the organ of speech. 8. What are the vocal cords ? Describe them. 9. What is meant by the voice .-• 10. Upon what does the compass of the voice de- pend .'' 11. What regulates the quality of the voice ? 12. What is the general effect of alcohol on the voice ? on the vocal cords.' on the delicate lining of the throat .'' 13. How does tobacco affect the vocal cords .' 14. How is sore throat frequently caused ? 15. How do cigarettes affect the throat-passages and " the voice .' SIMPLE MATTERS OF EVERY-DAY HEALTH [Chapter XV. Page 249.J 1. What is meant by "simple matters of every-day health " ? 2. Mention some things of the kind likely to happen. 3. What real good may one do under such cir- cumstances ? 4. Describe in detail the process of making poul- tices. 5. When and how would you use them .-' 6. What would you do for fainting ? 352 YOUNG FOLKS' PHYSIOLOGY 7. Convulsions, and what to do for them. 8. What is meant by asphyxia ? What is the treat- ment ? 9. Describe in detail what is to be done in apparent drowning. ID. What is sunstroke or heatstroke ? What would you do .'' 1 1. How would you know that a bone was broken .■" 12. How would you manage with a broken bone .' 13. How would you carry an injured person .'' 14. What is the treatment for burns and scalds ? 15. What is frost-bite ? What would you do for it .' 16. What would you do for a foreign body in the throat .■" in the nose .'' in the ear .' in the eye .' 17. How would you know the difference between bleeding from an artery and bleeding from a vein .■■ 18. On what general principles would you act to stop bleeding .' 19. What would you do to stop bleeding from an artery .-' from a vein ? 20. Can you tell the difference between blood com- ing from the lungs and that from the stomach ? If so, how ? 21. What would you do for nose-bleed } bruises .'' cut and torn wounds .' 22. What will you say about the pernicious use of alcoholic liquors in accidents and emergen- cies .'' 23. Describe in detail how you would make a sick- room look neat and clean. TEST QUESTIONS FOR REVIEW 353 24. How would you make a sick person more com- fortable ? 25. Are persons likely to swallow poisons acciden- tally ? If so, when ? Mention some poisons often accidentally swallowed. 26. What general treatment would you give for all poisons ? 27. Describe the more common acid poisons, and give their antidotes. 28. Mention the alkaline poisons. Their antidotes. 29. Mention some metallic poisons, and give an- tidotes. 30. Mention some narcotic poisons. Their antidotes. 31. What other things may act as poisons ? 32. How may the air be poisoned .■' 33. What is meant by disinfection .-' 34. In what general way would you use disinfectants .' 35. Mention the three most common disinfectants. 36. Describe in detail how disinfectants should be used. NOTES ADDITIONAL TESTIMONY CONCERNING THE NATURE AND EFFECTS OF ALCOHOLIC DRINKS AND OTHER NARCOTICS. Note i. — " Besides the danger connected with the use of alcoholic drinks, which is common to them with other nar- cotic poisons, alcohol retards the growth of young cells and prevents their proper development. Now, the bodies of all animals are made up largely of cells, as heretofore shown, and' the cells being the living part of the animal, it is espe- cially important that they should not be injured or badly nourished while they are growing. So that alcohol in all its forms is particularly injurious to young persons, as it retards their growth- and stunts both body and mind. This is the theory of Dr. Lionel S. Beale, a celebrated microscopist and thinker, and is quite generally accepted." — Dr. Roger S. Tracy. " On entering college (Yale), the class of '91 had a list of thirty-eight tobacco-users, or about eighteen per cent of the two hundred and five men. At the beginning of junior year this percentage had been slightly increased, although eigh- teen of the men who had been recorded as tobacco-users had left college for one reason or another. At the end of senior year the record stands as follows : — " There are seventy-seven men who never used tobacco. " There are twenty-two men who have used it slightly at rare intervals, of whom six have begun the practice in the last term of senior year. 355 356 YOUNG folks' physiology There are eighteen who have been hard smokers at differ- ent periods of the course. " There are seventy men who have used it regularly. . . . "In weight the non-users increased 10.4^ more than the regular users, and 6.6 fa more than the occasional users. In the growth of height the non-users increased twenty-four per cent more than the regular users, and fourteen per cent more than the occasional users." — jPro/. J. W. Seaver, M.D., of Yale, in the University Magazine, June, 1891. " Smoking prevents a healthy nutrition of the several structures of the body. Hence comes, especially in young persons, an arrest of the growth of the body, low stature, an unhealthy supply of blood, and weak bodily powers." — Dr. J. Copland, F.R.S., of England. "When the Europeans first visited New Zealand, they found the natives the most finely developed and powerful men among the islands of- the Pacific. Since the introduc- tion of tobacco, for which these men developed a passionate liking, they have, from this cause alone, become decimated in numbers, and so reduced in stature and physical well- being as to be an altogether inferior type of men." — New York Medical Journal. Note 2. — " Dr. Parkes made three soldiers march twenty miles a day for six days, loaded with gun, knapsack, pouch, etc. They had the same food every day ; but on two days they drank brandy and water, on two coffee, and on the other two weak beef-tea. All three found that, though the spirit revived them for a little while, they were more tired at the end of the journey on the two days when they took brandy than on any of the other two." — Dr. N. S. Davis. " There is no muscle about beer. This is abundantly illustrated by the thousands of beer and wine drinkers, who. NOTES 357 from twenty to twenty-five years of age, were muscular, active, capable of any reasonable endurance, with a weight of one hundred and fifty pounds, but who, after moderately retarding atomic changes, and retaining old atoms by the daily use of wine or beer, have acquired a weight of two hundred pounds or more, and have lost their muscular activ- ity and endurance to such an extent that active exercise of twenty minutes would make them puff like a heavy horse." — Dr. N. S. Davis. " It has been demonstrated on all sides, at the forge, in the workshop, in the field, on the march, in the arctic region, and in the torrid zone, in physical and in intellectual labor, that the spirit-drinker fails to cope with the temperate man." — Dr. Willard Parker. " It is now well known and acknowledged by scientific men, that less muscular labor can be performed under the influence of alcohol, in whatever quantity, than without it. In the performance of great feats of strength and endur- ance, as in the case of Weston, the famous pedestrian, alcohol has been avoided; and in the harvest-field and the work- shop, and with contestants in the ancient Roman games, the advantage has ever been with abstainers. The most conclusive tests have been in armies in severe marches, where accurate observation on a large scale has been made by intelligent medical and commanding officers. In all such tests, whether in hot or cold climates and seasons, — in Africa, India, Russia, and Canada — in our own country and everywhere, it has been shown that those soldiers who abstained from alcohol could accomplish and endure more than those who indulged in it, however moderately or freely. In emergencies, those officers who allow its use at all find that it must be given when the men have accomplished their day's work and are resting after their labor. It may then 3S8 YOUNG folks' physiology blunt the sense of fatigue and promote sleep, but, unfortu- nately, it lessens the power of work for the next day, and if its use becomes habitual, other mischief will be done." — Dr. A. B. Palmer. " Voluntary muscular power seems to be lessened, and this is most marked when a large amount of alcohol is taken at once ; the finer combined movements are less perfectly made. Whether this is by direct action on the muscular fibres, or by the influence on the nerves, is not certain. In very large doses it paralyzes either the respiratory muscles or the nerves supplying them, and death sometimes occurs from the im- pairment to respiration." — Dr. Edmimd A. Parkes, F.R.S. Note 3. — " One of the first things demanded of a young man who is going into training for a boat-race is, ' Stop smoking.' And he himself, long before his body has reached its highest point of purity and development, will become conscious of the lowering and disturbing effects of smoking one inch of a mild cigar. No smoker who has ever trained severely for a race, or a game, or a fight, needs to be told that smoking reduces the tone of his system : he knows it." — James Parian. " A man who, after election as a member of his college crew, should be found secretly drinking beer or smoking, would be hissed out of college." — Dr. H. Newell Martin. Note 4. — " All that has lived must die, all that is dead must be disintegrated, dissolved, or gasified ; the elements which are the substratum of life must enter into new cycles of life. If things were otherwise the matter of organized beings would encumber the earth, and the law of the perpe- tuity of life would be compromised by the gradual exhaustion of its materials. One grand phenomenon presides over this vast work — the phenomenon of fermentation. . . . NOTES 359 " Fermentation and putrefaction only represent the first phase of the return to the atmosphere and to the soil of all that has lived. Fermentation and putrefaction give rise to substances which are still very complex, although they repre- sent the products of decomposition of fermentable matters. When sugar ferments a large portion of it becomes gas ; but alongside of the carbonic acid gas which is formed, and which is, indeed, a partial return of the sugar to the atmos- phere, new substances, such as alcohol, succinic acid, glyce- rine, and materials of yeast, are produced. When the flesh of animals putrefies, certain products of decomposition, also very complex, are formed, with the vapor of water and other gases of putrefaction." — "Louis Pasteur: His Life and Labors." Note 5. — " It has been known since very ancient times that sweet juices of fruits, more particularly of the grape, can be made to undergo certain changes, the result of which is that the juice is no longer a sweet, innocuous liquid, but possesses intoxicating properties. During the occurrence of this change the clear fluid becomes turbid, and its surface is covered by bubbles or froth. This latter phenomenon attracting special attention, the name fermentation was given to the process. We now know that the change consists in the transformation of the sweet substance sugar into other materials, of which the most abundant are alcohol, the body possessing the intoxicating properties, and carbonic acid, the evolution of which causes the frothing. The turbidity of the liquid is caused by the presence of numerous unicellular organisms, which increase rapidly by a process of budding." — Halliburton's " Text Book of Chemical Physiology and Pathology." " Thus in the destruction of that which has lived, all 360 YOUNG folks' physiology reduces itself to the simultaneous action of these three great phenomena, — putrefaction, fermentation, and slow combus- tion. A living organism dies, animal, plant, or mineral, or the remains of the one or the other. It is exposed to the contact of the air. To the life which has quitted it, succeeds life under other forms. In the superficial part which the air can reach, the germs of the infinitely small aerobies (micro- organisms which cannot live without free oxygen) hatch and multiply themselves. The carbon, the hydrogen, and the- nitrogen of the organic matters are transformed by the oxy- gen of the air, and under the influence of the life of these aerobies, into carbonic acid, vapor of water, and ammonia gas. As long as organic matter and air are present, these combustions will continue. While these superficial combus- tions are going on, fermentation and putrefaction are doing their work in the interior of the mass by the developed germs of the anaerobies, which not only do not require oxygen for their life, but which oxygen actually kills. Little by little, at length, by this work of fermentation and slow combustion, the phenomenon is accomplished. Wheth- er in the free atmosphere or under the earth, which is always more or less impregnated with air, all animal and vegetable matters end by disappearing. To arrest these phenomena, an extremely low temperature is required. It is thus that in the ice of the Polar region antediluvian elephants have been found perfectly intact. The microscopic organisms