Chapter 20

Experimental Work in Physiology.

406. The Limitations of Experimental Work in Physiology in Schools. Unlike other branches of science taught in the schools from the experimental point of view, the study of physiology has its limitations. The scope and range of such experiments is necessarily extremely limited compared with what may be done with the costly and elaborate apparatus of the medical laboratory. Again, the foundation of physiology rests upon systematic and painstaking dissection of the dead human body and the lower animals, which mode of study very properly is not permitted in ordinary school work. Experiments upon the living human body and the lower animals, now so generally depended upon in our medical and more advanced scientific schools, for obvious reasons can be performed only in a crude and quite superficial manner in secondary schools.

Hence in the study of physiology in schools many things must be taken for granted. The observation and experience of medical men, and the experiments of the physiologist in his laboratory must be depended upon for data which cannot be well obtained at first hand by young students.

407. Value of Experiments in Physiology in Secondary Schools. While circumstances and regard for certain proprieties of social life forbid the use of a range of experiments, in anatomy and physiology, such as are permitted in other branches of science in secondary schools, it by no means follows that we are shut out altogether from this most important and interesting part of the study. However simple and crude the apparatus, the skillful and enthusiastic teacher has at his command a wide series of materials which can be profitably utilized for experimental instruction. As every experienced teacher knows, pupils gain a far better knowledge, and keep up a livelier interest in any branch of science, if they see with their own eyes and do with their own hands that which serves to illuminate and illustrate the subject-matter.

Note. For additional suggestions and practical helps on the subject of experimental work in physiology the reader is referred to Blaisdell’s _How to Teach Physiology_, a handbook for teachers. A copy of this pamphlet will be sent postpaid to any address by the publishers of this book on receipt of ten cents.

The experimental method of instruction rivets the attention and arouses and keeps alive the interest of the young student; in fact, it is the only true method of cultivating a scientific habit of study[57]. The subject-matter as set forth on the printed pages of this book should be mastered, of course, but at the same time the topics discussed should be illuminated and made more interesting and practical by a well-arranged series of experiments, a goodly show of specimens, and a certain amount of microscopical work.

408. The Question of Apparatus. The author well understands from personal experience the many practical difficulties in the way of providing a suitable amount of apparatus for classroom use. If there are ample funds for this purpose, there need be no excuse or delay in providing all that is necessary from dealers in apparatus in the larger towns, from the drug store, markets, and elsewhere. In schools where both the funds and the time for such purposes are limited, the zeal and ingenuity of teachers and students are often put to a severe test. Fortunately a very little money and a great deal of ingenuity and patience will do apparent wonders towards providing a working supply of apparatus.

It will be noticed that many of the experiments in the preceding chapters of this book can be performed with very simple, and often a crude and home-made sort of apparatus. This plan has been rigidly followed by the author, first, because he fully realizes the limitations and restrictions of the subject; and secondly, because he wishes to emphasize the fact that expensive and complicated apparatus is by no means necessary to illustrate the great principles of anatomy and physiology.

409. Use of the Microscope. To do thorough and satisfactory work in physiology in our higher schools a compound microscope is almost indispensable. Inasmuch as many of our best secondary schools are equipped with one or more microscopes for use in other studies, notably botany, it is much less difficult than it was a few years ago to obtain this important help for the classes in physiology.

Illustration: Fig. 170.—A Compound Microscope

For elementary class work a moderate-priced, but well-made and strong, instrument should be provided. If the school does not own a microscope, the loan of an instrument should be obtained for at least a few weeks from some person in the neighborhood.

The appearance of the various structures and tissues of the human body as revealed by the microscope possesses a curious fascination for every observer, especially for young people. No one ever forgets the first look at a drop of blood, or the circulation of blood in a frog’s foot as shown by the microscope.

Note. For detailed suggestions in regard to the manipulation and use of the microscope the student is referred to any of the standard works on the subject. The catalogues of scientific-instrument makers of our larger cities generally furnish a list of the requisite materials or handbooks which describe the use of the various microscopes of standard make. The author is indebted to Bergen’s _Elements of Botany_ for the following information concerning the different firms which deal in microscopes. “Several of the German makers furnish excellent instruments for use in such a course as that here outlined. The author is most familar with the Leitz microscopes, which are furnished by Wm. Krafft, 411 West 59th St., New York city, or by the Franklin Educational Co., 15 and 17 Harcourt St., Boston. The Leitz Stand, No. IV., can be furnished duty free (for schools only), with objectives 1, 3, and 5, eye-pieces I. and III., for $24.50. If several instruments are being provided, it would be well to have part of them equipped with objectives 3 and 7, and eye-pieces I. and III. “The American manufacturers, Bausch & Lomb Optical Company, Rochester, N.Y., and No. 130 Fulton St., New York city, have this year produced a microscope of the Continental type which is especially designed to meet the requirements of the secondary schools for an instrument with rack and pinion coarse adjustment and serviceable fine adjustment, at a low price. They furnish this new stand, ‘AAB,’ to schools and teachers at ‘duty-free’ rates, the prices being for the stand with two eye-pieces (any desired power), ⅔-inch and ¼-inch objectives, $25.60, or with 2-inch, ⅔-inch, and ¼-inch objectives, and two eye-pieces, $29.20. Stand ‘A,’ the same stand as the ‘AAB,’ without joint and with sliding tube coarse adjustment (as in the Leitz Stand IV.), and with three eye-pieces and ⅔-inch and ¼-inch objectives, is furnished for $20.40. Stand ‘A,’ with two eye-pieces, ⅔-inch and ⅙-inch objectives, $20.40.”

410. The Use of the Skeleton and Manikin. The study of the bones by the help of a skeleton is almost a necessity. To this intent, schools of a higher grade should be provided both with a skeleton and a manikin. If the former is not owned by the school, oftentimes a loan of one can be secured of some medical man in the vicinity. Separate bones will also prove useful. In fact, there is no other way to study properly the structure and use of the bones and joints than by the bones themselves. A good manikin is also equally serviceable, although not so commonly provided for schools on account of its cost.

411. The Question of Vivisection and Dissection. There should be no question at all concerning vivisection. _In no shape or form should it be allowed in any grade of our schools._ Nor is there any need of much dissection in the grammar-school grades. A few simple dissections to be performed with fresh beef-joints, tendons of turkey legs, and so on, will never engender cruel or brutal feelings toward living things. In the lower grades a discreet teacher will rarely advise his pupils to dissect a dead cat, dog, frog, or any other animal. Instead of actual dissection, the pupils should examine specimens or certain parts previously dissected by the teacher,—as the muscles and tendons of a sheep, the heart of an ox, the eye of a codfish, and so on. Even under these restrictions the teacher should not use the knife or scissors before the class to open up any part of the specimen. In brief, avoid everything that can possibly arouse any cruel or brutal feeling on the part of young students.

In the higher schools, in normal and other training schools, different conditions prevail. Never allow vivisection in any form whatever, either in school or at home. Under the most exact restrictions students in these schools may be taught to make a few simple dissections.

Most teachers will find, however, even in schools of a higher grade, that the whole subject is fraught with many difficulties. It will not require much oftentimes to provoke in a community a deal of unjust criticism. A teacher’s good sense and discretion are often put to a severe test.

Additional Experiments.

To the somewhat extended list of experiments as described in the preceding chapters a few more are herewith presented which may be used as opportunity allows to supplement those already given.

Experiment 193. _To examine white fibrous tissue._ Snip off a very minute portion from the muscle of a rabbit, or any small animal recently dead. Tease the specimen with needles, mount in salt solution and examine under a high power. Note the course and characters of the fibers.

Experiment 194. _To examine elastic tissue._ Tease out a small piece of ligament from a rabbit’s leg in salt solution; mount in the same, and examine as before. Note the curled elastic fibers.

Experiment 195. _To examine areolar tissue._ Gently tease apart some muscular fibers, noting that they are attached to each other by connective tissue. Remove a little of this tissue to a slide and examine as before. Examine the matrix with curled elastic fiber mixed with straight white fibers.

Experiment 196. _To examine adipose tissue._ Take a bit of fat from the mesentery of a rabbit. Tease the specimen in salt solution and mount in the same. Note the fat cells lying in a vascular meshwork.

Experiment 197. _To examine connective tissues._ Take a very small portion from one of the tendons of a rabbit, or any animal recently dead; place upon a glass slide with a drop of salt solution; tease it apart with needles, cover with thin glass and examine with microscope. The fine wavy filaments will be seen. Allow a drop of dilute acetic acid to run under the cover glass; the filaments will swell and become transparent.

Experiment 198. Tease out a small piece of ligament from the rabbit’s leg in salt solution; mount in the same, and examine under a high power. Note the curled elastic fibers.

Experiment 199. _A crude experiment to represent the way in which a person’s neck is broken._ Bring the ends of the left thumb and the left second finger together in the form of a ring. Place a piece of a wooden toothpick across it from the middle of the finger to the middle of the thumb. Put the right forefinger of the other hand up through the front part to represent the odontoid process of the axis, and place some absorbent cotton through the other part to represent the spinal cord. Push backwards with the forefinger with just enough force to break the toothpick and drive its fragments on to the cotton.

Experiment 200. _To illustrate how the pulse-wave is transmitted along an artery._ Use the same apparatus as in Experiment 106, p. 201. Take several thin, narrow strips of pine wood. Make little flags by fastening a small piece of tissue paper on one end of a wooden toothpick. Wedge the other end of the toothpick into one end of the strips of pine wood. Use these strips like levers by placing them across the long rubber tube at different points. Let each lever compress the tube a little by weighting one end of it with a blackboard eraser or book of convenient size. As the pulse-wave passes along under the levers they will be successively raised, causing a slight movement of the tissue-paper flags.

Experiment 201. _The 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 that the heart is uppermost, with its apex turned toward 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 venæ cavæ_, 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 portion of the wall of the _right ventricle_ towards its lower part, so as to lay the cavity open. Gradually enlarge the opening until the _chordæ tendineæ_ 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 _pulmonary 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_.

Experiment 202. _To show the circulation in a frog’s foot_ (see Fig. 78, p. 192). 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 occasionally moistened with water. Care should be taken not to occasion any pain to the frog.

Experiment 203. _To illustrate the mechanics of respiration_[58] (see Experiment 122, p. 234). “In a large lamp-chimney, the top of which is closed by a tightly fitting perforated cork (A), is arranged a pair of rubber bags (C) which are attached to a Y connecting tube (B), to be had of any dealer in chemical apparatus or which can be made by a teacher having a bunsen burner and a little practice in the manipulation of glass (Fig. 171). From the center of the cork is attached a rubber band by means of a staple driven through the cork, the other end of which (D) is attached to the center of a disk of rubber (E) such as dentists use. This disk is held to the edge of the chimney by a wide elastic band (F). There is a string (G) also attached to the center of the rubber disk by means of which the diaphragm may be lowered. Such is a description of the essentials of the model. The difficulties encountered in its construction are few and easily overcome. In the first place, the cork must be air-tight, and it is best made so by pouring a little melted paraffin over it, care being taken not to close the tube. The rubber bags were taken from toy balloon-whistles. In the construction of the diaphragm, it is to be remembered that it also must be air-tight, and in order to resemble the human diaphragm, it must have a conical appearance when at rest. In order to avoid making any holes in the rubber, the two attachments (one of the rubber band, and the other of the string) were made in this wise: the rubber was stretched over a button having an eye, then under the button was placed a smaller ring from an old umbrella; to this ring was attached the rubber band, and to the eye of the button was fastened the operating string. When not in use the diaphragm should be taken off to relieve the strain on the rubber band.”