could not live in so cold a temperature. These facts still further strengthen all the new ideas as to the important part per- formed by these infinitely small organisms, which are, in fact, the masters of the world. If we could suppress their work, which is always going on, the surface of the globe, encumbered with organic matter, would soon become unin- habitable." — '^'' Louis Pasteur : His Life and Labors." NOTES 361 Note 6. — " It is entirely safe to say that there is not an occupation or condition in human society in whicli those who use any variety of fermented or distilled liquors, even in the most ' decent and orderly manner,' do not furnish more cases of sickness and more deaths annually than are furnished by an equal number occupying the same conditions but totally abstaining from all drinks." — Dr. N. S. Davis. "Alcohol taken into the body paralyzes and weakens the nerves, hardens and contracts the animal fibre ; the capillaries, arteries, veins, lymphatics, or other canals and ducts for conveying fluids, are lessened in their diameter, and are ultimately obstructed, so that the foundation is laid for many diseases." — Dr. John Higginbottom, F.R.S. Dr. Henry Thompson, an English physician of large practice, declares that he has " no hesitation in attributing a very large proportion of the most painful and dangerous maladies to the ordinary and daily use of fermented drinks in quantities conventionally deemed moderate." '• I state unhesitatingly that from experience and observa- tion, the use of light wines and beer is positively injurious to many persons; and I am forced to believe that even if in others no pernicious effects be observed immediately, such effects will become apparent sooner or later." — Dr. T. F. Allen of New York City. " I would say that both theoretically and practically, I do not believe in even a moderate use of light wines and beer as a beverage. The harm they do will not be manifested usually during perfect health ; but in times of severe sickness I believe a person's power to resist disease is in proportion to his abstinence from all forms of liquor, even in the light forms." — Dr. B. N. Bridgeman. " In addition to the injurious effects morally, which the moderate use of alcohol produces, and all drunkenness is 362 YOUNG folks' physiology born of it, it is injurious physically also I believe, and chiefly so in the following ways : (a) alcohol acts detrimentally upon the blood corpuscles and fibrinous elements of the blood, pro- ducing a ragged or cog-wheel margin of the former, and ready coagulation of the latter, with hardening of the coats and consequent loss of elasticity of the blood-vessels, thus producing the most favorable condition for plugging of the capillaries, (b) By its action upon the mucous membrane of the alimentary canal and other portions of the body, the system is less amenable to remedies and constant repair. (c) It increases the tendency to congestion and inflammation generally, and in many cases produces a fatal result in a not necessarily fatal disease, (d) What is true in health is even more true in disease, and I believe that even more cases of pneumonia succumb through its use that might otherwise recover." — Dr. D. G. Dowkoutt. Note 7. — "I can see nothing in the action of alcohol in the human body, in any case or at any time, but that of a paralyzer ; and I see in that view the key by which we can explain all the contradictory phenomena and all the contra- dictory benefits which have been ascribed to the influence of alcohol." — Dr. James Edmunds. " Alcohol, the rectified product of the vinous fermentation (i. e., decomposition) of various saccharine fluids, and in- cluded by chemists among the narcotic poisons, exercises a metamorphosic effect on every organ of the human body." — Dr. Felix Oswald. " Alcohol, for all intents and purposes, may be regarded as a sedative or narcotic rather than a stimulant." — Dr. Samuel 14'ilks. " The whole class of alcoholic liquors may be considered as narcotics, producing very little difference in their ultimate effects on the system." — Dr. William Beaumont. NOTES 363 " The flushing of the face (produced by alcohol) is caused by the paralysis of the cervical branch of the sympathetic nerve. This symptom usually occurs some time before the conspicuous manifestation of the ordinary signs of intoxica- tion which result in paralysis of the cerebrum ; we may search in vain among the phenomena of intoxication for any genuine evidence of that heightened mental activity which is said to be followed by depressive recoil. There is no recoil, there is no stimulation. There is nothing but paralytic dis- order from the moment narcosis begins." — Prof. John Fiske, of Cambridge, Mass. " It is the diminution of nerve sensibility that renders the individual at first light, airy, and hilarious, giving the popu- lar idea of excitement or stimulation ; second, dull, hesitat- ing, or incoherent in thought or speech, and unsteady or swaggering in gait, a stage popularly recognized as incipient intoxication ; and third, brings on entire unconsciousness and muscular paralysis, constituting dead drunkenness or complete anaesthesia. These successive stages are devel- oped in direct ratio to the quantity taken." — Dr. N. S. Davis. Note 8. — " The habitual use of alcoholic liquids, by the anaesthetic effect of alcohol on the human system, tends con- stantly to create an appetite for more, and consequently moderation from the beginning very generally leads directly to excess sooner or later." — Dr. N. S. Davis. " I observed as a physiological or, perhaps, psychological fact, that the attraction of alcohol for itself is cumulative : that so long as it is present in the human body, even in small quantities, the longing for it, the sense of requirement for it, is present, and that as the amount of it insidiously increases, so does the desire." — Dr. B. W. Richardson. 364 YOUNG folks' physiology " Alcohol creates an appetite for itself that soon becomes irresistible, and every drunkard will admit that when he be- gan to drink he had no intention of becoming a drunkard." — Dr. R. Gowans. " The physician who prescribes narcotics is dogged by the ever-present danger that his patients may acquire a craving for the drugs thus ordered. ... It is a common experience that a morphia or a chloral habit owes its origin to the orders of a medical attendant, who has therefore incurred a most serious responsibility. Alcohol, as the temperance reformers have so long insisted, must be included in the list." — The Birmingham Medical Review. " In the case of moderate drinking, either of malt or spirituous liquors, there is small hope that the habitual drinker will remain a moderate one." — A. G. Bullock, Presi- dent Mutual Life Insurance Company. " The power of moral resistance is weakened with every repetition of the poison dose." — Dr. Felix Oswald. " It is the temperate use of alcohol that creates the appe- tite of the inebriate." —Z>r. William Hargreaves. " It will be admitted, I presume, by all who hear me that if there were no temperate drinking there would be none that is intemperate. Men do not begin by what is usually called immoderate indulgence, but by that which they regard as moderate. Gradually and insensibly their draughts are increased until the functions of life are permanently dis- turbed, the system becomes inflamed, and there is that morbid appetite which will hardly brook restraint, and the indulgence of which is sottish intemperance. Let it be remembered, then, that what is usually styled temperate drinking stands as the condition precedent of that which is intemperate. Discontinue one and the other becomes im- possible." — From an address by A. Potter, D.D., late Bishop of the Diocese of Pennsylvania. NOTES 365 Note 9. — " Of 623 moderate and immoderate drinkers with whom I have conversed, 337 tell me that they acquired the desire for wine and other alcoholic poisons by their use in articles of diet, and in the family and social circles, dealt out to them by their wives, and sisters, and female friends. Of this number, 161 cases (more than twenty-five per cent) were from the use of liquors in articles of diet. Of the whole number referred to, 328 fill a drunkard's grave." — A physician prominently connected with a leading life-insurance company. Note 10. — "We have been told in America, and I fully believed it, that if a people could be supplied with a cheap wine, they would not get drunk — that the natural desire for some sort of stimulant would be gratified in a way that would be not only harmless to morals, but conducive to health. I am thoroughly undeceived. The people drink their white wine here to drunkenness. ... So this question is settled in my mind. Cheap wine is not the cure of in- temperance. The people here are just as intemperate as they are in America ; and, what is more, there is no public sentiment that checks intemperance in the least. The wine is fed freely to children, and by all classes is regarded as a perfectly legitimate drink. ... I firmly believe that the wines of Switzerland are of no use except to keep out whis- key, and the advantages of the wine over the whiskey are not very obvious. It is the testimony of the best men in Switzer- land — those who have the highest good of the people at heart — that the increased growth of the grape has been steadily and correspondingly attended by the increase of drunkenness. They lament the planting of a new vineyard as we at home lament the opening of a new grog-shop. They expect no good of it to anybody. They know and 366 YOUNG folks' physiology deeply feel that the whole wine-producing enterprise is charged with degradation for their country." — Dr. J. G. Holland, in the Springfield Republican. " That wine will intoxicate, does intoxicate, that there are confirmed drunkards in Paris and throughout France, is notorious and undeniable. You can hardly open a French newspaper that does not contain some account of a robbery perpetrated upon some person stupefied by over-drinking, — a police case growing out of a quarrel over the wine-cup, or a culprit, when asked why the sentence of law should not be pronounced on him, replying, 'I was drunk when this hap- pened, and know nothing of the matter.' That journeymen are commonly less fitted for and less inclined to work on Monday than on other days of the week is as notorious here as it ever was in any other rum-drinking city." — Horace Greeley, in a letter from Paris. "In September, 1887, the French Minister of Finance organized an alcoholic commission of which M. Leon Say was made president, to investigate the subject of alcoholism. In his report, which has since been published, he deals with the hygienic aspects, and represents that alcoholism is to-day in France one of the most serious dangers of the times. Not only men, but women and children, are affected. Mental diseases hitherto unknown have become common. A pre- vious commission, appointed by the French Senate in 1886, reported that alcoholism threatened the people of France with rapid degeneration." — Dr. K. Mitchell. " I had entertained a hope that the manufacture of pure wines and their introduction into general use would crowd out the gross strong liquors and diminish intemperance. I am now fully convinced that this hope was groundless and delusive. In wine-growing districts intemperance is on the increase, extending to the youth of both sexes." — Rev. Dr. Stone of California, formerly of Park-street Church, Boston. NOTES 367 The editor of the Pacific says, " Wine has become as cheap as milk, and is as freely drunk, till many once sober men are growing habitually intoxicated. One leading man enumer- ated to us five of his acquaintances who, once noble men, are now drunkards through wine." " A few weeks ago there arrived at my house a niece of mine from the missionaries in Persia, born in that vine-grow- ing land and- familiar with the habits of the people. She repeats the testimony given by her father in 1867 at our State House, before the License Committee. This young lady speaks of the lamentable ravages of intemperance in that land at the present time, caused by using the wine made from the pure juice of the grape. They have large earthen jars, one-third sunk in the ground, and so high that a man must stand on a stool to reach the top. These are filled with grape-juice ; sheepskin is stretched over the top and plas- tered with clay. After some two months it is fermented ; but as it will turn to vinegar in a few weeks if opened, a man invites his friends, and for a week or ten days, till his jar is empty, they continue in a state of beastly intoxication. After a time a neighbor opens one of his jars, and a similar scene is enacted.'' — Rev. A. H. Plumb, D.D., in an address given in Tremont Temple, March, 1881. Note ii. — "A copious beer-drinker is all one vital part. He wears his heart on his sleeve, bare to a death-wound even from a rusty nail or the claw of a cat." — Dr. Grinrod, a prominent London physician. John S. Ford, writing from Milwaukee, Wis., to The Boston Traveller, says, " Physicians of this city who have had wide experience are of the opinion that the person who uses beer habitually is more liable to contract disease and less liable to throw it off than one who abstains from its use. A case 368 YOUNG folks' physiology recently occurred of a German brewer, apparently healthy and robust, who accidentally stuck a small sliver in his hand. Soon his arm began to swell and be painful, and the pain and swelling extended to the entire body, and resulted in death. The symptoms were clearly those of a bad condition of the blood, and no other explanation could be given than poison- ing by the use of lager beer." Note 12. — Prof. H. A. Hare, of the University of Penn- sylvania, made seventeen experiments, and every one of them very clearly showed that the beer retarded both the salivary and gastric digestion. Prof. Duggan, of Johns Hopkins University, found that alcohol in any form retarded the digestion of starch in a marked degree. Prof. Paul Bert ascertained that even small doses of spirits delayed digestion for the first two hours till absorption of the liquor had been mostly effected. When Dr. Beaumont was experimenting on Alexis St. Martin he gave him a glass of gin, when the digestive process was at once arrested, and did not begin again until after the absorption of the spirit, after which it was slowly renewed and tardily finished. " It is an entirely false idea that alcohol acts as an aid to digestion." — Dr. B. W. Richardson. " It is commonly thought that alcoholic drinks act as aids to digestion. In reality, it would appear that the contrary is the case. Any one may make the observation on himself that a meal without alcohol is more quickly followed by hun- ger than when alcohol is taken. The inhibitory influence of alcohol on digestion has been observed on a patient with a gastric fistula, on several other persons by the aid of the stomach pump, and by means of numerous other experi- NOTES 369 ments." — J^rof. G. Bunge, of the University of Bask, Switzerland. " The moderate use of strong drinks is always unhealthy, even when the body is in a healthy condition. It does not do any good to the digestion, but even interferes with that process ; for strong drink can only temporarily increase the feeling of hunger, but not in favor of digestion ; after which strong reaction must follow, and evils which are usually attrib- uted to other causes often result from their habitual use with moderate drinkers." — Six hundred physicians of the Netherlands. Note 13. — " The organ of the body which most frequently undergoes structural change from alcohol is the liver. The capacity of this organ for holding active substances in its cellular parts is one of its marked physiological distinctions. In instances of poisoning by arsenic, antimony, strychnine, and other poisonous compounds, we find, in conducting our analyses, the liver to be, as it were, the central depot of the foreign matter. It is practically the same in poisoning with alcohol. The liver of the confirmed alcoholic is probably never free from the influence of the poison ; it is too often sat- urated with it. The effect of the alcohol upon the liver is through the minute membranous or capsular structure of the organ upon which it acts to prevent the proper dialysis and free secre- tion. The organ at first becomes large from the distention of its vessels, the surcharge of fluid matter, and the thicken- ing of tissue. After a time there follow contraction of mem- brane and slow shrinking of the whole mass of the organ in its cellular parts, owing to the obstruction offered to the returning blood by the veins, and death is certain." — Dr. B. W. Richardson. 370 YOUNG FOLKS PHYSIOLOGY " The first effect of alcohol on the liver is to irritate it, just as it irritates the mouth and stomach, or, when applied strong enough, the skin. It causes distention of the blood- vessels and an accumulation of a larger amount of blood in them than there should be. This results in a swelling of the organ, partly from the larger quantity of blood in the vessels, and partly from effusion into it and an increase of tissue. This change in the liver causes a change in its action ; and its important work of preparing the food carried to it and making it ready for the uses of the body, its office of making blood, of changing waste matter so that it can be carried out of the system by other organs, and its work of secreting bile, are all imperfectly done. " This defective work leads to general derangement of the whole system. There is what is called biliousness — disturb- ance of the stomach, a coated tongue, foul breath, deranged bowels, headache, dizziness, dimness of sight, distressing dreams, a feeling in the side and stomach, and general uncom- fortable sensations. Notwithstanding that these unpleasant effects are so frequently produced by what are regarded as moderate quantities of wine, beer, or spirits, yet each drink, by its narcotic or soothing effect upon the brain and nerves, may make the person feel better for the time, just as the distress produced by opium-eating is temporarily relieved by repeating the dose. " But much more serious effects are sometimes produced by alcoholics ; and beer is more apt to act in the way about to be mentioned than whiskey. An accumulation of fat is often produced in the liver, causing its greater and more perma- nent enlargement, and impairing more permanently its action. When this is the case, stopping the drink does not produce the same rapid improvement as in the cases before mentioned. But where the fat is deposited between the proper liver ceils. NOTES 371 or structures, without taking the place of them, abstaining from drink may in time be followed by much improvement. There is another fatty change much worse than this where particles of fat take the place of the structure. This is called fatty degeneration, and where it occurs other organs are likely to be affected in a.dimilar way ; and this disease before a great while ends in death. When any portion of the liver tissue is changed into fat, that part cannot do its work, and as that change goes on action will cease and death will follow." — Dr. A. B. Palmer, late Dean of the Medical Depart- ment of the Michigan University. Note 14. — " It (tobacco) lessens the natural appetite, more or less impairs digestion, and induces constipation, while it irritates the mouth and throat, rendering it habitually congested, and destroying the purity of the voice. It in- duces an habitual sense of uneasiness and nervousness, with epigastric sinking, or tension, palpitation, hypochondriasis, neuralgia." — Prof Alfred Stille, Professor of Theory and Practice of Medicine in the University of Pennsylvania. " Tobacco gives rise to debility of the stomach and nau- sea." — Dr. B. W. Richardson. Note 15. — "Alcohol even in small quantities acts on the nerve pabulum in the blood, preventing its taking up oxygen and exhaling carbonic acid." — Dr. George Harley, F.R.S. " Alcohol stimulates the blood discs to an increased and unnatural contraction, which hurries them to the last stage of development — that is, induces their premature decay and death. The coloring matter is dissolved out of them and the pale discs lose their vitality, whence less oxygen can be absorbed." — Prof. Shultz. " In the ordinary use of alcoholic drinks enough alcohol is 372 YOUNG FOLKS PHYSIOLOGY not taken to produce death by coagulation of the albumen of the blood, but this affords no warrant for assuming that the lesser quantity is neutral or inactive. . . . Just to the extent in which it is present it must exert an unhealthy, abnormal influence upon the albumen." — Prof. E. L. Youmans. " With all parts of the blood, with the water, fibrine, albu- men, salts, fatty matter, and corpuscles, the alcohol comes in contact when it enters the blood, and, if it be in sufficient quantity, it produces disturbing action. I have watched this disturbance very carefully on the blood corpuscles ; for in some animals we can see these floating along during life, and we can also observe them from men who are under the influence of alcohol by removing a speck of blood and examining it with the microscope. The action of alcohol, when it is observable, is varied. It may cause the corpuscles to run too closely together and to adhere in rolls ; it may modify the outline, making the clear-defined, smooth, outer edge irregular or crenate, or even star-like ; it may change the round corpuscles into the oval form, or, in very extreme cases, it may produce what I may call a truncated form of corpuscles, in which the change is so great that if we did not trace it through all its stages, we should be puzzled to know whether the object looked at were indeed a blood-cell. All these changes are due to the action of the spirit on the water contained in the corpuscles, — upon the capacity of the spirit to extract water from them. During every stage of modification of corpuscle thus described, their function to absorb and fix gases is impaired, and when the aggregation of cells in masses is great, other difficulties arise, for the cells united together pass less easily than they should through the minute vessels of the lungs and of the general circulation and impede the current, by which local injury is produced." — Dr. B. W. Richardson, NOTES. 373 Note i6. — " Within the last few years experiments of the most exact and conclusive character have been made by skilled investigators, to determine the action of alcohol on the hearts of animals. . . . Among the most careful and skilful experiments on this subject are those of Drs. Sidney Ringer and Harrington Gainsbury of London. . . . These experiments made upon the hearts of frogs were instituted for the purpose of determining the comparative effects of the different alcohols in their direct action upon that organ. It was found that all the alcohols (including common alcohol, the active principle in all our liquors) diminished the force of the heart's action, and arrested it in a longer or shorter time, in exact proportion to the strength of the respective articles and the quantity applied. A long series of experiments furnished the same results and demonstrated their correctness. Common alcohol is weaker and lighter than some of the other rarer alcohols, but heavier and stronger than others ; but the effect in character was the same in all, differing only in degree. These eminent experi- menters, in closing the report on these articles, declared that, ' by their direct action upon the cardiac tissue, these drugs are clearly paralyzants ' (and not stimulating), and that this appears to be the case from the outset, no stage of increased force or contraction preceding. Prof. Martin, of Johns Hopkins University, who has written an excellent work on physiology, and who stands among the very highest in this country as an experimental physiologist, has made experiments with the view of determining the precise effect of common alcohol, when in the blood in cer- tain proportions, upon that organ. The results of these experiments have not been contradicted by any other experi- ments of a similar character, and they conclusively prove that the direct action of alcohol on the heart is paralyzing and not stimulating. 374 YOUNG FOLKS PHYSIOLOGY " It is true that alcohol often, indeed generally, increases the frequency of the heart's action, but not its force, when in a previously healthy state ; except perhaps in cases where it excites feverishness, which is a diseased condition. Great frequency of the pulse is an evidence of weakness rather than of strength." — Dr. A. B. Palmer. Note 17. — -" Tobacco-smoking of ten causes an intermit- tent pulse. Out of eighty-one smokers examined, twenty- three presented an intermittent pulse, independent of any cardiac lesion. This intermittency disappeared when the habit of smoking was abandoned. Among children from nine to fifteen years of age, smoking undoubtedly caused palpitation, intermittent pulse, and chloro-anama. The irregularity of the heart's action, which tobacco causes, is one of its most conspicuous effects. Candidates are annu- ally rejected for cardiac disturbances, who have subsequently admitted the use of tobacco, and the annual physical exami- nation of cadets reveals a large number of irritable hearts (tobacco hearts) among boys, who had no such trouble when they entered school. Among the applicants for enlistment as apprentices in the navy during the year 1879, ^^^ '"^ ^ thousand were rejected for functional lesions of the heart, indicating tobacco poisoning." Dr. Frangel, of Berlin, says that in his country, " while even immoderate smoking may appear to agree with persons for many years, suddenly, and without any other assignable cause, trouble with the heart begins, and a physician is consulted. These troubles seldom begin until the smoker has passed his thirteenth year, and usually appear at an age between fifty and sixty." APPENDIX LIGHT GYMNASTIC EXERCISES Value of Physical Exercises. — In preceding chap- ters [Chapters III. and IV.] of this book we have discussed the importance of physical exercises, and have alluded to the value of light gymnastics as cheap and conven- ient means of giving muscular strength and vigor to all parts of the body. It was claimed that children should be trained every day at home or at school in the use of free gymnastics, light wooden dumb-bells, rings, and so on. We learned that a daily exercise of this kind would do much to develop feeble and narrow chests, and to check the tendency to curvature of the spine and round shoulders so com- mon with school children. The study of physiology should do much to arouse the attention of teachers and pupils to the fact that physical culture is important and useful. The preced- ing sections of this book, therefore, can be utilized to impress upon the minds of young people the value of some kind of gymnastic training. 