Illustration: Fig. 171.

Experiment 204. _To illustrate the action of the intercostal muscles_ (see sec. 210). The action of the intercostal muscles is not at first easy to understand; but it will be readily comprehended by reference to a model such as that represented in Fig. 172. This maybe easily made by the student himself with four laths of wood, fastened together at the corners, A, B, C, D, with pins or small screws, so as to be movable. At the points E, F, G, H, pins are placed, to which elastic bands may be attached (A). B D represents the vertebral column; A C, the sternum; and A B and C D, the ribs. The elastic band F G represents the _external_ intercostal muscles, and E H, the _internal_ intercostals. If now the elastic band E H be removed, the remaining band, F G, will tend to bring the two points to which it is attached, nearer together, and the result will be that the bars A B and C D will be drawn upwards (B), that is, in the same direction as the ribs in the act of _inspiration_. When the elastic band E H is allowed to exert its force, the opposite effect will be produced (C); in this case representing the position of the ribs in an act of _expiration_.

Illustration: Fig. 172.

Experiment 205. Pin a round piece of bright red paper (large as a dinner-plate) to a white wall, with a single pin. Fasten a long piece of thread to it, so it can be pulled down in a moment. Gaze steadily at the red paper. Have it removed while looking at it intently, and a greenish spot takes its place.

Experiment 206. Lay on different parts of the skin a small, square piece of paper with a small central hole in it. Let the person close his eyes, while another person gently touches the uncovered piece of skin with cotton wool, or brings near it a hot body. In each case ask the observed person to distinguish between them. He will always succeed on the volar side of the hand, but occasionally fail on the dorsal surface of the hand, the extensor surface of the arm, and very frequently on the skin of the back.

Experiment 207. _Wheatstone’s fluttering hearts_. Make a drawing of a red heart on a bright blue ground. In a dark room lighted by a candle hold the picture below the level of the eyes and give it a gentle to-and-fro motion. On continuing to look at the heart it will appear to move or flutter over the blue background.

Experiment 208. At a distance of six inches from the eyes hold a veil or thin gauze in front of some printed matter placed at a distance of about two feet. Close one eye, and with the other we soon see either the letters distinctly or the fine threads of the veil, but we cannot see both equally distinct at the same time. The eye, therefore, can form a distinct image of a near or distant object, but not of both at the same time; hence the necessity for accommodation.

Experiment 209. Place a person in front of a bright light opposite a window, and let him look at the light; or place one’s self opposite a well-illuminated mirror. Close one eye with the hand and observe the diameter of the other pupil. Then suddenly remove the hand from the closed eye: light falls upon it; at the same time the pupil of the other eye contracts.

Experiment 210. _To illustrate the blind spot. Marriott’s experiment_. On a white card make a cross and a large dot, either black or colored. Hold the card vertically about ten inches from the right eye, the left being closed. Look steadily at the cross with the right eye, when both the cross and the circle will be seen. Gradually approach the card toward the eye, keeping the axis of vision fixed on the cross. At a certain distance the circle will disappear, _i.e._, when its image falls on the entrance of the optic nerve. On bringing the card nearer, the circle reappears, the cross, of course, being visible all the time (see Experiment 180, p. 355).

Experiment 211. _To map out the field of vision_. A crude method is to place the person with his back to a window, ask him to close one eye, stand in front of him about two feet distant, hold up the forefingers of both hands in front of and in the plane of your own face. Ask the person to look steadily at your nose, and as he does so observe to what extent the fingers can be separated horizontally, vertically, and in oblique directions before they disappear from his field of vision.

Experiment 212. _To illustrate imperfect judgment of distance_. Close one eye and hold the left forefinger vertically in front of the other eye, at arm’s length, and try to strike it with the right forefinger. On the first trial one will probably fall short of the mark, and fail to touch it. Close one eye, and rapidly try to dip a pen into an inkstand, or put a finger into the mouth of a bottle placed at a convenient distance. In both cases one will not succeed at first. In these cases one loses the impressions produced by the convergence of the optic axes, which are important factors in judging of distance.

Experiment 213. Hold a pencil vertically about twelve inches from the nose, fix it with both eyes, close the left eye, and then hold the right index finger vertically, so as to cover the lower part of the pencil. With a sudden move, try to strike the pencil with the finger. In every case one misses the pencil and sweeps to the right of it.

Experiment 214. _To illustrate imperfect judgment of direction_. As the retina is spherical, a line beyond a certain length when looked at always shows an appreciable curvature. Hold a straight edge just below the level of the eyes. Its upper margin shows a slight concavity.

Surface Anatomy and Landmarks.

In all of our leading medical colleges the students are carefully and thoroughly drilled on a study of certain persons selected as models. The object is to master by observation and manipulation the details of what is known as surface anatomy and landmarks. Now while detailed work of this kind is not necessary in secondary schools, yet a limited amount of study along these lines is deeply interesting and profitable. The habit of looking at the living body with anatomical eyes and with eyes at our fingers’ ends, during the course in physiology, cannot be too highly estimated.

In elementary work it is only fair to state that many points of surface anatomy and many of the landmarks cannot always be defined or located with precision. A great deal in this direction can, however, be done in higher schools with ingenuity, patience, and a due regard for the feelings of all concerned. Students should be taught to examine their own bodies for this purpose. Two friends may thus work together, each serving as a “model” to the other.

To the following syllabus may be added such other similar exercises as ingenuity may suggest or time permit.

Syllabus.

I. Bony Landmarks.

1. The _occipital protuberance_ can be distinctly felt at the back of the head. This is always the thickest part (often three-quarters of an inch or more) of the skull-cap, and is more prominent in some than in others. The thinnest part is over the temples, where it may be almost as thin as parchment.

2. The working of the _condyle of the lower jaw_ vertically and from side to side can be distinctly felt and seen in front of the ear. When the mouth is opened wide, the condyle advances out of the glenoid cavity, and returns to its socket when the mouth is shut. In front of the ear, lies the zygoma, one of the most marked and important landmarks to the touch, and in lean persons to the eye.

3. The sliding movement of the _scapula_ on the chest can be properly understood only on the living subject. It can move not only upwards and downwards, as in shrugging the shoulders, backwards and forwards, as in throwing back the shoulders, but it has a rotary movement round a movable center. This rotation is seen while the arm is being raised from the horizontal to the vertical position, and is effected by the cooperation of the trapezius with the serratus magnus muscles.

4. The _patella_, or knee-pan, the _two condyles of the tibia_, the _tubercle on the tibia_ for the attachment of the ligament of the patella, and the _head of the fibula_ are the chief bony landmarks of the knee. The head of the fibula lies at the outer and back part of the tibia. In extension of the knee, the patella is nearly all above the condyles. The inner border of the patella is thicker and more prominent than the outer, which slopes down toward its condyle.

5. The short, front edge of the _tibia_, called the “shin,” and the broad, flat, subcutaneous surface of the bone can be felt all the way down. The inner edge can be felt, but not so plainly.

6. The head of the _fibula_ is a good landmark on the outer side of the leg, about one inch below the top of the tibia. Note that it is placed well back, and that it forms no part of the knee joint, and takes no share in supporting the weight. The shaft of the fibula arches backwards and is buried deep among the muscles, except at the lower fourth, which can be distinctly felt.

7. The _malleoli_ form the great landmarks of the ankle. The outer malleolus descends lower than the inner. The inner malleolus advances more to the front and does not descend so low as the outer.

8. The line of the _clavicle_, or collar bone, and the projection of the joint at either end of it can always be felt. Its direction is not perfectly horizontal, but slightly inclined downwards. We can distinctly feel the _spine_ of the scapula and its highest point, the _acromion_.

9. Projecting beyond the acromion (the arm hanging by the side), we can feel, through the fibers of the _deltoid_, the upper part of the humerus. It distinctly moves under the hand when the arm is rotated. It is not the head of the bone which is felt, but its prominences (the tuberosities). The greater, externally; the lesser in front.

10. The _tuberosities of the humerus_ form the convexity of the shoulder. When the arm is raised, the convexity disappears,—there is a slight depression in its place. The head of the bone can be felt by pressing the fingers high up in the axilla.

11. The _humerus_ ends at the elbow in two bony prominences (internal and external condyles). The internal is more prominent. We can always feel the _olecranon_. Between this bony projection of the ulna and the internal condyle is a deep depression along which runs the ulna nerve (commonly called the “funny” or “crazy” bone).

12. Turn the hand over with the palm upwards, and the edge of the _ulna_ can be felt from the olecranon to the prominent knob (styloid process) at the wrist. Turn the forearm over with the palm down, and the head of the ulna can be plainly felt and seen projecting at the back of the wrist.

13. The upper half of the _radius_ cannot be felt because it is so covered by muscles; the lower half is more accessible to the touch.

14. The three rows of projections called the “knuckles” are formed by the proximal bones of the several joints. Thus the first row is formed by the ends of the metacarpals, the second by the ends of the first phalanges, and the third by the ends of the second phalanges. That is, in all cases the line of the joints is a little in advance of the knuckles and nearer the ends of the fingers.

II. Muscular Landmarks.

1. The position of the _sterno-mastoid_ muscle as an important and interesting landmark of the neck has already been described (p. 70).

2. If the left arm be raised to a vertical position and dropped to a horizontal, somewhat vigorously, the tapering ends of the _pectoralis major_ and the tendons of the _biceps_ and _deltoid_ may be felt by pressing the parts in the axilla between the fingers and thumb of the right hand.

3. The appearance of the _biceps_ as a landmark of the arm has already been described (p. 70). The action of its antagonist, the _triceps_, may be studied in the same manner.

4. The _sartorius_ is one of the fleshy landmarks of the thigh, as the biceps is of the arm, and the sterno-cleido-mastoid of the neck. Its direction and borders may be easily traced by raising the leg,—a movement which puts the muscle in action.

5. If the model be directed to stand on tiptoe, both of the large muscles of the calf, the _gastrocnemius_ and _soleus_, can be distinguished.

6. Direct the model, while sitting upright, to cross one leg over the other, using his utmost strength. The great muscles of the inner thigh are fully contracted. Note the force required to pull the legs to the ordinary position.

7. With the model lying in a horizontal position with both legs firmly held together, note the force required to pull the feet apart while the great muscles of the thigh are fully contracted.

8. In forcible and resisted flexion of the wrist two tendons come up in relief. On the outer side of one we feel the pulse at the wrist, the radial artery here lying close to the radius.

9. On the outer side of the wrist we can distinctly see and feel when in action, the three extensor tendons of the thumbs. Between two of them is a deep depression at the base of the thumb, which the French call the “anatomical tobacco box.”

10. The relative position of the several extensor tendons on the back of the wrist and fingers as they play in their grooves over the back of the radius and ulna can be distinctly traced when the several muscles are put in action.

11. There are several strong tendons to be seen and felt about the ankle. Behind is the _tendo Achillis_. It forms a high relief with a shallow depression on each side of it. Behind both the inner and outer ankle several tendons can be felt. Over the front of the ankle, when the muscles are in action, we can see and feel several tendons. They start up like cords when the action is resisted. They are kept in their proper relative position by strong pulleys formed by the annular ligament. Most of these tendons can be best seen by stand a model on one foot, _i.e._ in unstable equilibrium.