375 376 YOUNG folks' physiology For the benefit of those teachers who may wish to encourage their pupils to take an interest in the matter of physical culture, the following simple gymnastic exercises have been arranged. They are merely intro- ductory to more extended exercises. They may be easily abridged, extended, or modified as may be thought best. These exercises are not new or novel. They have been carefully selected and thoroughly tested in the schoolroom, and can be practised by any pupil in ordinary health without any fear of injury. Hints for Practice. — Gymnastic exercises should be practised with regularity and moderation. An exer- cise of fifteen or twenty minutes, once or twice a day, is enough. The various movements should be executed steadily and gradually and never in a spas- modic sort of way. They should be performed with attention, force of will, and energy. Slowly at first, after a time, practice will give vigor and precision. Avoid all exposure and draughts between and after the exercises. A wholesome fatigue may be felt, but not weariness or exhaustion. Let the practice be dis- continued for a time if it results in dizziness, nausea, and pains in the back or side. Do not practise too soon after eating a full meal, but rather one hour or more before a meal. Do not have the clothing too tight about the neck, chest, or abdomen during the exercise. Note. — These exercises have been compiled and rearranged from Lucy B. Hunt's " Handbook of Light Gymnastics" [price 50 cents], a most excellent and practical maunal for teachers. With the aid of this excellent httle book, the teacher can easily arrange more extended and complicated exercises, suited to the special need of his own school or class. APPENDIX 377 EXERCISES I. FREE GYMNASTICS. Position. — Stand with heels together, hips and shoulders back, hands firmly closed and well back upon the chest. Directions. — Each number fills a strain of music except when otherwise specified. Keep the heels together and hips back, unless the exercise otherwise directs. The arms overhead should always be with elbows unbent. These exercises should be taken slowly and with caution at first. As the strength increases, greater rapidity and force should be employed. Music for the free gymnastics should be either in galop or polka time. EXERCISE I. 1. Thrust right hand down twice, left twice, alter- nately twice, together twice. 2. Repeat No. i, only thrust hands out at sides in- stead of down. 3. Repeat No. i, thrusting hands directly up. 4. Repeat No. i, thrusting hands from shoulders directly forward. EXERCISE 2. 5. Right hand down once, left once, then clap hands through rest of the strain. 6. Same exercise, out at sides. 7. Same exercise, directly up. 8. Same exercise, out in front. 378 YOUNG folks' physiology EXERCISE 3. 9. Hands on the hips, step with right foot forward, then diagonally forward, directly at side, diagonally Fig. 98. Fig. gg. back, directly back, cross back of left, cross again still farther back ; lastly cross in front of left foot, return- ing to position after each step. 10. Repeat No. 9, with left foot. EXERCISE 4. 11. Stamp with right foot forward three times, advancing each time, then left three times. Stamp three times back with right foot, same with left. 12. Repeat No. 1 1. APPENDIX 379 EXERCISE 5. 13. Hands still on hips twist body alternately to right and left, twice each ; four beats of music. 14. Bend body alternate- ly to right and left, four beats of music finishing the strain. EXERCISE 6. 15. Bend body alternate- ly forward and back, twice each. 16. Bend body first y^}/'^ Fig. i right, then back, left, front ; reverse, left, back, right, front, finishing the strain. 17. Same as No. 13, only twist the head. 18. Same as No. 14, only bend the head instead of the body. EXERCISE 7. 19. Same as No. 15, with head only. 20. Like No. 16, bend head instead of body, right back, left, front, then reverse. EXERCISE 8. 21. Arms extended in front, bring them forcibly back to chest eight times. 22. Arms again extended, raise right hand twice without bending the elbow, then left twice, alternately twice, together twice. 38o YOUNG FOLKS PHYSIOLOGY EXERCISE 9. 23. Hands closed on chest, thrust down, out, up, and in front, twisting the arms each thrust ; repeat. 24. Thrust hands from chest toward floor without bending the knees, stop on chest, then over head, rising on' toes, and opening hands at each thrust, continue in half time through strain. 25. Cross left foot over right, at same time touching fingers over head ; then right foot over left, alternately in half time through the strain. EXERCISE ID. 26. Stamp left foot, then right, charge diagonally for- ward with right foot, bend and straighten right knee, at the same time carrying arms back from horizontal in front. When the arms are extended in front, the hands should be the width of the shoulders apart. 27. Repeat this exercise on the left side. Fig. 1 II. EXERCISES WITH DUMB-BELLS. Position. — Heels together, hips and shoulders back, bells down at sides. One-half of each strain of music is given to the exercise, the other half to what is called "the attitude." In taking these attitudes the APPENDIX 381 bells are brought first to the chest ; then, unless other- wise specified, placed upon the hips. Directions. — Step carefully but quickly to all the attitudes. Rest oftener than in the other exercises. Use too light rather than too heavy dumb-bells. Old-fashioned waltzes, like the " Boston Dip," are best for these exercises. Scotch airs, and airs from popular operas in this time, can easily be adapted by a skilful musician. EXERCISE II. 28. Hands down at sides, palms in front, turn bells four times, bringing them to chest on fourth accented beat. Attitude : Step diagonally for- ward with right foot, carrying hands to hips, looking over right shoulder. 29. Elbows at sides, turn bells just half-way round four times. Attitude: Step diagonally forward with left foot, looking over left shoulder. 30. Arms extended at sides, turn bells four times. Attitude : Step diagonally back with right foot, look- ing over right shoulder. 31. Arms extended over head, palms in front, turn bells four times.- Attitude: Step diagonally back with left foot, looking over left shoulder. 382 YOUNG FOLKS PHYSIOLOGY EXERCISE 12. 32. Bells far back on chest, thrust both down, out at sides, up, and out in front. Attitude : Turn to the right, throw arms up at side without bending the knees. The bells in this attitude should be exactly horizontal and parallel. 33. Repeat No. 32, turning to the left and throwing the arms up on left side. Attitude : Repeat attitude No. 32. EXERCISE 13. 34- Drop bells at sides, right hand up to armpit once, left once, together twice. Attitude: Drop to sitting position, bells touching the floor, rest through the remainder of the strain. EXERCISE 14. 35- Bells on shoul- ders, thrust each up once, both together Attitude: Rise on toes, palms forward, bells parallel. 36. Arms extended in front, turn four times. Attitude: Step diagonally forward with right foot, right hand on hip, looking back at left bell, which is extended in left hand. APPENDIX 383 EXERCISE 15. 37. Arms extended sideways at a:i angle of forty-five degrees, turn bells four times. Attitude: Step forward with left foot, left hand on hip, looking back at right bell, which is extended in right hand. EXERCISE 16. 38. Bells on chest, right hand down, then up, left hand the same. Attitude: Turn body to right, thrust right hand obliquely up, palm up ; left hand obliquely down, palm down. EXERCISE 17. 39- Bells on chest, right hand up, left down ; reverse, then both down, both up. Attitude: Turn to left, thrust hands up and down as in No. 38. EXERCISE i8. 40. Arms extended in front, palms opposite, right hand up once, left the same, both together up twice. This should he done without bending the elbows. Attitude: Step diagonally forward with right foot, the body and head thrown forward, and arms thrown wide apart. 41. Repeat No. 40. Attitude: Repeat attitude No. 40, on the left side. EXERCISE 19. 42. Arms extended at sides, right arm up once, left once, both twice, without bending the knees. 384 YOUNG FOLKS PHYSIOLOGY Attitude : Step diagonally back with rigiit foot, right hand up, with bell perpendicular, left hand on hip. 43. Repeat No. 42. Attitude: Repeat attitude on left side. EXERCISE 20. 44. Arms extended, with bells parallel in front, bring the bells back forcibly upon the chest four times. Attitude: Fold the arms with bells closely pressed against the chest, and bend back slowly from the waist. III. EXERCISE WITH WANDS. Directions. — These exercises are performed in couples, partners facing each other about three feet apart ; the one standing on right of teacher on platform holding both rings. Schottische time is the best, but slow marches and quicksteps can be used. Always select a wand just long enough to reach the armpit when placed on the floor at one's side. All exercises from behind the head or back should be taken with caution, and avoided altogether by those with weak backs. Note. — For several of' the illustrations in this chapter, the author is indebted to the publishers (Educational Publishing Company, Boston), for kind permission to take them from their excellent book called " Ladies' Home Calisthenics." APPENDIX 385 Position — Heels together, hips and shoulders well back. The wand is held in front of the right shoulder, till first signal from the piano, which consists of three chords struck with both hands, the first being the length of the other two ; then drop it horizontally in front of the body. At second signal raise the wand till the arms are extended in horizontal position in front of body, place the hands so as to divide the wand into three equal parts. At third signal, carry ■-;::--::.llffft:::":™r"^:™~r:-::~~~----:^rr!=5^- the wand back to rx /V second position down in front. The , simplest of Strauss's waltzes must be used, or those of other com- posers similar in style. Directions. — In all exercises, turning back to back, be care- ful and not pull sud- denly, and never let go the ring before the word is given. Always stand at such a distance from next couple that there can be no hitting of rings. The rings should always be strongly made, and about six inches in diameter. Fi&. 103. 386 YOUNG folks' physiology EXERCISE 21. 45- Raise the wand to chin four times, keeping elbows high, last time carry it above the head, then bring down under chin four times. 46. Carry wand from above the head nearly to floor, four times,.without bending knees or elbows, then down back of the neck four times. 47. Carry wand from above the head to chin, and then back of neck, alternately four times each. ^ EXERCISE 22. 48. Wand over head. On first beat, carry right hand to right end of wand, on second beat, left hand to left end, then carry hand back of head to hips, six times, keeping elbows stiff. 49- Carry wand back from above head down nearly to floor ; and then back to hips, four times, alternately four times each. 50. Carry wand from above the head to right and left sides alternately eight times, keeping elbows stiff, and stopping exactly over head each time. EXERCISE 23. 51. On first beat, let go wand with left hand, place end of wand on floor between feet. On second beat place wand on floor at arm's length, diagonally forward on right side. Step with right foot to wand through rest of strain, keeping right arm, left knee, and wand perfectly straight. 52. Repeat No. 51 on left side. APPENDIX 387 53. Repeat No. 51, keeping the foot stationary, the knee bending with each accent^ beat. 54. Repeat No. 53 on left side. EXERCISE 24. 55. Arms horizontal in front, wand held perpendicu- larly, bring wand back to chest eight times, keeping elbows high. 56. Wand and arms in same position, bring wand to right and left shoulders alternately four times each. In passing the wand from one side to the j*^,....rf5,..