III. Landmarks of the Heart.

To have a general idea of the form and position of the _heart_, map its outline with colored pencils or crayon on the chest wall itself, or on some piece of clean, white cloth, tightly pinned over the clothing. A pattern of the heart may be cut out of pasteboard, painted red, or papered with red paper, and pinned in position outside the clothing. The apex of the heart is at a point about two inches below the left nipple and one inch to its sternal side. This point will be between the fifth and sixth ribs, and can generally be determined by feeling the apex beat.

IV. Landmarks of a Few Arteries.

The pulsation of the _temporal_ artery can be felt in front of the ear, between the zygoma and the ear. The _facial_ artery can be distinctly felt as it passes over the upper jaw at the front edge of the masseter muscle. The pulse of a sleeping child can often be counted at the anterior fontanelle by the eye alone.

About one inch above the clavicle, near the outer border of the sterno-mastoid, we can feel the pulsation of the great _subclavian_ artery. At the back of the knee the _popliteal_ artery can be felt beating. The _dorsal_ artery of the foot can be felt beating on a line from the middle of the ankle to the interval between the first and second metatarsal bones.

When the arm is raised to a right angle with the body, the _axillary_ artery can be plainly felt beating in the axilla. Extend the arm with palm upwards and the _brachial_ artery can be felt close to the inner side of the biceps. The position of the _radial_ artery is described in Experiment 102.

Glossary.

Abdomen (Lat. _abdo_, _abdere_, to conceal). The largest cavity of the body, containing the liver, stomach, intestines, and other organs.

Abductor (Lat. _abduco_, to draw from). A muscle which draws a limb from the middle line of the body, or a finger or toe from the middle line of the foot or hand.

Absorbents (Lat. _absorbere_, to suck up). The vessels which take part in the process of absorption.

Absorption. The process of sucking up nutritive or waste matters by the blood-vessels or lymphatics.

Accommodation of the Eye. The alteration in the shape of the crystalline lens, which accommodates, or adjusts, the eye for near or remote vision.

Acetabulum (Lat. _acetabulum_, a small vinegar-cup). The cup-shaped cavity of the innominate bone for receiving the head of the femur.

Acid (Lat. _acidus_, from _acere_, to be sour). A substance usually sour, sharp, or biting to the taste.

Acromion (Gr. ἀκρον the tip, and ᾧμος, the shoulder). The part of the scapula forming the tip of the shoulder.

Adam’s Apple. An angular projection of cartilage in the front of the neck. It may be particularly prominent in men.

Adductor (Lat. _adduco_, to draw to). A muscle which draws towards the middle line of the body, or of the hand or foot.

Adenoid (Gr. ἀδήν, a gland). Tissue resembling gland tissue.

Afferent (Lat. _ad_, to, and _fero_, to convey). Vessels or nerves carrying the contents or impulses from the periphery to the center.

Albumen, or Albumin (Lat. _albus_, white). An animal substance resembling the white of an egg.

Albuminuria. A combination of the words “albumin” and “urine.” Presence of _albumen_ in the _urine_.

Aliment (Lat. _alo_, to nourish). That which affords nourishment; food.

Alimentary (Lat. _alimentum_, food). Pertaining to _aliment_, or food.

Alimentary Canal (Lat. _alimentum_). The tube in which the food is digested or prepared for reception into the blood.

Alkali (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.

Alveolar (Lat. _alveolus_, a little hollow). Pertaining to the alveoli, the _cavities_ for the reception of the teeth.

Amœba (Gr. ἀμείβω, to change). A single-celled, protoplasmic organism, which is constantly changing its form by protrusions and withdrawals of its substance.

Amœboid. Like an _amœba_.

Ampulla (Lat. _ampulla_, a wine-flask). The dilated part of the semicircular canals of the internal ear.

Anabolism (Gr. ἀναβάλλω, to throw or build up). The process by means of which simpler elements are _built up_ into more complex.

Anæsthetics (Gr. ἀν, without, and αἰσθησία, feeling). Those medicinal agents which prevent the feeling of pain, such as chloroform, ether, laughing-gas, etc.

Anastomosis (Gr. ἀνά, by, and στόμα, a mouth). The intercommunication of vessels.

Anatomy (Gr. ἀνατέμνω, to cut up). The science which describes the structure of living things. The word literally means dissection.

Antiseptic (Lat. _anti_, against, and _sepsis_, poison). Opposing or counter-acting putrefaction.

Antrum (Lat. _antrum_, a cave). The cavity in the upper jaw.

Aorta (Gr. ἀορτή, from ἀείρο, to raise up). The great artery that _rises up_ from the left ventricle of the heart.

Aponeurosis (Gr. ἀπό, from, and νεῦρον, a nerve). A fibrous membranous expansion of a tendon; the nerves and tendons were formerly thought to be identical structures, both appearing as white cords.

Apoplexy (Gr. ἀποπληξία, a sudden stroke). The escape of blood from a ruptured blood-vessel into the substance of the brain.

Apparatus. A number of organs of various sizes and structures working together for some special object.

Appendages (Lat. _ad_ and _pendeo_, to hang from). Something connected with a part.

Aqueous Humor (Lat. _aqua_, water). The watery fluid occupying the space between the cornea and crystalline lens of the eye.

Arachnoid Membrane (Gr. ἀράχνη, a spider, and εἰδώς, like). The thin covering of the brain and spinal cord, between the dura mater and the pia mater.

Arbor Vitæ. Literally, “the tree of life”; a name given to the peculiar appearance presented by a section of the cerebellum.

Areolar (Lat. _areola_, a small space, dim. of _area_). A term applied to a connective tissue containing _small spaces_.

Artery (Gr. ἀήρ, air, and τερέω, 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.

Articulation (Lat. _articulo_, to form a joint). The more or less movable union of bones, etc.; a joint.

Arytenoid Cartilages (Gr. ἀρύταινα, a ladle). Two small cartilages of the larynx, resembling the mouth of a pitcher.

Asphyxia (Gr. ἀ, without, and σφίξις, the pulse). Literally, “without pulse.” Condition caused by non-oxygenation of the blood.

Assimilation (Lat. _ad_, to, and _similis_, like). The conversion of food into living tissue.

Asthma (Gr. ἆσθμα, a gasping). Spasmodic affection of the bronchial tubes in which free respiration is interfered with, owing to their diminished caliber.

Astigmatism (Gr. ἀ, without, and στίγμα, a point). Irregular refraction of the eye, producing a blurred image.

Atrophy (Gr. ἀ, without, and τροφή, nourishment). Wasting of a part from lack of nutrition.

Auditory Nerve (Lat. _audio_, to hear). The special nerve of hearing.

Auricle (Lat. _auricula_, a little ear). A cavity of the heart.

Azygos (Gr. ἀ, without, and ζυγός, a yoke). Without fellow; not paired.

Bacteria (βακτήριον, a staff). A microscopic, vegetable organism; certain species are active agents in fermentation, while others appear to be the cause of infectious diseases.

Bactericide (_Bacterium_ and Lat. _caedere_, to kill). Same as _germicide_.

Bile. The gall, or peculiar secretion of the liver; a viscid, yellowish fluid, and very bitter to the taste.

Biology (Gr. βίος, life, and λόγος, discourse). The science which treats of living bodies.

Bladder (Saxon _bleddra_, a bladder, a goblet). A bag, or sac, serving as a receptacle of some secreted fluid, as the _gall bladder_, etc. The receptacle of the urine in man and other animals.

Bright’s Disease. A group of diseases of the kidney, first described by Dr. Bright, an English physician.

Bronchi (Gr. βρόγχος, windpipe). The first two divisions, or branches, of the trachea; one enters each lung.

Bronchial Tubes. The smaller branches of the trachea within the substance of the lungs terminating in the air cells.

Bronchitis. Inflammation of the larger bronchial tubes; a “cold” affecting the air passages.

Bunion. An enlargement and inflammation of the first joint of the great toe.

Bursa. A pouch; a membranous sac interposed between parts which are subject to movement, one on the other, to allow them to glide smoothly.

Callus (Lat. _calleo_, to be thick-skinned). Any excessive hardness of the skin caused by friction or pressure.

Canal (Lat. _canalis_, a canal). A tube or passage.

Capillary (Lat. _capillus_, hair). The smallest blood-vessels, so called because they are so minute.

Capsule (Lat. _capsula_, a little chest). A membranous bag enclosing a part.

Carbon Dioxid, often called _carbonic acid_. The gas which is present in the air breathed out from the lungs; a waste product of the animal kingdom and a food of the vegetable kingdom.

Cardiac (Gr. καρδία, the heart). The cardiac orifice of the stomach is the upper one, and is near the heart; hence its name.

Carnivorous (Lat. _caro_, flesh, and _voro_, to devour). Subsisting upon flesh.

Carron Oil. A mixture of equal parts of linseed oil and lime-water, so called because first used at the Carron Iron Works in Scotland.

Cartilage. A tough but flexible material forming a part of the joints, air passages, nostrils, ear; gristle, etc.

Caruncle (Lat. _caro_, flesh). The small, red, conical-shaped body at the inner angle of the eye, consisting of a cluster of follicles.

Casein (Lat. _caseus_, cheese). The albuminoid substance of milk; it forms the basis of cheese.

Catarrh. An inflammation of a mucous membrane, usually attended with an increased secretion of mucus. The word is often limited to _nasal_ catarrh.

Cauda Equina (Lat., horse’s tail). The collection of large nerves descending from the lower end of the spinal cord.

Cell (Lat. _cella_, a storeroom). The name of the tiny miscroscopic elements, which, with slender threads or fibers, make up most of the body; they were once believed to be little hollow chambers; hence the name.

Cement. The substance which forms the outer part of the fang of a tooth.

Cerebellum (dim. for _cerebrum_, the brain). The little brain, situated beneath the posterior third of the cerebrum.

Cerebrum. The brain proper, occupying the upper portion of the skull.

Ceruminous (Lat. _cerumen_, ear wax). A term applied to the glands secreting cerumen, or _ear wax_.

Chloral. A powerful drug and narcotic poison used to produce sleep.

Chloroform. A narcotic poison generally used by inhalation; of extensive use in surgical operations. It produces anæsthesia.

Chondrin (Gr. χονδρός, cartilage). A kind of gelatine obtained by boiling _cartilage_.

Chordæ Tendineæ. Tendinous cords.

Choroid (Gr. χορίον, skin, and εἶδος, form). The middle coat of the eyeball.

Chyle (Gr. χυλός, juice). The milk-like fluid formed by the digestion of fatty articles of food in the intestines.

Chyme (Gr. χυμός, juice). The pulpy liquid formed by digestion in the stomach.

Cilia (pl. of _cilium_, an eyelash). Minute hair-like processes found upon the cells of the air passages and other parts.

Ciliary Muscle. A small muscle of the eye which assists in accommodation.

Circumvallate (Lat. _circum_, around, and _vallum_, a rampart). Surrounded by a rampart, as are certain papillæ of the tongue.

Coagulation (Lat. _coagulo_, to curdle). Applied to the process by which the blood clots or solidifies.

Cochlea (Lat. _cochlea_, a snail shell). The spiral cavity of the internal ear.

Columnæ Carneæ. Fleshy projections in the ventricles of the heart.

Commissure (Lat. _con_, together, and _mitto_, _missum_, to put). A joining or uniting together.

Compress. A pad or bandage applied directly to an injury to compress it.

Concha (Gr. κόγχη, a mussel shell). The shell-shaped portion of the external ear.

Congestion (Lat. _con_, together, and _gero_, to bring). Abnormal gathering of blood in any part of the body.

Conjunctiva (Lat. _con_, together, and _jungo_, 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.

Connective Tissue. The network which connects the minute parts of most of the structures of the body.

Constipation (Lat. _con_, together, and _stipo_, to crowd close). Costiveness.

Consumption (Lat. _consumo_, to consume). A disease of the lungs, attended with fever and cough, and causing a decay of the bodily powers. The medical name is _phthisis_.

Contagion (Lat. _con_, with, and _tango_ or _tago_, to touch). The communication of disease by contact, or by the inhalation of the effluvia of a sick person.

Contractility (Lat. _con_, together, and _traho_, to draw). The property of a muscle which enables it to contract, or draw its extremities closer together.

Convolutions (Lat. _con_, together, and _volvo_, to roll). The tortuous foldings of the external surface of the brain.

Convulsion (Lat. _convello_, to pull together). A more or less violent agitation of the limbs or body.

Coördination. The manner in which several different organs of the body are brought into such relations with one another that their functions are performed in harmony.

Coracoid (Gr. κόραξ, a crow, εἶδος, form). Shaped like a crow’s beak.

Cornea (Lat. _cornu_, a horn). The transparent horn-like substance which covers a part of the front of the eyeball.

Coronary (Lat. _corona_, a crown). A term applied to vessels and nerves which encircle parts, as the _coronary_ arteries of the heart.

Coronoid (Gr. κορώνη, a crow). Like a crow’s beak; thus the _coronoid_ process of the ulna.

Cricoid (Gr. κρίκος, a ring, and εἶδος, form). A cartilage of the larynx resembling a seal ring in shape.

Crystalline Lens (Lat. _crystallum_, a crystal). One of the humors of the eye; a double-convex body situated in the front part of the eyeball.

Cumulative. A term applied to the violent action from drugs which supervenes after the taking of several doses with little or no effect.

Cuticle (Lat. dim. of _cutis_, the skin). Scarf skin; the epidermis.

Cutis (Gr. σκῦτος, a skin or hide). The true skin, also called the _dermis_.

Decussation (Lat. _decusso_, _decussatum_, to cross). The _crossing_ or running of one portion athwart another.

Degeneration (Lat. _degenerare_, to grow worse, to deteriorate). A change in the structure of any organ which makes it less fit to perform its duty.

Deglutition (Lat. _deglutire_, to swallow). The process of swallowing.

Deltoid. Having a triangular shape; resembling the Greek letter Δ (_delta_).

Dentine (Lat. _dens_, _dentis_, a tooth). The hard substance which forms the greater part of a tooth; ivory.

Deodorizer. An agent which corrects any foul or unwholesome odor.

Dextrin. A soluble substance obtained from starch.

Diabetes Mellitus (Gr. διά, through, βαίνω, to go, and μέλι, honey). Excessive flow of sugar-containing urine.

Diaphragm (Gr. διαφράσσω, to divide by a partition). A large, thin muscle which separates the cavity of the chest from the abdomen.

Diastole (Gr. διαστέλλω, to dilate). The _dilatation_ of the heart.

Dietetics. That part of medicine which relates to diet, or food.

Diffusion of Gases. The power of gases to become intimately mingled.

Diplöe (Gr. διπλόω, to double, to fold). The osseous tissue between the tables of the skull.

Dipsomania (Gr. δίψα, thirst, and μανία, madness). An insatiable desire for intoxicants.

Disinfectants. Agents used to destroy the germs or particles of living matter that are believed to be the causes of infection.

Dislocation (Lat. _dislocare_, to put out of place). An injury to a joint in which the bones are displaced or forced out of their sockets.

Dissection (Lat. _dis_, apart, and _seco_, to cut). The cutting up of an animal in order to learn its structure.

Distal (Lat. _dis_, apart, and _sto_, to stand). Away from the center.

Duct (Lat. _duco_, to lead). A narrow tube.

Duodenum (Lat. _duodeni_, twelve). The first division of the small intestines, about twelve fingers’ breadth long.

Dyspepsia (Gr. -δύς, ill, and πέπτειν, to digest). A condition of the alimentary canal in which it digests imperfectly. Indigestion.

Dyspnœa (Gr. δύς, difficult, and πνέω, to breathe). Difficult breathing.

Efferent (Lat. _effero_, to carry out). _Bearing_ or _carrying outwards_, as from the center to the periphery.

Effluvia (Lat. _effluo_, to flow out). Exhalations or vapors coming from the body, and from decaying animal or vegetable substances.

Element. One of the simplest parts of which anything consists.

Elimination (Lat. _e_, out of, and _limen, liminis_, a threshold). The act of _expelling_ waste matters. Signifies, literally, “to throw out of doors.”

Emetic (Gr. ἐμέω, to vomit). A medicine which causes vomiting.

Emulsion (Lat. _emulgere_, to milk). Oil in a finely divided state, suspended in water.

Enamel (Fr. _émail_). Dense material covering the crown of a tooth.

Endolymph (Gr. ἔνδον, within, and Lat. _lympha_, water). The fluid in the membranous labyrinth of the ear.

Endosmosis (Gr. ἔνδον, within, and ὠθέω, to push). The current from without _inwards_ when diffusion of fluids takes place through a membrane.

Epidemic (Gr. ἐπί, upon, and δέμος, the people). An extensively prevalent disease.

Epiglottis (Gr. ἐπί, upon, and γλόττις, the entrance to the windpipe). A leaf-shaped piece of cartilage which covers the top of the larynx during the act of swallowing.

Epilepsy (Gr. ἐπίληψις, a seizure). A nervous disease accompanied by fits in which consciousness is lost; the falling sickness.

Ether (Gr. αἰθήρ, the pure, upper air). A narcotic poison. Used as an anæsthetic in surgical operations.

Eustachian (from an Italian anatomist named Eustachi). The tube which leads from the throat to the middle ear, or tympanum.

Excretion (Lat. _excerno_, to separate). The separation from the blood of the waste matters of the body; also the materials excreted.

Exosmosis (Gr. ἔξω, without, and ᾀθέω, to push). The current from within _outwards_ when diffusion of fluids takes place through a membrane.

Expiration (Lat. _expiro_, to breathe out). The act of forcing air out of the lungs.

Extension (Lat. _ex_, out, and _tendo_, to stretch). The act of restoring a limb, etc., to its natural position after it has been flexed or bent; the opposite of _flexion_.

Fauces. The part of the mouth which opens into the pharynx.

Fenestra (Lat.). Literally, “a window.” Fenestra ovalis and fenestra rotunda, the oval and the round window; two apertures in the bone between the tympanic cavity and the labyrinth of the ear.

Ferment. That which causes fermentation, as yeast.

Fermentation (Lat. _fermentum_, boiling). The process of undergoing an effervescent change, as by the action of yeast; in a wider sense, the change of organized substances into new compounds by the action of a ferment. It differs in kind according to the nature of the ferment.

Fiber (Lat. _fibra_, a filament). One of the tiny threads of which many parts of the body are composed.

Fibrilla. A little fiber; one of the longitudinal threads into which a striped muscular fiber can be divided.

Fibrin (Lat. _fibra_, a fiber). An albuminoid substance contained in the flesh of animals, and also produced by the coagulation of blood.

Flexion (Lat. _flecto_, to bend). The act of bending a limb, etc.

Follicle (Lat. dim. of _follis_, a money bag). A little pouch or depression.

Fomentation (Lat. _foveo_, to keep warm). The application of any warm, medicinal substance to the body, by which the vessels are relaxed.

Foramen. A hole, or aperture.

Frontal Sinus. A blind or closed cavity in the bones of the skull just over the eyebrows.

Fumigation (Lat. _fumigo_, to perfume a place). The use of certain fumes to counteract contagious effluvia.

Function (Lat. _functio_, a doing). The special duty of any organ.

Ganglion (Gr. γάγγλιν, a knot). A knot-like swelling in a nerve; a smaller nerve center.

Gastric (Gr. γαστήρ, stomach). Pertaining to the stomach.

Gelatine (Lat. _gelo_, to congeal). An animal substance which dissolves in hot water and forms a jelly on cooling.

Germ (Lat. _germen_, a sprout, bud). Disease germ; a name applied to certain tiny bacterial organisms which have been demonstrated to be the cause of disease.

Germicide (_Germ_, and Lat. _caedere_, to kill). Any agent which has a destructive action upon living germs, especially _bacteria_.

Gland (Lat. _glans_, an acorn). An organ consisting of follicles and ducts, with numerous blood-vessels interwoven.

Glottis (Gr. γλόττα, the tongue). The narrow opening between the vocal cords.

Glucose. A kind of sugar found in fruits, also known as grape sugar.

Gluten. The glutinous albuminoid ingredient of cereals.

Glycogen. Literally, “producing glucose.” Animal starch found in liver, which may be changed into glucose.

Gram. Unit of metric system, 15.43 grains troy.

Groin. The lower part of the abdomen, just above each thigh.

Gustatory (Lat. _gusto_, _gustatum_, to taste). Belonging to the sense of _taste_.

Gymnastics (Gr. γυμνάξω, to exercise). The practice of athletic exercises.

Hæmoglobin (Gr. αἷμα, blood, and Lat. _globus_, a globe or globule). A complex substance which forms the principal coloring constituent of the red corpuscles of the blood.

Hemispheres (Gr. ἡμί, half, and σφαῖρα, a sphere). Half a sphere, the lateral halves of the cerebrum, or brain proper.

Hemorrhage (Gr. αἷμα, blood, and ῥήγνυμι, to burst). Bleeding, or the loss of blood.

Hepatic (Gr. ἧπαρ, the liver). Pertaining to the liver.

Herbivorous (Lat. _herba_, an herb, and _voro_, to devour). Applied to animals that subsist upon vegetable food.

Heredity. The predisposition or tendency derived from one’s ancestors to definite physiological actions.

Hiccough. A convulsive motion of some of the muscles used in breathing, accompanied by a shutting of the glottis.

Hilum, sometimes written Hilus. A small fissure, notch, or depression. A term applied to the concave part of the kidney.

Homogeneous (Gr. ὁμός, the same, and γένος, kind). Of the _same kind_ or quality throughout; uniform in nature,—the reverse of heterogeneous.

Humor. The transparent contents of the eyeball.

Hyaline (Gr. ὕαλος, glass). Glass-like, resembling glass in transparency.

Hydrogen. An elementary gaseous substance, which, in combination with oxygen, produces water.

Hydrophobia (Gr. ὕδωρ, water, and φοβέομαι, to fear). A disease caused by the bite of a rabid dog or other animal.

Hygiene (Gr. ὑγἰεια health). The art of preserving health and preventing disease.

Hyoid (Gr. letter υ, and εἰδος, form, resemblance). The bone at the root of the tongue, shaped like the Greek letter υ.

Hypermetropia (Gr. ὑπέρ over, beyond, μέτρον, measure, and ώ̓ψ, the eye). Far-sightedness.

Hypertrophy (Gr. ὑπέρ, over, and τροφή, nourishment). Excessive growth; thickening or enlargement of any part or organ.

Incisor (Lat. _incido_, to cut). Applied to the four front teeth of both jaws, which have sharp, cutting edges.

Incus. An anvil; the name of one of the bones of the middle ear.

Indian Hemp. The common name of _Cannabis Indica_, an intoxicating drug known as _hasheesh_ and by other names in Eastern countries.

Inferior Vena Cava. The chief vein of the lower part of the body.

Inflammation (Lat. prefix _in_ and _flammo_, to flame). A redness or swelling of any part of the body with heat and pain.

Insalivation (Lat. _in_ and _saliva_, the fluid of the mouth). The mingling of the saliva with the food during the act of chewing.