-......-...................,„..-,..,,,^ other, raise the arms straight to a horizontal position in front. EXERCISE 25. 57- Hands in front of chest, point wand diagonally forward at an angle of forty-five degrees, first to the right, then to the left alternately through strain, making the change of hands just in front of chin. 58. With wand point- ing in the same direc- tion as in last exercise, step diagonally forward with right and left foot alternately through strain. p-lG. 104. 388 YOUNG folks' physiology 59. Repeat No. 58, only step back instead of forward, leading with left foot instead of right, keeping wand pointing forward. EXERCISE 26. 60. Wand horizontal over head, right hand in front, reverse position, bringing left hand in front, on half time through strain. 61. Same position, right face, bend forward bringing wand to perpendicular on right side, four times. 62. Repeat No. 61 on left side. EXERCISE 27. 63. On first beat, put left etid of wand on floor in front of feet ; on second beat, carry wand at arm's length in front, charge right foot to wand twice, left four times, changing hands and feet at same time. 64. Right foot back four times, right hand on wand, same with left hand and foot. 65. Right foot forward and back four times, left the same, holding wand in same position as last exercise. 66. Both hands on wand in front, right foot forward, left back at the same time, reverse and repeat. IV. EXERCISES WITH RINGS. EXERCISE 28. 67. On first beat of music, the ring in right hand is extended, and grasped by partner's right hand. Second beat, right feet together, toes touching ; on third beat left feet back at right angles with right feet, with left APPENDIX 389 hands upon hips. Turn the ring over half-way and then back to place through rest of strain, keeping perfect time. 68. Repeat No. 6^, only use left hand and left foot instead of right. 69. Repeat No 6"], only first join both hands, on second beat right feet together, third beat step back as before, turn rings through strain. 70. Repeat No 69, with both hands joined and left feet touch- ing, right feet back, turn rings through strain. EXERCISE 29. 71. On first beat, turn back to back, on second beat left feet to- gether, charge directly forward with right feet ; head and shoul- ders well thrown back, pull evenly with partner, and turn the rings through strain. 72. Repeat No. 71, with right feet together, left out in front, turn rings through strain. EXERCISE 30. 73. On first beat, turn face to face, on second beat raise arms above head, then lower rings without bend- ing knees, looking alternately to right and left of partner through strain. 74. First beat, lift arms towards platform, high up at side, the others low down at the opposite side,' carry them alternately up and down through half the strain, then both together, half a strain. 390 YOUNG folks' physiology EXERCISE 31. 75. First beat, turn back to back, charge diagonally forward with right and left feet alternately through strain. 76. First beat, turn face to face, place left foot inside partner's left, short step back with right foot at right angles with the left. Rings over head held firmly, arms perfectly straight, sway alternately through the strain. 77. Repeat No "jS, with right feet together instead .of left. EXERCISE 32. 78. First beat, turn back to back, charge up and down the hall alternately twice each ; charge with right feet at same time, then left feet at same time, alter- nately through rest of strain. 79. First beat, turn face to face, repeat No. 78. Books for Study and Reference. — In addition to other works on physical culture mentioned in this book, the student will find the follow- ing books of much value and interest: i. Lagrange's Physiology of Exercise. 2. Anderson's Light Gymnastics. 3. Blaikie's How to get Strong. 4. Enebuske's Gymnastic Days' Orders. 5. Mara Pratt's New Calisthenics. 6. Mara Pratt's Supplement to New Calisthenics. 7. Roberts's Gymnastic Exercises Classified. 8. Maclaren's Physical Education. 9. Ladies' Home Calisthenics. Reference has been made to several standard works on the Swedish system on page 65. GLOSSARY The ordinary use of a g^lossary is to explain, in some detail, many of the more diffi- cult words used in the text. The pupil will, however, find it an admirable and profitable review exercise, to drill himself on the spelling, derivation, and defini- tion of each word, mastering a few ^vords every day. Ab-do'men ( Latin abdo, abdere, to conceal). The largest cavity of the body, containing the liver, stomach, intestines, etc. Ab-sor'bents (L. absorbere, to suck up). The vessels which take part in the process of absorption. Ab-sorp'tion. The process of suck- ing up nutritive or waste matters by the blood-vessels or lym- phatics. Ac-com-mo-da'tion of the Eye. The alteration in the shape of the crystalline lens, which accommo- dates, or adjusts, the eye for near and remote vision. Ac-e-tab'u-lum (L. acetum, vine- gar). A little cup used by the ancients for holding vinegar ; ap- plied, in anatomy, to the round cavity in which the hip-bone re- ceives the head of the femur. Ac'id (L. acidus, from acere, to be sour). A substance usually sour, sharp, or biting to the taste. Ad'am's Ap'ple. An angular pro- jection of cartilage in the front of the neck. It is particularly prom- inent in males, and is so called from a notion that it was caused by the apple sticking in the throat of our first parent. Al-bu'men, or Albumin ( L. albus, white). An animal substance re- sembling the white of an egg. Al-bu'tnin-oids. A class of sub- stances resembling albumen : they may be derived from either the animal or vegetable kingdoms. Al'i-ment {L.alo, to nourish). That which affords nourishment ; food. Al-i-ment'a-ry Ca-nal (from a/i- meni). A long tube in which the food is digested, or prepared for reception into the blood. Al'ka-li (Arabic, al kali, the soda plant). A name given to certain substances, such as soda, potash, and the like, which have the power of combining with acids. 39' 392 GLOSSARY An-aes-thet'ics (Greek an, without, aisthesia, feeling). Those medi- cinal agents which prevent the feeling of pain, such as chloro- form, ether, laughing-gas, etc. A-nat'o-my (Gr. anatemno, to cut up). The science which de- scribes the structure of living things. A-or'ta (Gr. aeirein, to lift up). The largest artery of the body, arising from the left ventricle of the heart. The name was first applied to the two large branches of the trachea, which appear to be lifted up by the heart. A'que-ous Humor (L. aqua, water). The watery fluid occu- pying the space between the cor- nea and crystalline lens of the eye. A-rach'noid Mem'brane (Gr. arachne, a spider, and eidos, like). The thin covering of the brain and spinal cord, between the dura mater and the pia mater. Ar'bor Vi'tae (L.). Literally, " the tree of life ; " a name given to the peculiar appearance presented by a section of the cerebellum. Ar'ter-y (Gr. aer, air, and tereo, to contain). A vessel by which blood is carried away from the heart. It was supposed by the ancients to contain only air; hence the name. Ar-tic-u-la'tion (L. articulo, to form a joint). The more or less movable union of bones, etc. ; a joint. A-ryt'e-noid Car'ti-la-ges (Gr. arutaina, a ladle). Two small cartilages of the larynx, resem- bling the mouth of a pitcher. As-sim-i-la'tion (L. ad, to, and similis, like). The conversion of food into living tissue. Au'di-to-ry (L. audita, to hear) Nerve. One of the crania! nerves : it is the special nerve of hearing. Au'ri-cle (L. auricula, a little ear). A cavity of the heart. Bac-te'ria (Gr. baktron, a staff). A microscopic, vegetable organism ; certain species are active agents in fermentation, while others appear to be the cause of infec- tious diseases. Bile. The gall, or peculiar secre- tion of the liver ; a viscid, yellow- ish fluid, and very bitter to the taste. Blad'der (Saxon, bleddra, a blad- der, a goblet). A bag, or sac, serving as receptacle of some secreted fluid ; as i\i^ gall-bladder, etc. In common language, the receptacle of the urine in man and other animals. Blight's Dis-ease'. A group of diseases of the kidney, first de- scribed by Dr. Bright. Bronch'i (Gr. bronchos, windpipe). The two first divisions, or branches, of the trachea : one enters each lung. fironch'i-al Tubes. The smaller branches of the trachea within the substance of the lungs, ter- minating in the air-cells. Bronch-i'tis (from bronchos, and -itis, a suffix signifying inflam- mation of the larger bronchial GLOSSARY 393 tubes ; a " cold " affecting the lungs. Bun'ion. An enlargement and in- flammation at the first joint of the great toe. Cal'lus (L. calleo, to be thick- sltinned). Any excessive hard- ness of the skin, caused by friction or pressure. Ca-nal' (L. canalis, a canal). In the body, any tube or passage. Ca'pil-la-ry (L. capillus, hair). The smallest blood-vessels, so called because they are so tiny. Car-bon'ic A'cid. The gas which is present in the air breathed out from the lungs ; a was'te product of the animal kingdom, and a food of the vegetable kingdom. More correctly called Carbon Di- oxide. Car'diac (Gr. kardia, the heart). The cardiac orifice of the stom- ach is the upper one, and is near the heart; hence its name. Car-niv'o-rous (L. ca'ro, flesh, and vo'ro, to devour). Subsisting upon flesh. Car'ron Oil. A mi.xture of equal parts of linseed-oil and lime- water, so called because first used at the Carron Iron Works in Scotland. Car'ti-lage. A tough but flexible material, forming a part of the joints, air-passages, nostrils, ear ; gristle. Ca'se-ine (L. ca'sens, cheese). The albuminoid substance of milk: it forms the basis of cheese. Ca-tarrh'. An inflammation of a mucous membrane. Cell (L. cella, a storeroom). The name of the tiny microscopic ele- ments, which, with slender threads or fibres, make up most of the body : they were once believed to be little hollow chambers; hence the name. Cem'ent. The substance which forms the outer part of the fang of a tooth. Cer-e-bel'lum (diminutive for cer'- ebrum, the brain). The little brain, situated beneath the poste- rior third of the cerebrum. Cer'e-brum (L.). The brain proper, occupying the entire upper portion of the skull. It is nearly divided into two equal parts, called " hemispheres," by a cleft extending from before backward. Chlo'ral. A powerful drug used by physicians to induce sleep. Cho'roid (Gr. chorion, skin, and eidos, form). The middle coat of the eyeball. Chyle (Gr. chulos, juice). The milk-like fluid formed by the di- gestion of fatty articles of food in the intestines. Chyme (Gr. chumos, juice). The pulpy liquid formed by digestion in the stomach. Cil'i-a (pi. of cil'i-utn, an eyelash). Minute hair-like processes found upon the cells of the air-passages and other parts that are com- monly moist. Cir-cu-la'tion (L. cir'culus, a circle). The course of the blood through the blood-vessels of the body. 394 GLOSSARY Co-ag-u-la'tion (L. coag'ulo, to cur- dle). Applied to the process by which the blood clots or solidifies. Coch'le-a (L. cock'lea, a snail- shell). The spiral cavity of the internal ear. Conch'a (Gr. konche^ a mussel- ' shell). The shell-shaped portion of the external ear. Con-ges'tion (L. con, together, and gero, to bring). An unnatural gathering of blood in any part of the body. Con-junc-ti'va (L. con, together, and jun'go, to join). A thin layer of mucous membrane which lines the eyelids, and covers the front of the eyeball, thus joining the latter to the lids. Con-nect'ive Tis'sue. The net- Work which connects the minute parts of most of the structures of the body. Con-sti-pa'tion (L. con, together, and stipo, to crowd close). Cos- tiveness ; tardiness in evacuating the bowels. Con-sump'tion (L. consumo, to consume.) A disease of the lungs, attended with a fever and cough, and causing a gradual decay of the bodily powers. The medical name \% phthisis. Con-trac-tiri-ty (L. con, together, and tra'ho, to draw). The prop- erty of a muscle which enables it to contract, or draw its extremi- ties closer together. Con-vo-lu'tions (L. con, together, and vol'vo, to roll). The tortuous foldings of the external surface of the brain. Con-vul'sion (L. convel'lo, to pull together). A more or less vio- lent agitation of the limbs or body. Corn (L. cor'nu, a horn). A small portion of the outer skin, of horn- like hardness. Cor'ne-a (L. cor'nu, a horn). The transparent, horn-like substance which covers a part of the front of the eyeball. Cor'pus-cles Blood. (L. dim. of cor'pus, a body). The small disks which give to the blood its red color : the white cori^uscles are globular and larger. Cos-met'ic (Gr. kosmeo, to adorn). Applied to articles which are supposed to increase the beauty of the skin. Cra'ni-al (L. cra'nium, the skull). Pertaining to the skull. Cri'coid (Gr. kri'kos, a ring, and eidos, form). A cartilage of the larynx, resembling a seal-ring in shape. Crys'tal-line Lens CL. crystal' Item, a crystal). One of the