Inspiration (Lat. _inspiro, spiratum_, to breathe in). The act of drawing in the breath.

Intestine (Lat. _intus_, within). The part of the alimentary canal which is continuous with the lower end of the stomach; also called the bowels.

Iris (Lat. _iris_, the rainbow). The thin, muscular ring which lies between the cornea and crystalline lens, giving the eye its special color.

Jaundice (Fr. _jaunisse_, yellow). A disorder in which the skin and eyes assume a yellowish tint.

Katabolism (Gr. καταβάλλω, to throw down). The process by means of which the more complex elements are rendered more simple and less complex. The opposite of _anabolism_.

Labyrinth. The internal ear, so named from its many windings.

Lacrymal Apparatus (Lat. _lacryma_, a tear). The organs for forming and carrying away the tears.

Lacteals (Lat. _lac, lactis_, milk). The absorbent vessels of the small intestines.

Laryngoscope (Gr. λάρυγξ, larynx, and σκοπέω, to behold). An instrument consisting of a mirror held in the throat, and a reflector to throw light on it, by which the interior of the larynx is brought into view.

Larynx. The cartilaginous tube situated at the top of the windpipe.

Lens. Literally, a lentil; a piece of transparent glass or other substance so shaped as either to converge or disperse the rays of light.

Ligament (Lat. _ligo_, to bind). A strong, fibrous material binding bones or other solid parts together.

Ligature (Lat. _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 (Lat. _lympha_, pure water). The watery fluid conveyed by the lymphatic vessels.

Lymphatic Vessels. A system of absorbent vessels.

Malleus. Literally, the mallet; one of the small bones of the middle ear.

Marrow. The soft, fatty substance contained in the cavities of bones.

Mastication (Lat. _mastico_, to chew). The act of cutting and grinding the food to pieces by means of the teeth.

Meatus (Lat. _meo_, _meatum_, to pass). A _passage_ or canal.

Medulla Oblongata. The “oblong marrow”; that portion of the brain which lies upon the basilar process of the occipital bone.

Meibomian. A term applied to the small glands between the conjunctiva and tarsal cartilages, discovered by _Meibomius_.

Membrana Tympani. Literally, the membrane of the drum; a delicate partition separating the outer from the middle ear; it is sometimes popularly called “the drum of the ear.”

Membrane. A thin layer of tissue serving to cover some part of the body.

Mesentery (Gr. μέσος, middle, and ἔντερον, the intestine). A duplicature of the peritoneum covering the small _intestine_, which occupies the _middle_ or center of the abdominal cavity.

Metabolism (Gr. μεταβολή, change). The _changes_ taking place in cells, whereby they become more complex and contain more force, or less complex and contain less force. The former is constructive metabolism, or _anabolism_; the latter, destructive metabolism, or _katabolism_.

Microbe (Gr. μικρός, little, and βίος, life). A microscopic organism, particularly applied to bacteria.

Microscope (Gr. μικρός, small, and σκοπέω, to look at). An optical instrument which assists in the examination of minute objects.

Molar (Lat. _mola_, a mill). The name applied to the three back teeth at each side of the jaw; the grinders, or mill-like teeth.

Molecule (dim. of Lat. _moles_, a mass). The smallest quantity into which the mass of any substance can physically be divided. A molecule may be chemically separated into two or more atoms.

Morphology (Gr. μόρφη, form, and λόγος, discourse). The study of the laws of form or structure in living beings.

Motor (Lat. _moveo_, _motum_, to move). The name of the nerves which conduct to the muscles the stimulus which causes them to contract.

Mucous Membrane. The thin layer of tissue which covers those internal cavities or passages which communicate with the external air.

Mucus. The glairy fluid secreted by mucous membranes.

Myopia (Gr. μύω, to shut, and ὤψ, the eye). A defect of vision dependent upon an eyeball that is too long, rendering distant objects indistinct; _near sight_.

Myosin (Gr. μῶς, muscle). Chief proteid substance of muscle.

Narcotic (Gr. ναρκάω, to benumb). A medicine which, in poisonous doses, produces stupor, convulsions, and sometimes death.

Nerve Cell. A minute round and ashen-gray cell found in the brain and other nervous centers.

Nerve Fiber. An exceedingly slender thread of nervous tissue.

Nicotine. The poisonous and stupefying oil extracted from tobacco.

Nostril (Anglo-Saxon _nosu_, nose, and _thyrl_, a hole). One of the two outer openings of the nose.

Nucleolus (dim. of _nucleus_). A little nucleus.

Nucleus (Lat. _nux_, a nut). A central part of any body, or that about which matter is collected. In anatomy, a cell within a cell.

Nutrition (Lat. _nutrio_, to nourish). The processes by which the nourishment of the body is accomplished.

Odontoid (Gr. ὀδούς, a tooth, εἶδσ, shape). The name of the bony peg of the second vertebra, around which the first turns.

Œsophagus. Literally, that which carries food. The tube leading from the throat to the stomach; the gullet.

Olecranon (Gr. ὠλένη, the elbow, and κρανίον, the top of the head). A curved eminence at the upper and back part of the ulna.

Olfactory (Lat. _olfacio_, to smell). Pertaining to the sense of smell.

Optic (Gr. ὀπτεύω, to see). Pertaining to the sense of sight.

Orbit (Lat. _orbis_, a circle). The bony socket or cavity in which the eyeball is situated.

Organ (Lat. _organum_, an instrument or implement). A portion of the body having some special function or duty.

Osmosis (Gr. ὠσμός, impulsion). Diffusion of liquids through membranes.

Ossa Innominata, pl. of Os Innominatum (Lat.). “Unnamed bones.” The irregular bones of the pelvis, unnamed on account of their non-resemblance to any known object.

Otoconia (Gr. οὖς, an ear, and κονία, dust). Minute crystals of lime in the vestibule of the ear; also known as _otoliths_.

Palate (Lat. _palatum_, the palate). The roof of the mouth, consisting of the hard and soft palate.

Palpitation (Lat. _palpitatio_, a frequent or throbbing motion). A violent and irregular beating of the heart.

Papilla. The small elevations found on the skin and mucous membranes.

Paralysis (Gr. παραλύω, to loosen; also, to disable). Loss of function, especially of motion or feeling. Palsy.

Parasite. A plant or animal that grows or lives on another.

Pelvis. Literally, a basin. The bony cavity at the lower part of the trunk.

Pepsin (Gr. πέπτω, to digest). The active principle of the gastric juice.

Pericardium (Gr. περί, about, and καρδία, heart). The sac enclosing the heart.

Periosteum (Gr. περί, around, ὀστέον, a bone). A delicate fibrous membrane which invests the bones.

Peristaltic Movements (Gr. περί, round, and στέλλω, to send). The slow, wave-like movements of the stomach and intestines.

Peritoneum (Gr. περιτείνω, to stretch around). The investing membrane of the stomach, intestines, and other abdominal organs.

Perspiration (Lat. _perspiro_, to breathe through). The sweat.

Petrous (Gr. πέτρα, a rock). The name of the hard portion of the temporal bone, in which are situated the drum of the ear and labyrinth.

Phalanges (Gr. φάλαγξ, a body of soldiers closely arranged in ranks and files). The bones of the fingers and toes.

Pharynx (Gr. φάρμγξ, the throat). The cavity between the back of the mouth and the gullet.

Physiology (Gr. φύσις, nature, and λόγος, a discourse). The science of the functions of living, organized beings.

Pia Mater (Lat.). Literally, the tender mother; the innermost of the three coverings of the brain. It is thin and delicate; hence the name.

Pinna (Lat. a feather or wing). External cartilaginous flap of the ear.

Plasma (Gr. πλάσσω, to mould). Anything formed or moulded. The liquid part of the blood.

Pleura (Gr. πλευρά, the side, also a rib). A membrane covering the lung, and lining the chest.

Pleurisy. An inflammation affecting the pleura.

Pneumogastric (Gr. πνεύμων, the lungs, and γαστήρ, the stomach). The chief nerve of respiration; also called the _vagus_, or wandering nerve.

Pneumonia. An inflammation affecting the air cells of the lungs.

Poison (Fr. _poison_). Any substance, which, when applied externally, or taken into the stomach or the blood, works such a change in the animal economy as to produce disease or death.

Pons Varolii. Bridge of Varolius. The white fibers which form a _bridge_ connecting the different parts of the brain, first described by _Varolius_.

Popliteal (Lat. _poples_, _poplitis_, the ham, the back part of the knee). The space _behind the knee joint_ is called the _popliteal_ space.

Portal Vein (Lat. _porta_, a gate). The venous trunk formed by the veins coming from the intestines. It carries the blood to the liver.

Presbyopia (Gr. πρέσβυς, old, and ὤψ, 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.

Process (Lat. _procedo_, _processus_, to proceed, to go forth). Any projection from a surface; also, a method of performance; a procedure.

Pronation (Lat. _pronus_, inclined forwards). The turning of the hand with the palm downwards.

Pronator. The group of muscles which turn the hand palm downwards.

Proteids (Gr. πρῶτος, first, and εἶδος, form). A general term for the albuminoid constitutents of the body.

Protoplasm (Gr. πρῶτος, first, and πλάσσω, to form). A _first-formed_ organized substance; primitive organic cell matter.

Pterygoid (Gr. πτέρων, a wing, and εἶδος, form, resemblance). Wing-like.

Ptomaine (Gr. πτῶμα, a dead body). One of a class of animal bases or alkaloids formed in the putrefaction of various kinds of albuminous matter.

Ptyalin (Gr. σίαλον, saliva). A ferment principle in _saliva_, having power to convert starch into sugar.

Pulse (Lat. _pello, pulsum_, to beat). The throbbing of an artery against the finger, occasioned by the contraction of the heart. Commonly felt at the _wrist_.

Pupil (Lat. _pupilla_). The central, round opening in the iris, through which light passes into the interior of the eye.

Pylorus (Gr. πυλουρός, a gatekeeper). The lower opening of the stomach, at the beginning of the small intestine.

Reflex (Lat. _reflexus_, turned back). The name given to involuntary movements produced by an excitation traveling along a sensory nerve to a center, where it is turned back or reflected along motor nerves.

Renal (Lat. _ren_, _renis_, the kidney). Pertaining to the _kidneys_.

Respiration (Lat. _respiro_, to breathe frequently). The function of breathing, comprising two acts,—_inspiration_, or breathing in, and _expiration_, or breathing out.

Retina (Lat. _rete_, a net). The innermost of the three tunics, or coats, of the eyeball, being an expansion of the optic nerve.

Rima Glottidis (Lat. _rima_, a chink or cleft). The _opening_ of the glottis.

Saccharine (Lat. _saccharum_, sugar). The group of food substances which embraces the different varieties of sugar, starch, and gum.

Saliva. The moisture, or fluids, of the mouth, secreted by the salivary glands; the spittle.

Sarcolemma (Gr. σάρξ, flesh, and λέμμα, a husk). The membrane which surrounds the contractile substance of a striped muscular fiber.

Sclerotic (Gr. σκληρός, hard). The tough, fibrous, outer coat of the eyeball.

Scurvy. Scorbutus,—a disease of the general system, having prominent skin symptoms.

Sebaceous (Lat. _sebum_, fat). Resembling fat; the name of the oily secretion by which the skin is kept flexible and soft.

Secretion (Lat. _secerno_, _secretum_, to separate). The process of separating from the blood some essential, important fluid; which fluid is also called a _secretion_.

Semicircular Canals. Three canals in the internal ear.

Sensation. The perception of an external impression by the nervous system.