so-called humors of the eye; a double- convex body situated in the front part of the eyeball. Cu'ti-cle (L. dim. of cu'tis the skin). The scarf-skin; also called the epider'mis, Cu'tis (Gr. sktttos, a skin, or hide). The true skin, lying beneath the cuticle ; also called the der'mis. Dan'druff. The small scales, or particles, which separate from the scarf-skin of the scalp. De-cus-sa'tion (L. decus'sis, the Roman numeral ten, X.). A re- GLOSSARY 395 ciprocal crossing of fibres from side to side. De-gen-er-a'tion (L. degenerare, to grow worse; to deteriorate). A cliange in the structure of any organ which makes it less fit to perform its duty or function. Deg-lu-ti'tion (L. deglutire, to swallow down). The act, or process, of swallowing. De-lir'i-um. A state in which the ideas of a person are wild, irregu- lar, and unconnected. Den'tine ( L. dens, dentis, a tooth ) . The hard substance which forms most of a tooth ; ivory. De-o-do-ri'zer. An agent which corrects any foul or unwholesome odor. Di'a-phragm (Gr. diaphrasso, to divide by a partition). A large, thin muscle which separates the cavity of the chest from the abdomen. Di-ar-rhce'a (Gr. diarrhein, to flow through). An unnaturally fre- quent and liquid evacuation of the bowels. Dif-fus'ion of Gases. The power of gases to become intimately mingled. Dis-in-fect'ant. Agents used to destroy the causes of infection. Dis-lo-ca'tion (L. dislocare, to put out of place). The name of an injury to a joint, in which the bones are displaced or forced out of their sockets. Dis-sec'tion (L. dis, apart, and seco, to cut). The cutting up of an animal in order to learn its structure. Duct (L. du'co, to lead). A narrow tube : the thoracic duct is the main trunk of the absorbent vessels. Du-o-de'num (L. duode'ni, twelve). The first division of the small intestines, about twelve fingers'- breadth long. Dys-pep'si-a (Gr. dus, ill, peptein, to digest). A condition of the alimentary canal in which it di- gests imperfectly. Indigestion. El'e-ment. One of the simplest parts of which anything consists. E-met'ic (Gr. emeo, to vomit). Having power to excite vomiting. Also, a medicine which causes vomiting. E-mul'sion (L emulgere, to milk). Oil in a finely divided state, sus- pended in water. En-am'el (French, hnail). The dense material which covers the crown of a tooth. En'e-ma (L. enema, a clyster). An injection thrown into the rectum, as a medicine, or to impart nourishment. Ep-i-glot'tis (Gr. epi, upon, and glottis, the entrance to the wind- pipe). A leaf-shaped piece of cartilage which covers the top of the larynx during the act of swallowing. Ep'i-lep-sy (Gr. epilepsis, a seiz- ure). A nervous disease accom- panied by fits in which conscious- ness is lost. The falling sick- ness. Eu-sta'chi-an (from an Italian ana- tomist named Eustachi). The tube which leads from the throat to the middle ear, or tympanum. 396 GLOSSARY Ex-cre'tion (L. excer'no, to sepa- rate). The separation from the blood of the waste matters of the body; also, the materials ex- creted. Ex-pi-ra'tion (L. expi'ro, to breathe out). The act of forcing air out of the lungs. Ex-ten'sion (L. ex, out, and len'do, to stretch). The act of restoring a limb, etc., to its natural position after it has been flexed, or bent ; the opposite oi flexion. Fau'ces. The part of the mouth which opens into the pharynx. Fer'ment. That which causes fermentation, as yeast. Fer-men-ta'tion (L. fernientum, boiling, hot). The process of un- dergoing an effervescent change, as by the action of yeast; in a wider sense, the change of organ- ized substances into new com- pounds by the action of a fer- ment. It differs in kind according to the nature of the ferment which causes it. Fe'nes-tra (L.). Literally, a win- dow; the opening between the middle and internal ear. Fi'bre ('L.fibra, a filament). One of the tiny threads of which many parts o£ the uody are com- posed. Fi'brine (L. fi'bra, a fibre). An albuminoid substance found in the blood. Flex'ion (L fl^cto, to bend). The act of bending a limb, etc. Fol'li-cle (L. dim. of fol'lis, a money-bag). A little pouch, or depression, in a membrane. Fo-men-ta'tion (L./o'wo, to keep warm). The application of any warm, soft medicinal subtance to some part of the body by which the vessels are relaxed. Fo-ra'men. A hole, or aperture. Fu-mi-ga'tion (h.fu'migo, to per- fume a place). The use of cer- tain fumes to counteract conta- gious effluvia. Func'tion (L. futictio, a doing). The special duty of any organ of the body. Fun'gous Growths (L./un'gus, a mushroom). A low grade of vege- table life. Gan'gli-on (Gr. ganglion, a knot). A knot-like swelling in a nerve ; a smaller nerve-centre. Gas'tric (Gr. gaster, stomach). Pertaining to the stomach. Gel'a-tine {L.ge/o, to congeal). An animal substance which dissolves in hot water, and forms a jelly on cooling. Germ (L. germen, a sprout, bud). Disease germ ; a name applied to certain tiny bacterial organisms which have been demonstrated to be the cause of disease. Gland (L. glans, an acorn). An organ consisting of follicles and ducts, with numerous blood- vessels interwoven. Glot'tis (Gr. glotta, the tongue). The narrow opening between the vocal cords. Glu'ten. Literally, glue; the glu- tinous albuminoid ingredient of wheat. Groin. The lower part of the ab- domen just above each thigh. GLOSSARY •397- Gus-ta'tion (L. gusto, to taste). The sense of taste. Gus'ta-to-ry Nerve. The nerve of taste supplying the front part of the tongue, a branch of the " fifth " pair. Gym-nas'tics (Gr. gumnazo, to ex- ercise). The practice of athletic exercises. Hem'i-spheres (Gr. hemi, half, and sphaira, a sphere). Half a sphere, the lateral halves of the cere- brum, or brain proper. Hem'or-rhage (Gr. hai'ma, blood, and regnumi, to burst). Bleed- ing, or the loss of blood. He-pat'ic (Gr. hepar, the liver). Pertaining to the liver. Her-biv-o'rous (L. her'ba, an herb, and vo'ro, to devour). Applied to animals that subsist upon vege- table food. Hic'cough. A convulsive motion of some of the muscles used in breathing, accompanied by a shutting of the glottis. Hu'mor. Moisture ; the humors are transparent contents of the eyeball. Hy-dro-pho'bi-a (Gr. Imdor, water, and phobeomai, to fear). A dis- ease caused by the bite of a rabid dog or other animal. Hy'gi-ene (Gr. hygieia, health). The art of preserving health, and preventing disease. In-ci'sor (L. inci'do, to cut). Ap- plied to the four front teeth of both jaws, which have sharp, cut- ting edges. In'cus. An anvil ; the name of one of the bones of the middle ear. In'di-an Hemp. The common name of Cannabis Indica, an in- toxicating . drug, known as hasheesh, and many other names, in Eastern countries. In-fe'ri-or Ve'na Ca'va (L.). Lower hollow vein; the chief vein of the lower part of the body. In-flam-ma'tion (L. prefix in, and flammo, to flame). A redness or swelling of any part of the body, with heat and pain. In-sal-i-va'tion (L. in, and sali'va, the fluid of the mouth). The mingling of the saliva with the food during the act of chewing. In-spi-ra'tion (L. inspi'ro, spira'- turn, to breathe in). The act of drawing in the breath. In-teg'u-ment (L. itite'go, to cover). The skin, or outer covering of the body. In-tes'tine (L. in'tus, within). The part of the alimentary canal which is continuous with the lower end of the stomach; also called the bowels. I'ris (L. i'ris, the rainbow). The thin, muscular ring which lies be- tween the cornea and crystalline lens, and which gives the eye its special color. Jaun'dice {Fr.Jaunisse, yellow). A disorder in which the skin and eyes assume a yellowish color. Lab'y-rinth. The internal ear, so named from its many windings. Lach'ry-mal Ap-pa-ra'tus (L. lach'ryma, a tear). The organs for forming and carrying away the tears. .39^ GLOSSARY Lac'te-als (L. lac, lac'tis, milk). The absorbent vessels of the small intestines. Lar'ynx. The cartilaginous tube situated at the top of the wind- pipe, or trachea; the organ of the voice. Lens. Literally, a lentil ; a jjiece of transparent glass or other substance so shaped as either to converge or disperse the rays of light. Lig'a-ment (L. li'go, to bind). A strong, fibrous material binding bones or other solid parts to- gether : it is especially necessary to give strength to joints. Lig'a-ture (L. ligo, to bind). A thread of some material used in tying a cut or injured artery. Lobe. A round, projecting part of an organ, as of the liver, lungs, or brain. Lymph (L. lym'fha, pure water). The watery fluid conveyed by the lymphatic vessels. Lym-phat'ic Ves'sels. A system of absorbent vessels. Mal'le-us. Literally, the mallet; one of the small bones of the middle ear. Mar'row. The soft, fatty sub- stance contained in the central cavities of the bones. Mas-ti-ca-tion (L. mas'tico, to chew). The act of cutting and grinding the food to pieces by means of the teeth. Me-a'tus (L. meare, to wander). A passage or channel. Me-dul'la Ob-lon-ga'ta. The " ob- long marrow," or nervous cord. which is continuous with the spinal cord within the skull. Mem-bra'na Tym'pan-i. Liter- ally, the membrane of the drum ; a delicate partition separating the outer from the middle ear ; it is sometimes incorrectly called the drum of the ear. Mem'brane. A thin layer of tis- sue serving to cover some part of the body. Mi'cro-scope (Gr. mikros, small, and skopeo, to look at). An opti- cal instrument which assists in the examination of minute ob- jects. Mi'crobe (Gr. mikros, little, and bios, life). A microscopic organ- ism particularly applied to bac- teria. Mo'lar (L. mo' la, a mill). The name applied to the three back teeth at each side of the jaw ; the grinders, or mill-like teeth. Mo'tor (L. mo'veo, mo'tum, to move). Causing motion; the name of those nerves which con- duct to the muscles the stimulus which causes them to contract. Mu'cous Membrane. The thin layer of tissue which covers those internal cavities or passages which communicate with the external air. Mu'cus. The glairy fluid which is secreted by mucous membranes, serving to keep them in a moist co4idition. My-o'pi-a (Gr. muo, to shut, and ops, the eye). A defect of vision dependent upon an eyeball that is too long, rendering distant ob- jects indistinct ; near-sight. GLOSSARY 399 Nar-cot'ic (Gr. narkoo, to be- numb). A medicine, which, in poisonous doses, produces stupor, convulsions, and sometimes death. Na'sal (L. na'sus, the nose). Per- taining to the nose. Nerve Cell. A minute, round, and ashen-gray cell found in the brain and other nervous centres. Nerve Fi'bre. An exceedingly slender thread of nervous tissue. Nos'tril (Anglo-Saxon, nosu, nose, and thyrl, a hole). One of the tvfo outer openings of the nose. Nu-cle'o-lus (diminutive of ««'- cleus). A little nucleus. Nu'cle-us (L. nux, a nut). A cen- tral part of any body, or that about which matter is collected. In anatomy, a cell within a cell. Nu-tri'tion (L. nu'trio, to nourish). The processes by which the nourishment of the body is accomplished. O-don'toid (Gr. odous, a tooth, eidos, shape). The name of the bony peg of the second vertebra, around which the first turns. CE-soph'a-gus. Literally, that which carries food. The tube leading from the throat to the stomach; the gullet. O-le-ag'i-nous (L. o'leum, oil). Of the nature of oil ; applied to an important group of food-princi- ples, — the fats. Ol-fac'to-ry (L. olfa'cio, to smell). Pertaining to the sense of smell. Op'tic (Gr. opto, to see). Pertain- ing to the sense of sight. Or'bit (L. or'bis, a circle). The bony socket or cavity in which the eyeball is situated. Or'gan (L. organum, an instrument or implement). A portion of the body having some special func- tion or duty. Os'se-ous (L. OS, a bone). Con- sisting of, or resembling, bone. Pal'ate (L. pala'tum, the palate). The roof of the mouth, consist- ing of the hard and soft palate. Pal-pi-ta'tion (L. palpitatio, a fre- quent or throbbing motion). A violent and irregular beating of the heart. Pa-pil'la. The name of the small elevations found on the skin and mucous membranes. Pa-ral'y-sis (Gr. paraluem, to loosen ; also, to disable). Loss of function, especially of motion or feeling. Palsy. Par'a-site. A plant or animal that grows or lives on another. Pa-tel'la (L. dim. ol pat'ina, a pan). The knee-pan. Pel'vis. Literally, a basin. The bony cavity at the lower part of the trunk. Pep'sin (Gr. pepto, to digest). The active principle of the gastric juice. Per-i-car'di-um (Gr. peri, about, and kardia, heart). The sac en- closing the heart. Per-i-os'te-um (Gr. peri, around, osteon, a bone). A fibrous mem- brane which surrounds the bones. Per-i-stal'tic Move'ments (Gr. peri, round, and stello, to send). The slow, wave-like movements of the stomach and intestines. 