Serum. The clear, watery fluid which separates from the clot of the blood.

Spasm (Gr. σπασμός, convulsion). A sudden, violent, and involuntary contraction of one or more muscles.

Special Sense. A sense by which we receive particular sensations, such as those of sight, hearing, taste, and smell.

Sputum, pi. Sputa (Lat. _spuo_, _sputum_, to _spit_). The matter which is coughed up from the air passages.

Stapes. Literally, a stirrup; one of the small bones of the middle ear.

Stimulant (Lat. _stimulo_, to prick or goad on). An agent which causes an increase of vital activity in the body or in any of its parts.

Striated (Lat. _strio_, to furnish with channels). Marked with fine lines.

Styptics (Gr. στυπτικός astringent). Substances used to produce a contraction or shrinking of living tissues.

Subclavian Vein (Lat. _sub_, under, 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.

Superior Vena Cava (Lat., upper hollow vein). The great vein of the upper part of the body.

Suture (Lat. _sutura_, a seam). The union of certain bones of the skull by the interlocking of jagged edges.

Sympathetic System of Nerves. A double chain of nervous ganglia, situated chiefly in front of, and on each side of, the spinal column.

Symptom (Gr. σύν, with, and πίπτω, to fall). A sign or token of disease.

Synovial (Gr. σύν, with, and ὠόν, an egg). The liquid which lubricates the joints; joint-oil. It resembles the white of a raw egg.

System. A number of different organs, of similar structures, distributed throughout the body and performing similar functions.

Systemic. Belonging to the system, or body, as a whole.

Systole (Gr. συστέλλω, to contract). The contraction of the heart, by which the blood is expelled from that organ.

Tactile (Lat. _tactus_, touch). Relating to the sense of touch.

Tartar. A hard crust which forms on the teeth, and is composed of salivary mucus, animal matter, and a compound of lime.

Temporal (Lat. _tempus_, time, and _tempora_, the temples). Pertaining to the temples; so called because the hair begins to turn white with age in that portion of the scalp.

Tendon (Lat. _tendo_, to stretch). The white, fibrous cord, or band, by which a muscle is attached to a bone; a sinew.

Tetanus (Gr. τείνω, to stretch). A disease marked by persistent contractions of all or some of the voluntary muscles; those of the jaw are sometimes solely affected; the disorder is then termed lockjaw.

Thorax (Gr. θώραξ, a breast-plate). The upper cavity of the trunk of the body, containing the lungs, heart, etc.; the chest.

Thyroid (Gr. εἶδος, a shield, and εἶ̓δος, form). The largest of the cartilages of the larynx: its projection in front is called “Adam’s Apple.”

Tissue. Any substance or texture in the body formed of various elements, such as cells, fibers, blood-vessels, etc., interwoven with each other.

Tobacco (Indian _tabaco_, the tube, or pipe, in which the Indians smoked the plant). A plant used for smoking and chewing, and in snuff.

Trachea (Gr. τραχύς, rough). The windpipe.

Tragus (Gr. τράγος, a goat). The eminence in front of the opening of the ear; sometimes hairy, like a goat’s beard.

Transfusion (Lat. _transfundo_, to pour from one vessel to another). The operation of injecting blood taken from one person into the veins of another.

Trichina Spiralis. (A twisted hair). A minute species of parasite, or worm, which infests the flesh of the hog: may be introduced into the human system by eating pork not thoroughly cooked.

Trochanter (Gr. τροχάω, to turn, to revolve). Name given to two projections on the upper extremities of the femur, which give attachment to the _rotator_ muscles of the thigh.

Trypsin. The ferment principle in pancreatic juice, which converts proteid material into peptones.

Tubercle (Lat. _tuber_, a bunch). A pimple, swelling, or tumor. A morbid product occurring in certain lung diseases.

Tuberosity (Lat. _tuber, tuberis_, a swelling). A protuberance.

Turbinated (Lat. _turbinatus_, from _turbo, turbinis_, a top). Formed like a _top_; a name given to the bones in the outer wall of the nasal fossæ.

Tympanum (Gr. τύμπανον, a drum). The cavity of the middle ear, resembling a drum in being closed by two membranes.

Umbilicus (Lat., the navel.) A round cicatrix or scar in the median line of the abdomen.

Urea (Lat. _urina_, urine). Chief solid constitutent of _urine_. Nitrogenous product of tissue decomposition.

Ureter (Gr. οὐρέω, to pass urine). The tube through which the _urine_ is conveyed from the kidneys to the bladder.

Uvula (Lat. _uva_, a grape). The small, pendulous body attached to the back part of the palate.

Vaccine Virus (Lat. _vacca_, a cow, and _virus_, poison). The material derived from heifers for the purpose of vaccination,—the great preventive of smallpox.

Valvulae Conniventes. A name given to transverse folds of the mucous membrane in the small intestine.

Varicose (Lat. _varix_, a dilated vein). A distended or enlarged vein.

Vascular (Lat. _vasculum_, a little vessel). Pertaining to or possessing blood or lymph vessels.

Vaso-motor (Lat. _vas_, a vessel, and _moveo, motum_, to move). Causing _motion_ to the _vessels_. Vaso-motor nerves cause contraction and relaxation of the blood-vessels.

Venæ Cavæ, pl. of Vena Cava. “Hollow veins.” A name given to the two great veins of the body which meet at the right auricle of the heart

Venous (Lat. _vena_, a vein). Pertaining to, or contained within, a vein. Ventilation. The introduction of fresh air into a room or building in such a manner as to keep the air within it in a pure condition.

Ventral (Lat. _venter, ventris_, the belly). Belonging to the abdominal or belly cavity.

Ventricles of the Heart. The two largest cavities of the heart.

Vermiform (Lat. _vermis_, a worm, and _forma_, form). Worm-shaped.

Vertebral Column (Lat. _vertebra_, a joint). The backbone; also called the spinal column and spine.

Vestibule. A portion of the internal ear, communicating with the semicircular canals and the cochlea, so called from its fancied resemblance to the vestibule, or porch, of a house.

Villi (Lat. _villus_, shaggy hair). Minute, thread-like projections upon the internal surface of the small intestine, giving it a velvety appearance.

Virus (Lat., poison). Foul matter of an ulcer; poison.

Vital Knot. A part of the medulla oblongata, the destruction of which causes instant death.

Vitreous (Lat. _vitrum_, glass). Having the appearance of glass; applied to the humor occupying the largest part of the cavity of the eyeball.

Vivisection (Lat. _vivus_, alive, and _seco_, to cut). The practice of operating upon living animals, for the purpose of studying some physiological process.

Vocal Cords. Two elastic bands or ridges situated in the larynx; the essential parts of the organ of voice.

Zygoma (Gr. ζυγώς, a yoke). The arch formed by the malar bone and the zygomatic process of the temporal bone.

Index.

Absorption from mouth and stomach by the intestines Accident and emergencies Achilles, Tendon of Air, made impure by breathing Foul, effect of, on health Alcohol, Effect of, on bones Effect of, on muscles Effect of, on muscular tissue Effect of, on physical culture Nature of Effects of, on human system and digestion Effect of, on the stomach and the gastric juice Final results on digestion Effects of, on the liver Fatty degeneration due to Effect of, on the circulation Effect of, on the heart Effect of, on the blood-vessels Effect of, on the lungs Other results of, on lungs Effect of, on disease Effect of, on kidneys Alcohol as cause of Bright’s disease and the brain How, injures the brain Why brain suffers from the enemy of brain work Other physical results of Diseases produced by Mental and moral ruin by Evil results of, inherited Effect of, on taste Effect of, on the eye Effect of, on throat and voice Alcoholic beverages Alcoholic fermentation and Bacteria Anabolism defined Anatomy defined Antidotes for poisons Antiseptics Apparatus, Question of Arm, Upper Arteries Astigmatism Asphyxia Atlas and axis Atmosphere, how made impure

Bacteria, Nature of Bacteria, Struggle for existence of Importance of, in Nature Action of Battle against Baths and bathing Bathing, Rules and precautions Bicycling Bile Biology defined Bladder Bleeding, from stomach from lungs from nose How to stop Blood, Circulation of Physical properties of corpuscles Coagulation of General plan of circulation Blood-vessels, Nervous control of connected with heart Effect of alcohol on Injuries to Bodies, living, Characters of Body, General plan of Bone, Chemical composition of Physical properties of Microscopic structure of Bones, uses of, The Kinds of in infancy and childhood positions at school in after life Broken broken, Treatment for Effect of alcohol on Effect of tobacco on Breathing, Movements of Breathing, Mechanism of Varieties of Nervous control of change in the air Air, made impure by Brain, as a whole Membranes of as a reflex center Effects of alcohol on Brain center, Functions of, in perception of impressions Bright’s disease caused by alcohol Bronchial tubes Burns or scalds

Capillaries Carbohydrates Carpus Cartilage Hyaline White fibro- Yellow fibro- Thyroid Arytenoid Cricoid Cells and the human organism Kinds of Vital properties of Epithelial Nerve Cerebrum Cerebellum Chemical compounds in the body Chloral Chyle Chyme Cilia of air passages Circulation General plan of Portal Pulmonic Systemic Effect of alcohol on Clavicle Cleanliness, Necessity for Clothing, Use of Material used for Suggestions for use of Effects of tight-fitting Miscellaneous hints on use of Catching, on fire Coagulation of blood Cocaine, ether, and chloroform Cochlea of ear Cocoa Coffee Colon Color-blindness Complemental air Compounds, Chemical Organic Condiments Conjunctiva Connective tissue Consonants Contagious diseases Contraction, Object of Contusions and bruises Convulsions Cooking Coughing Cornea Corpuscles, Blood Red Colorless Corti, Organ of Cranial Nerves Cranium, Bones of Crying Crystalline lens Cuticle Cutis vera, or true skin

Degeneration, Fatty, due to alcohol Deglutition, or swallowing Deodorants Diet, Important articles of Effect of occupation on Too generous Effect of climate on Digestion, Purpose of General plan of in small intestines in large intestines Effect of alcohol on Disease, Effect of alcoholics upon Diseases, infectious and contagious, Management of Care of Hints on nursing Disinfectants Air and water as How to use Dislocations Dogs, mad, Bites of Drowning, Apparent Methods of treating Sylvester method Marshall Hall method Duct, Hepatic Cystic Common bile Thoracic Nasal Duodenum Dura mater

Ear, External Middle Bones of the Internal Practical hints on care of Foreign bodies in Eating, Practical points about Eggs as food Elements, Chemical, in the body Epidermis, or cuticle Epiglottis Epithelium Squamous Columnar Glandular Ciliated Epithelial tissues, Functions of Erect position Ethmoid bone Eustachian tube Excretion Exercise, Physical Importance of Effect of, on muscles Effect of, on important organs Effect of, on personal appearance Effect of excessive Amount of, required Time for Physical, in school Practical points about Effect of alcohol and tobacco on Experiments, Limitations of Value of Eye Inner structure of Compared to camera Refractive media of Movements of Foreign bodies in Practical hints on care of Effect of alcohol on Effect of tobacco on Eyeball, Coats of Eyelids and eyebrows Eyesight in schools

Face Bones of the Fainting Fats and oils Femur Fibrin Fibula Fish as food Food and drink Food, why we need it Absorption of, by the blood Quantity of, as affected by age Kinds of, required Foods, Classification of Nitrogenous Proteid Saline or mineral Vegetable Proteid vegetable Non-proteid vegetable Non-proteid animal Table of Food materials, Table of Composition of Foot Foul air, Effect of, on health Frontal bone Frost bites Fruits as food