400 GLOSSARY Per-i-to-ne'um (Gr. periteino, to stretch around). The investing membrane of the stomach, intes- tines, and other abdominal organs. Per-spi-ra'tion (L. perspi'ro, to breathe through). The sweat. Pe'trous (Gr. peira, a, rock). The name of the hard portion of the temporal bone, in which is situ- ated the drum of the ear and labyrinth. Pha-lan'ges (Gr. phalmix, a body of soldiers closely arranged in ranks and files). The bones of the fingers and toes. Phar'ynx (Gr. pharunx, the throat). The cavity between the back of the mouth and gullet. Phys-i-ol'o-gy (Gr. phusis, nature, and logos, a discourse). The sci- ence of the functions of living, organized beings. Pi'a Ma'ter (L.). Literally, the tender mother; the innermost of the three coverings of the brain. It is thin and delicate ; hence the name. Pig'ment (L. pingo, to paint). Coloring-matter. Plas'ma (Gr. plasso, to mould). Anything formed or moulded. The liquid part of the blood. Pleu'ra (Gr. pleura, the side, also a rib). A membrane covering the lung, and lining the chest. Pleu'ri-sy. An inflammation af- fecting the pleura. Pneu-mo-gas'tric (Gr. pneumon, the lungs, and gaster, the stom- ach). It is the principal nerve of 'respiration ; also called the vagus, or wandering nerve. Pneu-mo'nia. An inflammation affecting the air-cells of the lungs. Poi'son (Fr. poison). Any sub- stance, which, when applied ex- ternally, or taken into the stom- ach or the blood, works such a change in the animal economy as to produce disease or death. Por'tal Vein (L. porta, a gate). The venous trunk formed by the union of all the veins coming from the intestines. It carries the blood to the liver. Pres-by-o'pi-a (Gr. presbus, old, and ops, the eye). A defect of the accommodation of the eye, caused by the hardening of the crystalline lens ; the " far-sight " of adults and aged persons. Proc'ess (L. proce'do, proces'sus, to proceed, to go forth). Any pro- jection from a surface ; also, a method of performance ; a pro- cedure. Pro'te-id (Gx.protos, first, and eidos, form). An element allied to ni- trogen ; a substance containing such elements ; an albuminoid. Pty'a-lin (Gr. ptualon, saliva). The peculiar organic ingredient of the saliva. Pul'mo-na-ry (L. pul'mo, pulmo- nis, the lungs). Pertaining to the lungs. Pulse (L. pel'lo, pul'sum, to beat). The striking of an artery against the finger, occasioned by the con- traction of the heart, commonly felt at the wrist. Pu'pil (L. pupil'la). The central, GLOSSARY 401 round opening in the iris, through which light passes into the inte- rior of the eye. Py-lo'rus (Gr. puloros, a gate- keeper). Tlie lower opening of the stomach, at the beginning of the small intestine. Re'flex (L. reflextts, turned back). The name given to involuntary movements produced by an exci- tation travelling along a sensory to a centre, where it is turned back or reflected along motor nerves. Re'nal (L. renes, the kidneys). Pertaining to the kidneys. Res-pi-ra'tion (L. respi'ro, to breathe frequently). The function of breathing, comprising two acts, — inspiration, or breathing in ; and expiration, or breathing out. Ret'i-na (L. re'te, a net). The in- nermost of the three tunics, or coats, of the eyeball, being an expansion of the optic nerve. Sac'cha-rine (L. sac'charum, sugar). Of the nature of sugar; applied to the group of food- substances which embraces the different varieties of sugar, starch, and gum. Sa-li'va. The moisture, or fluids, of the mouth, secreted by the salivary glands. The spittle. Scle-rot'ic (Gr. skleros, hard). The tough, fibrous, "outer coat of the eyeball. Se-ba'ceous (L. sebum, fat). Re- sembling fat; the name of the oily secretion by which the skin is kept flexible and soft. Se-cre'tion (L. secer'no, secre'tum, to separate). The process of separating from the blood some essential, important fluid; which fluid is also called a secretion. Sera-i-cir'cu-lar Ca-nals. Three canals in the internal ear. Sem-i-lu'nar (L. semi, half, luna, mooned). Shaped like a half- moon. Sen-sa'tion. The perception of an external impression by ths ner- vous system. Se'rum. The clear, watery fluid which separates from the clot of the blood. Sock'et (L. scccus, a kind of low- heeled shoe). An opening into which anything is fitted. Spasm (Gr. spasmos, convulsion). A sudden, violent, and involun- tary contraction of one or more muscles. Spe'cial Sense. A sense by which we receive particular sensations, differing from those of general sensibility ; such as those of sight, hearing, taste, and smell. Sprain. An injury to the liga- ments or tendons about a joint. Sta'pes. Literally, a stirrup; one of the small bones of the middle ear, shaped somewhat like a stirrup. Stim'u-lant (L. stimulo, to prick or goad on). An agent which causes an increase of vital activity in the body or any of its parts. Stri'a-ted (L. sirio, to furnish with channels). Marked with fine, parallel lines. Sub-cla'vi-an Vein (L. sub, under, 402 GLOSSARY and clavis, a key). The great vein bringing back the blood from the arm and side of the head ; so called because it is situated underneath the clavicle, or collar- bone. Su-pe'ri-or Ve'na Ca'va (L. upper hollow vein). The great vein of the upper part of the body. Sut'ure (L. sutura, a seam). The union of certain bones of the skull by the interlocking of jagged edges. Sym-pa-thet'ic Sys'tem of Nerves. A double chain of nervous ganglia, connected by numerous small nerves, situated chiefly in front of, and on each side of, the spinal column. Symp'tom (Gr. sun, with, and pipto, to fall). A sign, or token, of disease. Syn-ov'i-al (Gr. sun, with, oSn, an egg). The liquid which lubri- cates the joints; joint-oil. So called from its resemblance to the white of a raw egg. Sys-tem'ic. Belonging to the sys- - tern, or body, as a whole. Sys'to-le (Gr. sustello, to contract). The contraction of the heart by which the blood is expelled from that organ. Tac'tile (L. tac'tus, touch). Relat- ing to the sense of touch. Tar'tar. A hard crust which forms on the teeth, and is composed of salivary mucous, animal matter, and a compound of lime. Tem'po-ral (L. tem'pits, time, and tem'pora, the temples). Pertain- ing to the temples ; so called be- cause the hair begins to turn white with age in that portion of the scalp. Ten'don (L. ten'do, to stretch). The white, fibrous cord, or band, by which a muscle is attached to a bone ; a sinew. Tet'a-nus (Gr. teino, to stretch). A disease marked by jjersistent con- tractions of all or some of the voluntary muscles ; those of the jaw are sometimes solely affected ; the disorder is then termed locked-jaw. Tho'rax (Gr. thorax, a breast- plate). The upper cavity of the trunk of the body, containing the lungs, heart, etc. ; the chest. Thy'roid (Gr. thureos, a shield, and eidos, form). The largest of the cartilages of the larynx : the pro- jection in the front of the neck is called " Adam's apple." Tis'sue. Any substance or tex- ture ill the body formed of vari- ous elements, such as cells, fibres, blood-vessels, etc., interwoven with each other. To-bac'co (Indian, tabaco, the tube, or pipe, in which the Indians smoked the plant). A plant used for smoking and chewing, and in snuff. It has a strong smell and a pungent taste. Tra'che-a (Gr. trachus, rough). The windpipe, or the largest of the air-passages.- Trans-fu'sion (L. transfun'do, to pour from one vessel to an- , other). The operation of inject- ing blood taken from one person into the veins of another : other GLOSSARY 403 fluids than blood are sometimes used. Trich-i'na Spi-ra'lis. (A twisted hair). A minute species of para- site, or worm, which infests the flesh of the hog: may be intro- duced into the human system by eating pork not thoroughly cooked. Tym'pa-num (Gr. tumpanon, a drum). The cavity of tlie middle ear, resembling a drum in being closed by two membranes. U-re'a (L. urina, urine). One of the principal constituents of the urine, secreted from the blood by the kidneys. O-re'ter (Gr. ourein, to pass water). The excretory duct of the kid- neys. U'vu-la (L. uva, a grape). The small, pendulous body attached to the back part of the palate. Var'i-cose (L. varix, a dilated vein). An unhealthily distended or enlarged vein. Vas'cu-lar (L. vasculum, a little vessel). Pertaining to, or pos- sessing blood or lymph ves.sels. Ve'nous (L. ve'na, a vein). Per- taining to, or contained within, a vein. Ven-ti-la'tion. The introduction of fresh air into a room or build- ing in such a manner as to kee;) pure the air within it i: condition. Ven'tri-cles of the Heart. The two largest cavities of the heart, situated at its apex, or point. Ver'te-bral Col'umn (L. ver'tebra, a joint). The backbone ; also called the spinal column and spine. Ves'ti-bule. A portion of the in- teripr ear, communicating with the semicircular canals and the cochlea ; so called from its fan- cied resemblance to the vestibule, or porch, of a house. Vil'li (L. vil'lus, shaggy hair). Mi- nute, thread-like projections found upon the internal surface of the small intestine, giving it a velvety appearance. Vit're-ous (L. vi'trum, glass). Having the appearance of glass; applied to the humor occupying the largest part of the cavity of the eyeball. Viv-i-sec'tion ( L. vi'vus, alive, and si'co, to cut). The practice of operating upon living animals, for the purpose of studying some physiological process. Vo'cal Cords. Two elastic bands, or ridges, situated in the larynx ; the essential parts of the organ . of voice. INDEX PAGE PAGE Atdomen . . . . 9,22 Alcohol, Effect of, upon blood . 140 Absorption . . . 106 Effect of, in hardship . . 160 by blood-vessels . 109 Effect of, upon the skin . . 176 by the lacteals . 107 Effect of, upon special senses 233 J.ccidents ... 249 ,252 Effect of, upon throat and voice, 247 Alcohol in . . 266 Effect of, upon Icidneys 240 Achilles, Tendon of 32 Indigestion due to . . . 118 Acids, Poison from 271 Inherited craving for . . 200 Adam's apple . 144 ,245 Alcoholic liquors and nervous sys Air, Atmospheric .... 148 tem .98 Changes in, from breathing .48 Alcoholic appetite .... 86 Carbonic acid in . . 150 Alcoholic liquors, a costly vice 91 Impurities in . . . . . 151 Alcoholic liquor. Final result of 199 renovation by ventilation . . 152 Alexis St. Martin . . . 118 Air-cells of the lungs 146 Alimentary canal 92 Air-passages . 144 Anatomy delined 4 Air-passages, how protected 144 Animal life . I Albumens . . ... 72 Animal heat 156 Albuminoid substances 72 how produced 156 Alcohol 83 how regulated . . 157 as a poison . . 84, 85 and alcohol . 158 in accidents and emergencies 266 Ankle-bones . . 32 how it gets into the blood . . 139 Apparatus defined . . 5 and bodily heat . . . 158 Appetizers . . 74 Effect of, on bones . . 40 Aqueous humor . . 226 Effect of, on muscular strength 54 Arteries . . . T26, i-ii Effect of, on physical exercise 55 Artificial drinks . . 78 Fatty decay due to . . . 53 Arytenoid cartilage 245 Effect of, upon nervous system. 197 Asphyxia 252 Effect of, on digestion . . 118 Auditory canal 216 Effect of, on muscles . . 53 Auricles of the heart 129 Effect of, \ipon the circulation. •38 Backbone . . 23 Effect of, upon the heart . . 140 Baths, how and when to take them, 171 Effect of, upon the lungs . .58 Beer . 89 Effect of, upon liver . . 120 Bile . 104 40s 4o6 INDEX PAGE Bile, Uses of 105 Bladder, Gall . 105 Bleeding 263 Bleeding, how stopped . . . 263 Bleeding from stomach and lungs . 265 Blood 12, 122 Circulation of . . . 126, 134 Coagulation of . . . 125 corpuscles, Red . 123 corpuscles. White . 125 Total quantity of . .123 Blood, Uses of the ... . . 122 Blood-vessels connected with heart 131 Body, minute structure of . .7 General build of . . . 8 compared to locomotive . 2 and its nervous system . 2 Elements in the . . . . 8 Bony levers of the .... 48 Wear and tear of . . , 72 Bone, how made up . 14 General structure of . 15 Minute structure of . . 16 Resistance of, to decay . 16 Bones, Hints about health of 38 Broken . . . - 257 how joined . . 35 Effect of alcohol and tobacco on, 40 how tied together . . . 37 Repair of . . .... 34 Uses of . . 33 Different shapes of . .16 Bony Framework . . 13 Bowels, Care of the . 115 Brain . 181 Principal masses of ... 181 Breathing 142 Act of 148 Breathe, How we , -147 Why we . . . 142 Bronchial tubes . . 144 Bronchi .... 144 PAGE Bruises, how treated . 266 Burns .... 259 Capillaries . 133 Carbonic acid 152 exhaled from the lungs . . 152 in the air "53 Cardiac orifice 102 Carpal bones • 29 Cartilage 245 Arytenoid . . • 245 Cricoid . . 245 Thyroid • 245 Cells . 7 Cement of teeth . . . 94 Cerebellum 183 Cerebrum . . i5i Chest ... 22 Chewing of the food 93 Chloral ... . 208 Chocolate 79 Chyle . 106 Chyme . 104 Cider . 87 Cilia . . Circulation, General Plan of M5 126 of the blood . 134 . 137 135 I ^r Rapidity of . through the heart through the lungs Clavicle . •03 28 Clot .... Clothing, Why we need 125 173 Hints on use of Coagulation of the bloorl '74 Coccyx 125 Cocoa 24 Coffee . . . 