Gall bladder Garden vegetables Gastric glands Gastric juice, Effect of alcohol on Glands Mesenteric Lymphatic Ductless Thyroid Thymus Suprarenal Lacrymal Glottis

Hair Structure of Hair and nails, Care of Hall, Marshall, method for apparent drowning Hand Haversian canals Head and spine, how joined Head, Bones of Hearing, Sense of Mechanism of Effect of tobacco on Heart Valves of General plan of blood-vessels connected with Rhythmic action of Impulse and sounds of Nervous control of Effect of alcohol on Effect of tobacco on Heat, Animal Sources of Hiccough Hip bones Histology defined Humerus Hygiene defined Hyoid bone Hypermetropia

Ileum Injured, Prompt aid to Insalivation Intestine, Small Coats of small Large Intoxicants, Physical results of Iris of the eye

Jejunum Joints Imperfect Perfect Hinge Ball-and-socket Pivot

Katabolism defined Kidneys Structure of Function of Action if, how modified Effect of alcohol on Kidneys and skin

Lacrymal apparatus gland Lacteals Landmarks, Bony Muscular heart arteries Larynx Laughing Lens, Crystalline Levers in the body Life, The process of Ligaments Limbs, Upper Lower Liver Minute structure of Blood supply of Functions of Effect of alcohol on Lungs Minute structure of Capacity of Effect of alcohol on Bleeding from Lymph Lymphatics

Mad dogs, Bites of Malar bone Mastication Maxillary, Superior Inferior Meals, Hints about Meats as food Medulla oblongata Membrane, Synovial Serous Arachnoid Membranes, Brain Mesentery Metabolism defined Metacarpal bones Metatarsal bones Microscope, Use of Milk Mineral foods Morphology defined Motion in animals Mouth Movement, Mechanism of Muscles, Kinds of voluntary, Structure of involuntary, Structure of Arrangement of Important Effect of alcohol on Effect of tobacco on Review analysis of Rest for Muscular tissue, Effect of alcohol on Changes in Properties of activity contraction fatigue sense Myopia

Nails Care of Nasal bones Nerve cells fibers cells and fibers, Function of Nerves, Cranial Spinal Motor Sensory spinal, Functions of Nervous system, General view of compared to telegraph system Divisions of Effect of alcohol on Effect of tobacco on Nitrogenous foods. Non-proteid vegetable foods animal foods Nose, Bleeding from Foreign bodies in

Occipital bone Œsophagus Opium Poisonous effects of In patent medicines Victim of the, habit Organic compounds Outdoor games Oxidation

Pain, Sense of Palate bones Pancreas Pancreatic juice Parietal bones Patella Pepsin Pericardium Periosteum Peritoneum Phalanges Pharynx and œsophagus Physical exercise Physical education in school Physical exercises in school Physiology defined Study of what it should teach Main problems of, briefly stated. Physiological knowledge, Value of Pia mater Pneumogastric nerve Poisons Poisons, Table of Antidotes for Practical points about Poisoning, Treatment of Portal circulation Portal vein Presbyopia Pressure, Where to apply Proteids Proteid vegetable foods Protoplasm Pulmonary artery veins Pulmonary infection Pulse Pupil of the eye

Radius Receptaculum chyli Rectum Reflex centers in the brain Reflex action, Importance of Renal secretion Residual air Respiration, Nature and object of Nervous control of Effect of, on the blood Effect of, on the air Modified movements of Effect of alcohol on Effect of tobacco on artificial, Methods of Rest, for the muscles Need of Benefits of The Sabbath, a day of of mind and body Retina Ribs and sternum

Saline or mineral foods Saliva Salt as food Salts, Inorganic, in the body Scalds or burns Scapula School, Physical education in Positions at School and physical education Secretion Semicircular canals Sensations, General Sensation, Conditions of Sense, Organs of Sense organ, The essentials of Serous membranes Sick-room, Arrangement of Ventilation of Hints for Rules for Sighing Sight, Sense of Skating, swimming, and rowing Skeleton Review analysis of Skeleton and manikin, Use of Skin, The regulating temperature Action of, how modified Absorbent powers of and the kidneys Skull Sutures of Sleep, a periodical rest Effect of, on bodily functions Amount of, required Practical rules about Smell Sense of Sneezing Snoring Sobbing Special senses Speech Sphenoid bone Spinal column Spinal cord Structure of Functions of conductor of impulses as a reflex center Spinal nerves Functions of Spleen Sprains and dislocations Stammering Starches and sugars Sternum Stomach Coats of Digestion in Effect of alcohol on Bleeding from Strabismus Stuttering Sunstroke Supplemental air Suprarenal capsules Sutures of skull Sweat glands Sweat, Nature of Sylvester method for apparent drowning Sympathetic system Functions of Synovial membrane sheaths and sacs

Taste, Organ of Sense of Taste, Physiological conditions of Modifications of the sense Effect of alcohol on Effect of tobacco on Tea Tear gland and tear passages Tears Technical terms defined Teeth Development of Structure of Proper care of Hints about saving Temperature, Regulation of bodily Skin as a regulator of Voluntary regulation of Sense of Temporal bones Tendon of Achilles Tendons Thigh Thoracic duct Throat Care of Effect of alcohol on Effect of tobacco on Foreign bodies in Thymus gland Thyroid gland Tibia Tidal air Tissue, White fibrous Connective Yellow elastic Areolar Adipose Adenoid Muscular Tissues, Epithelial Tissues, epithelial, Varieties of Functions of Connective Tobacco, Effect of, on bones Effect of, on muscles Effect of, on physical culture Effect of, on digestion Effect of, on the heart Effect of, on the lungs Effect of, on the nervous system Effect of, on the mind Effect of, on the character Effect of, on taste Effect of, on hearing Effect of, on throat and voice Touch, Organ of Sense of Trachea Trunk, Bones of Tympanum, Cavity of

Ulna Urine

Valve, Mitral Valves of the heart Valves, Tricuspid Semilunar Vegetable foods Veins Ventilation Conditions of efficient of sick-room Vestibule of ear Vermiform appendix Vision, Common defects of Effect of tobacco on Vivisection and dissection Vocal cords Voice, Mechanism of Factors in the production of Care of Effect of alcohol on Effect of tobacco on Vowel sounds

Walking, jumping, and running Waste and repair Waste material, Nature of Waste products, Elimination of Water as food Whispering Wounds, Incised and lacerated

Yawning

Footnotes

[1] The Value of Physiological Knowledge. “If any one doubts the importance of an acquaintance with the fundamental principles of physiology as a means to complete living, let him look around and see how many men and women he can find in middle life, or later, who are thoroughly well. Occasionally only do we meet with an example of vigorous health continued to old age; hourly do we meet with examples of acute disorder, chronic ailment, general debility, premature decrepitude. Scarcely is there one to whom you put the question, who has not, in the course of his life, brought upon himself illness from which a little knowledge would have saved him. Here is a case of heart disease consequent on a rheumatic fever that followed a reckless exposure. There is a case of eyes spoiled for life by overstudy. “Not to dwell on the natural pain, the gloom, and the waste of time and money thus entailed, only consider how greatly ill health hinders the discharge of all duties,—makes business often impossible, and always more difficult; produces irritability fatal to the right management of children, puts the functions of citizenship out of the question, and makes amusement a bore. Is it not clear that the physical sins—partly our ancestors’ and partly our own—which produce this ill health deduct more from complete living than anything else, and to a great extent make life a failure and a burden, instead of a benefaction and a pleasure?”—Herbert Spencer.

[2] The word protoplasm must not be misunderstood to mean a substance of a definite chemical nature, or of an invariable morphological structure; it is applied to any part of a cell which shows the properties of life, and is therefore only a convenient abbreviation for the phrase “mass of living matter.”

[3] “Did we possess some optic aid which should overcome the grossness of our vision, so that we might watch the dance of atoms in the double process of making and unmaking in the living body, we should see the commonplace, lifeless things which are brought by the blood, and which we call food, caught up into and made part of the molecular whorls of the living muscle, linked together for a while in the intricate figures of the dance of life, giving and taking energy as they dance, and then we should see how, loosing hands, they slipped back into the blood as dead, inert, used-up matter.”—Michael Foster, Professor of Physiology in the University of Cambridge, England.

[4] “Our material frame is composed of innumerable atoms, and each separate and individual atom has its birth, life, and death, and then its removal from the ‘place of the living.’ Thus there is going on a continuous process of decay and death among the individual atoms which make up each tissue. Each tissue preserves its vitality for a limited space only, is then separated from the tissue of which it has formed a part, and is resolved into its inorganic elements, to be in due course eliminated from the body by the organs of excretion.”—Maclaren’s _Physical Education_.

[5] The periosteum is often of great practical importance to the surgeon. Instances are on record where bones have been removed, leaving the periosteum, within which the entire bone has grown again. The importance of this remarkable tissue is still farther illustrated by experiments upon the transplantation of this membrane in the different tissues of living animals, which has been followed by the formation of bone in these situations. Some years ago a famous surgeon in New York removed the whole lower jawbone from a young woman, leaving the periosteum and even retaining in position the teeth by a special apparatus. The entire jawbone grew again, and the teeth resumed their original places as it grew.

[6] The mechanism of this remarkable effect is clearly shown by an experiment which the late Dr. Oliver Wendell Holmes used to take delight in performing in his anatomical lectures at the Harvard Medical College. He had a strong iron bar made into a ring of some eight inches in diameter, with a space left between the ends just large enough to be filled by an English walnut. The ring was then dropped to the floor so as to strike on the convexity just opposite to the walnut, which invariably was broken to pieces.

[7] For the treatment of accidents and emergencies which may occur with reference to the bones, see Chapter XIII.

[8] “Besides the danger connected with the use of alcoholic drinks which is common to them with other narcotic 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, ... and the cells being the living part of the animal, it is especially 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, of the New York Board of Health.

[9] “In its action on the system nicotine is one of the most powerful poisons known. A drop of it in a concentrated form was found sufficient to kill a dog, and small birds perished at the approach of a tube containing it.”—Wood’s _Materia Medica_. “Tobacco appears to chiefly affect the heart and brain, and I have therefore placed it among cerebral and cardiac poisons.”—Taylor’s _Treatise on Poisons_.

[10] “Certain events occur in the brain; these give rise to other events, to changes which travel along certain bundles of fibers called nerves, and so reach certain muscles. Arrived at the muscles, these changes in the nerves, which physiologists call nervous impulses, induce changes in the muscles, by virtue of which these shorten contract, bring their ends together, and so, working upon bony levers, bend the arm or hand, or lift the weight.”—Professor Michael Foster.

[11] The synovial membranes are almost identical in structure with serous membranes (page 176), but the secretion is thicker and more like the white of egg.

[12] “Smoking among students or men training for contests is a mistake. It not only affects the wind, but relaxes the nerves in a way to make them less vigorous for the coming contest. It shows its results at once, and when the athlete is trying to do his best to win he will do well to avoid it.” Joseph Hamblen Sears, Harvard Coach, and Ex-Captain of the Harvard Football Team, Article in _In Sickness and in Health_.

[13] “There is no profession, there is no calling or occupation in which men can be engaged, there is no position in life, no state in which a man can be placed, in which a fairly developed frame will not be valuable to him; there are many of these, even the most purely and highly intellectual, in which it is essential to success—essential simply as a means, material, but none the less imperative, to enable the mind to do its work. Year by year, almost day by day, we see men (and women) falter and fail in the midst of their labors; ... and all for want of a little bodily stamina—a little bodily power and bodily capacity for the endurance of fatigue, or protracted unrest, or anxiety, or grief.”—Maclaren’s _Physical Education_.