79 Effects of 79 80 Constipation . Collar-bone . . "5 28 Color-blindness Column, Spinal .... ■ 230 H INDEX 407' ■44; Conjunctiva .... Contraction of muscles Convulsions . . . Cooking food .... Cords, Vocal .... Cornea .... Corpuscles, Blood . . Cranial nerves . . Cranium, Bones in . Cricoid cartilage Crystalline lens . , . Cuticle Cutis Decay, a law of Nature Cause of ... . Decussation of motor and sensory fibres of spinal cord Dentine Development, Physical, Importance of Diaphragm .... Movements of the, in respira- tion Diet, Different articles of Digestion General plan of . Gastric .... Intestinal . . . Disinfectants, what to use How to use . Disinfection . Distillation . . . Distilted liquors Drinks, Artificial Fermented Drowning . . Duct, Biliary . . . . Pancreatic . . . Tear . . Thoracic . . . Duodenum ... Dura Mater 229 45 252 116 ,247 223 123 184 19 245 225 161 161 81 82 24 62 9.23 149 75 I, 92 92 102 104 275 276 274 90 90 78 II 253 104 104 230 107 104 183 Ear Outer . . . Inner . . . Middle . . Care of the Bones of the Elements in the body Emergencies . . ... Emulsion of fats in digestion Enamel of the teeth . . Epiglottis Epileptic fits Ethmoid bone . . . Eustachian tube . . Excretion Organs of Exercise, Physical, effect of Amount of . . . Different kinds of Physical, in schools . in school education . . Time for .... why we need it . . , Experiments, Practical . . Why we should make . Importance of making . General Plan of making on bones . on skeleton . . with muscles . on food and drink on digestion on heart and the circulation on lungs and breathing . . on the skin ... on the nervous system . . on special senses .... on throat and voice . . . on matters of every-day health Expiration . . Movements of Extra foods . . PAGE . 216 . 216 . 218 . 216 . 220 216 8 249, 252 104 94 99.144 252 20 217 '2, gS, 235 237 57 58 59 1,61 62 59 56 280 280 280 281 285 282 291 303 310 3'4 3'6 317 320 325 327 148 150 74 4o8 INDEX PAGE PAGE Eye . . 222 Foreign bodies in ear . 261 Muscles of . . 229 Framework, Bony '3 Coats of the .... . 223 Frontal bone . . 20 Inside of the . . . . 224 Frost-bite 259 Eye, Care of the . . 232 Function defined . 6 Eyebrows ... . . 229 Gall-bladder . 104 Eyelashes . . . . . 229 Gastric juice . . 102 . 229 Action of . . 102 Face, Bones in the . 20 Gland, Thymus 109 Fainting ... 252 Thyroid . 109 Far-sight . ... 232 Glands . 92, 98 Fats 74 Oil . 167 Fermentation 82 Salivary . . 97 Ferments . 83 Sweat . . 168 Femur . . 3' Parotid . ... 97 Fibres ... 7 Submaxillary . 9; Fibrine of the blood 125 Sublingual 9: Fibula ... 31 Lymphatic . .106 ■■^c Fontanelles . . 21 Glottis . 144 Fomentations . . 251 Gullet . . lOI Food .... II Gymnastics, Various systems of 63 why we need it . . 71 Swedish system of . 63 Vegetable . . 75 German system of . 66 Animal . 75 System needed .... 67 Mineral . . . . 76 Gymnasium, Modern. Benefits from 66 how it is swallowed 99 Hair . . . '65 how much to eat III Hand, The 29 what to eat . . . 112 Hand and foot compared . 33 Proper Cooking of 116 Head ... 17 ■ "3 Bones of, how joined 22 how to eat . . . 114 Health and strength contrasted . 58 Foods, Classes of . 72 Hearing, Sense of 214 Nitrogenous 72 Heart . . 127 Mineral 74 Beating of the . '37 Extra . 74 Blood-vessels connected with . 131 Fatty . . 74 Effect of tobacco upon 141 Starchy . . 73 Circulation through the '34 Foot'. . . . 32 Sounds of the . '37 Foot and hand compared 33 Valves of the . ... 129 Foreign bodies in throat 260 Work done by tlie , . 129 in nose . 260 Heat, Bodily . 156 Foreign bodies in eye . . . 261 Heat and alcohol . . . 15S INDEX 409 Heatstroke . . 256 Humerus 29 Hemorrhage 263 Hips 27 Humor, Aqueous 226 Crystalline lens .... 225 Vitreous . . . 226 Hygiene defined . . . 4 Hyoid bone . . ■ ^7 Ice-water 79 Injured person, How to carry . 257 Inorganic foods 74 Inspiration ... .... 148 Movements of ... . . X49 Intestinal digestion 104 juice , . 105 Intestine, Large .... no Small 104 Intestines ... , . 104 Villi of the . .... 107 Iris .... . . . . 224 Jaw-bone, Upper . 21 Lower 21 Joint between skull and spine . 26 between bones of the head . . 22 Joints .... ■ • • • 35 Kinds of 35 Juice, Gastric 102 Intestinal 105 Pancreatic 105 Kidneys 237 Health of . . 239 Effect of alcohol upon . . . 240 Knee-pan 31 Lachrymal bone 21 Lacteals 106 Absorption by . . . . 107 Larynx 144, 246 Lens, Crystalline 225 Levers, Bony, of the body ... 48 Classes of, in the body ... 49 ligaments 37 PAGE 3° 14 104 Limbs, Upper Lower , . Lime in the bones . . Liver . .... Effects of alcohol upon . . 120 Locomotive, Eody compared to . 2 Lungs . . . . . . 145 Structure of 145 Lungs, Effect of alcohol upon . . 158 Lymph . 109 Lymphatic vessels . . . . 106,109 Malar bone .... 21 Marrow of the bones . . . , 15 Mastication .... . . 94 Medulla oblongata ... . 184 Metacarpal bo^es ... • ^9 Metatarsal bones . ■ ■ 33 Mineral foods .... 74 Mouth 94 Muscles 1 1| 42 Structure of 42 how they act 43 Kinds of . . . . . 45 Arrangement of .... 45 Important .... -5° Effect of alcohol on . 53 Effect of tobacco on ... . 55 Origin of 45 Insertion of 45 Muscular strength. Effect of alco- hol on 54 Nails 166 Care of the 167 Narcotics 197 Narcotics and other drugs . . 209 Nasal bone .... .21 Near-sight ... . . 231 Nerve, Auditory . 219 Optic . . . 229 Nerves 180 Cranial 184 Spinal 188 4IO INDEX Nerves, sensory, Function* of the . PAGE 189 Poisons, their antidotes . . PAGH : 270 motor, Function of the . . 189 Poisons, Narcotic .... 86, 273 Sympathetic system of . 190 Poisons, Different kinds of . . 271 Nerve tissue 180 Acid • 271 Nervous system . ... 12 177 Metallic 272 and the body 2 Other - 274 compared to telegraph system 178 Poultices 249 Two distinct parts of . . 179 Pulmonary veins •3' Health of the . . 191 artery . ^ . 131 Abuse of the . . 193 Pulse ■ 138 Effect of alcohol upon . . . 197 Pupil of eye 224 Effect of alcoholic liquors upon 198 Pylorus . 102 Final result of alcohol upon igg Questions, Test, for review . • 331 Effect of inherited, craving for Radius • 29 alcohol 200 Reflex action . . . 186 and alcoholic excess .* 200 Importance of ,87 Nitrogenous foods 72 Respiration . 12, 151 Nose, Foreign bodies in . 260 Change of air in . ■ 151 Nostrils 144 Movements of . . . • 151 Occipital bone , . 20 Object of . • 143 Oils and fats . ... 74 Organs of 144. '45 Oil-glands 167 Retina . . . 224 Opium 205 Ribs 2C Practical hints about 207 Movements of, in respiration . 149 Organ defined ... 5 True, false, floating . . 26 Organs, vital . ... 6 Sacrum 24 Palate bones 21 Saliva 96 Palpitation of the heart . . '37 Mixing food with 96 Pancreas ... 103 SaUvary glands . . 97 Pancreatic juice 105 Salt, Value of . . 77 Papillffi .... 213 Scapula 28 Parietal bones . , . . 20 Schoolrooms, Ventilation of • '55 Patella 31 Secretion . . . . 98 Pelvis . . . 27 Sensation . 210 Pepsin .... 102 Sense of hearing . 214 Periosteum 16 of sight . 222 Peristaltic action of the stomach 45 , 102 of smell . 214 212 Perspiration, Uses of . 157 of taste . . . Phalanges 30, 33 of touch . . 212 Pharynx gg ,244 Sense, Muscular . . 211 Physiology defined 4 Senses, Special . . . . . 211 Pleura 146 Serum . . 125 INDEX 411 .Sick-room, Hints for . Sight, Sense of . . . Slieleton . . . Review analysis of Skin Scarf True Absorption from the Care of the . . . Effect of alcohol upon Skull Skull and spine, how joined Sleep, Necessity for . . , amount required . . Smell, Sense of . . . Special senses .... Speech, Organ, of . . . Sphenoid bone . . . Spinal cord .... Decussation of the . Spinal nerves . ... Spine ... ... Spleen Starches and sugars . . their change into sugar Sternum . . . Stomach Digestion .... Effects of alcohol upon Walls of . . Study, General plan of . . Suffocation .... Sugars ... . . Sunstroke .... Sutures Sweat-glands ... . . Sympathetic system of nerves System defined ... Tarsal bones ... Taste, Organ of . . . Taste, Sense of ... . Tea PAGB 267 222 13. '8 41 161 161 162 164 169 176 19 26 199 196 214 12, 211 245 23 109 73 99 26 101 loi 118 102 • 73 . 256 • 19. 22 . . 168 180, 190 • • 5 ■ 32 . 212 . 212 79 Tea, Effect of 80 Tear-duct 230 Tears . ... 230 Teeth . . . . 94 Temporary set of . 95 Permanent set of . ... 95 Bicuspids . -. . . 96 Canine 96 Incisor 96 Molar 96 Wisdom 96 Care of . . 117 Temperature of the body , . . 156 of our living rooms . 157 Temporal bones ... 20 Tendon of Achilles ... 32 Tendons .... . 47 Thoracic duct . . . 108 Thorax .22 Throat .... Care of the . . Foreign bodies in Thyroid cartilage 109 Tibia .... Tissues defined . Tobacco Effect of, upon bones . Effect of, upon muscles Effect of, upon digestion Effect of, upon heart Effect of, upon skin . . Effect of, upon throat and voice .... . . 247 Effect of, from moral point of view . . Evil effects of '2,243 244 . 260 31 6 201 40 53 121 141 176 Tongue .... Touch, Sense of . Trachea . . . Trunk . . . Bones in the Turbinated bones 204 203 212 212 144 22 412 INDEX TyiTipanum of the ear . 216 Membrane of . . 219 Ulna . . 29 Urine . . ■ ■ 239 Valves of the heart . 129 of the veins . 132 Valves, Tricuspid 130 Mitral . 130 Semilunar 130 Veins . . . . 126, 132 Veins compared to a sewer system 127; 133 Valves of . . . .132 Ventilation . 154 of schoolrooms .... 155 Ventricles of the heart 129 Vertebrae .... . 23 Villi of the intestines . . 107 Absorption by 107 PAGB 226 . 226 144, 247 12, 247 Vision, Mechanism of Vitreous humor Vocal cords . . . . Voice . . Effect of alcohol and tobacco upon . . .... 248 Organ of . . , 246 Quality of . . 247 Vomer . 21 Warm, Why the body is . . -156 Waste matters, Getting rid of . 235 Principal . . 235 Water 76 Wear and tear , . -72 Windpipe . ... 144 Wine . . . .88 Work, waste, and repair . . 70 Wounds, cut and torn ... . 266 Wrist, . . 30 BLAISDELL'S REVISED SERIES OF PHYSIOLOGIES BY DR. ALBERT F. BLAISDELL Author of " First Steps with American and British Authors," " Storieb of the Civil War," •' Study of the English Classics," " Readings from the Waverley Novels," '* Stories from English History," etc. COMPRISING Physiology for Little Folks (Revised Edition of " Child's Book of Health ") Introduction Price, 30 cents net Exchange Price, 16 cents and the book displaced Physiology for Boys and Girls (Revised Edition of " How to Keep Well ") Introduction Price, 42 cents, net Exchange Price, 23 cents and the book displaced Young- Folks' Physiology {Revised Ediiion of " Our Bodies ") Introduction Price, 60 cents, net Exchange Price, 35 cents and the book displaced The leading purpose of the books of this series is to treat of the care and preser- vation of tlie health. The latest fiicts are given; and in each division the effects of alcoholic drinks, stimulants, and narcotics on the human system are shown with force, accuracy, and candor. The autlior, who is a successful practising physician, and largely engaged in educational matters, has accomplislied the difficult task of adapting the. different books of the series to the capacity and taste of the different grades of pupils for whom they are designed, the language employed being remark- ably adapted to each grade. Many experiments with and without apparatus are suggested and explained in a manner that will be invaluable to the pupils. The health notes, in the form of blackboard exercises, in the " Physiology for Little Folks," in physical exercises, in ** Young Folks' Physiology," and m hundreds of suggestions throughout the volumes, form especially good features of the series. As suggested by the general title the volumes have been thoroughly revised, and are printed from entirely new plates, with many new illustrations. These new editions have been prepared under the advice and supervision of Mrs. Maky H. Hunt, National and International Superintendent of the Scientific Department of the Women's Christian Temperance Union. Blaisdell's Physiologies are in use in Ifoston, New York, Philadelphia, Providence, Springfield, Augusta, Me., and hundreds of cities and towns throughout the country. Sample copies for examination sent free on receipt of above prices Special terms for introduction and exchange E- • THE , . nEOGRAPHlCAL IGIURL8QUE*U*.» Readers In Four Fully Illustrated Volumes By CHAS. F. KING Master Dearborn Grammar School, Boston ; President National Summer School, Saratoga Springs; Autlior of " Methods and Aids in Geography First Book: HOME AND SCHOOL. 240 pages. Over 12S niastrations. Frlce, 60 cents net. By mall, 66 cents. Second Book: THIS CONTINENT OF OURS. 320 pages. Fully Illustrated, Frlce, 72 cents net. By mail, 83 cents. Sight takes the lead as a chantul of perception. — Spencer. Third Book: THE LAND WE LIVE IN. 240 pages. 163 niustrations. Price, 66 centa net. 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T Properly graded for the different classes in grammar schools. 8 Containing a vast amount of information for old and young, for teacher and taught. 9 A happy combination of the useful and interesting. 10 From these readers can be easily taught Geography, Reading, SpeUing Dictation, and Composition. 11 All mere map explanations and descriptions carefully avoided. 12 Costly in preparation, but cheap in price. 13 These books can be used in place of, or in connection with, geographies. 14 These fascinatijig^ geographical readers will take the place of the stupid sets of map questions and columns of statistics. LEE AND SHEPARD Pnlilisliers 10 II Street BOSTON /, ' ^. -•// y ^^„ ^<-""' .^'i5.