[14] “One half the struggle of physical training has been won when a boy 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 improving his physical condition, matters little, provided he accomplishes that object.”—Dr. D. A. Sargent, Director of the Hemenway Gymnasium at Harvard University.

[15] “It is _health_ rather than _strength_ that is the great requirement of modern men at modern occupations; it is not the power to travel great distances, carry great burdens, lift great weights, or overcome great material obstructions; it is simply that condition of body, and that amount of vital capacity, which shall enable each man in his place to pursue his calling, and work on in his working life, with the greatest amount of comfort to himself and usefulness to his fellowmen.”—Maclaren’s _Physical Education_.

[16] To this classification may be added what are called albuminoids, a group of bodies resembling proteids, but having in some respects a different nutritive value. Gelatine, such as is found in soups or table gelatine is a familiar example of the albuminoids. They are not found to any important extent in our raw foods, and do not therefore usually appear in the analyses of the composition of foods. The albuminoids closely resemble the proteids, but cannot be used like them to build up protoplasm.

[17] The amount of water in various tissues of the body is given by the following table in parts of 1000:

Solids. Liquids. Enamel, 2 Blood, 791 Dentine, 100 Bile, 864 Bone, 486 Blood plasma, 901 Fat, 299 Chyle, 928 Cartilage, 550 Lymph, 958 Liver, 693 Serum, 959 Skin, 720 Gastric juice, 973 Brain, 750 Tears, 982 Muscle, 757 Saliva, 995 Spleen, 758 Sweat, 995 Kidney, 827 Vitreous humor, 987

[18] The work of some kinds of moulds may be apparent to the eye, as in the growths that form on old leather and stale bread and cheese. That of others goes on unseen, as when acids are formed in stewed fruits. Concerning the work of the different kinds of moulds. Troussart says: “_Mucor mucedo_ devours our preserves; _Ascophora mucedo_ turns our bread mouldy; _Molinia_ is nourished at the expense of our fruits; _Mucor herbarium_ destroys the herbarium of the botanist; and _Choetonium chartatum_ develops itself on paper, on the insides of books and on their bindings, when they come in contact with a damp wall.”—Troussart’s _Microbes, Ferments, and Moulds_.

[19] “The physiological wear of the organism is constantly being repaired by the blood; but in order to keep the great nutritive fluid from becoming impoverished, the matters which it is constantly losing must be supplied from some source out of the body, and this necessitates the ingestion of articles which are known as food.”—Flint’s _Text-book of Human Physiology_.

[20] Glands. Glands are organs of various shapes and sizes, whose special work it is to separate materials from the blood for further use in the body, the products being known as secretion and excretion. The means by which secretion and excretion are effected are, however, identical. The essential parts of a gland consist of a basement membrane, on one side of which are found actively growing cells, on the other is the blood current, flowing in exceedingly thin-walled vessels known as the capillaries. The cells are able to select from the blood whatever material they require and which they elaborate into the particular secretion. In Fig. 47 is illustrated, diagrammatically, the structure of a few typical secreting glands. The continuous line represents the basement membrane. The dotted line represents the position of the cells on one side of the basement membrane. The irregular lines show the position of the blood-vessels.

[21] Tablets and other material for Fehling and additional tests for sugar can be purchased at a drug store. The practical details of these and other tests which assume some knowledge of chemistry, should be learned from some manual on the subject.

[22] The Peritoneum. The intestines do not lie in a loose mass in the abdominal cavity. Lining the walls of this cavity, just as in a general way, a paper lines the walls of a room, is a delicate serous membrane, called the peritoneum. It envelops, in a greater or less degree, all the viscera in the cavity and forms folds by which they are connected with each other, or are attached to the posterior wall. Its arrangement is therefore very complicated. When the peritoneum comes in contact with the large intestine, it passes over it just as the paper of a room would pass over a gas pipe which ran along the surface of the wall, and in passing over it binds it down to the wall of the cavity. The small intestines are suspended from the back wall of the cavity by a double fold of the peritoneum, called the mesentery. The bowels are also protected from external cold by several folds of this membrane loaded with fat. This is known as the _great omentum_. The peritoneum, when in health, secretes only enough fluid to keep its surface lubricated so that the bowels may move freely and smoothly on each other and on the other viscera. In disease this fluid may increase in amount, and the abdominal cavity may become greatly distended. This is known as _ascites_ or dropsy.

[23] The human bile when fresh is generally of a bright golden red, sometimes of a greenish yellow color. It becomes quite green when kept, and is alkaline in reaction. When it has been omited it is distinctly yellow, because of its action on the gastric juice. The bile contains a great deal of coloring matter, and its chief ingiedients are two salts of soda, sodium taurocholate and glycocholate.

[24] Nansen emphasizes this point in his recently published work, _Farthest North_.

[25] We should make it a point not to omit a meal unless forced to do so. Children, and even adults, often have the habit of going to school or to work in a hurry, without eating any breakfast. There is almost sure to be a fainting, or “all-gone” feeling at the stomach before another mealtime. This habit is injurious, and sure to produce pernicious results.

[26] The teeth of children should be often examined by the dentist, especially from the beginning of the second dentition, at about the sixth year, until growth is completed. In infancy the mother should make it a part of her daily care of the child to secure perfect cleanliness of the teeth. The child thus trained will not, when old enough to rinse the mouth properly or to use the brush, feel comfortable after a meal until the teeth have been cleansed. The habit thus formed is almost sure to be continued through life.

[27] “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 are associated catarrh of the stomach and liver with its characteristic symptoms,—loss of appetite, feeble digestion, sallowness, mental depression, and headache.”—James C. Wilson, Professor in the Jefferson Medical College, Philadelphia. “Man has recourse to alcohol, not for the minute quantity of energy which may be supplied by itself, but for its powerful influence on the distribution of the energy furnished by other things. That influence is a very complex one.”—Professor Michael Foster.

[28] “When constantly irritated by the direct action of alcoholic drinks, the stomach gradually undergoes lasting structural changes. Its vessels remain dilated and congested, its connective tissue becomes excessive, its power of secreting gastric juice diminishes, and its mucous secretions abnormally abundant.”—H. Newell Martin, late Professor of Physiology in Johns Hopkins University. “Chemical experiments have demonstrated that the action of alcohol on the digestive fluids is to destroy its active principle, the pepsin, thus confirming the observations of physiologists that its use gives ride to the most serious disorders of the stomach and the most malignant aberrations of the entire economy.”—Professor E. C. Youmans, author of standard scientific works. “The structural changes induced by habitual use of alcohol and the action of this agent on the pepsin, seriously impair the digestive power. Hence it is, that those who are habitual consumers of alcoholic fluids suffer from disorders o digestion.”—Robert Bartholow, recently Professor of Materia Medica in the University of Pennsylvania. “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.”—Professor W. B. Carpenter, the eminent English physiologist.

[29] “Cirrhosis of the liver is notoriously frequent among drunkards, and is in fact almost, though not absolutely, confined to them.”—Robert T. Edes, formerly Professor of Materia Medica in Harvard Medical College. “Alcohol acts on the liver by producing enlargement of that organ, and a fat deposit, or ‘hob-nailed’ liver mentioned by the English writers.”—Professor W. B. Carpenter.

[30] Preparation of Artificial Gastric Juice. _(a)_ Take part of the cardiac end of the pig’s stomach, which has been previously opened and washed rapidly in cold water, and spread it, mucous surface upwards, on the convex surface of an inverted capsule. Scrape the mucous surface firmly with the back of a knife blade, and rub up the scrapings in a mortar with fine sand. Add water, and rub up the whole vigorously for some time, and filter. The filtrate is an artificial gastric juice. _(b)_ From the cardiac end of a pig’s stomach detach the mucous membrane in shreds, dry them between folds of blotting-paper, place them in a bottle, and cover them with strong glycerine for several days. The glycerine dissolves the pepsin, and on filtering, a glycerine extract with high digestive properties is obtained. These artificial juices, when added to hydrochloric acid of the proper strength, have high digestive powers. Instead of _(a)_ or _(b)_ use the artificial pepsin prepared for the market by the wholesale manufacturers of such goods.

[31] The cause of the clotting of blood is not yet fully understood. Although the process has been thoroughly investigated we have not yet a satisfactory explanation why the circulating blood does not clot in healthy blood-vessels. The ablest physiologists of our day do not, as formerly, regard the process as a so-called vital, but a purely chemical one.

[32] Serous Membranes.—The serous membranes form shut sacs, of which one portion is applied to the walls of the cavity which it lines; the other is reflected over the surface of the organ or organs contained in the cavity. The sac is completely closed, so that no communication exists between the serous cavity and the parts in its neighborhood. The various serous membranes are the _pleura_ which envelops the lungs; the _pericardium_ which surrounds the heart; the _peritoneum_ which invests the viscera of the abdomen, and the _arachnoid_ in the spinal canal and cranial cavity. In health the serous membranes secrete only sufficient fluid to lubricate and keep soft and smooth the opposing surfaces.

[33] A correct idea may be formed of the arrangement of the pericardium around the heart by recalling how a boy puts on and wears his toboggan cap. The pericardium encloses the heart exactly as this cap covers the boy’s head.

[34] “Alcohol taken in small and single doses, acts almost exclusively on the brain and the blood-vessels of the brain, whereas taken in large and repeated doses its chief effects are always nervous effects. The first effects of alcohol on the function of inhibition are to paralyze the controlling nerves, so that the blood-centers are dilated, and more blood is let into the brain. In consequence of this flushing of the brain, its nerve centers are asked to do more work.”—Dr. T. S. Clouston, Medical Superintendent of the Royal Asylum, Edinburgh. “Alcoholic drinks prevent the natural changes going on in the blood, and obstruct the nutritive and reparative functions.”—Professor E. L. Youmans, well-known scientist and author of _Class Book of Chemistry_.

[35] The word “cell” is not used in this connection in its technical signification of a histological unit of the body (sec. 12), but merely in its primary sense of a small cavity.

[36] “The student must guard himself against the idea that arterial blood contains no carbonic acid, and venous blood no oxygen. In passing through the lungs venous blood loses only a part of its carbonic acid; and arterial blood, in passing through the tissues, loses only a part of its oxygen. In blood, however venous, there is in health always some oxygen; and in even the brightest arterial blood there is actually more carbonic acid than oxygen.”—T. H. Huxley.

[37] “Consumption is a disease which can be taken from others, and is not simply caused by colds. A cold may make it easier to take the disease. It is usually caused by germs which enter the body with the air breathed. The matter which consumptives cough or spit up contains these germs in great numbers—frequently millions are discharged in a single day. This matter spit upon the floor, wall, or elsewhere is apt to dry, become pulverized, and float in the air as dust. The dust contains the germs, and thus they enter the body with the air breathed. The breath of a consumptive does not contain the germs and will not produce the disease. A well person catches the disease from a consumptive only by in some way taking in the matter coughed up by the consumptive.”—Extract from a circular issued by the Board of Health of New York City.

[38] “The lungs from the congested state of their vessels produced by alcohol are more subject to the influence of cold, the result being frequent attacks of bronchitis. It has been recognized of late years that there is a peculiar form of consumption of the lungs which is very rapidly fatal and found only in alcohol drinkers.”—Professor H. Newell Martin.

[39] “The relation to Bright’s Disease is not so clearly made out as is assumed by some writers, though I must confess to myself sharing the popular belief that alcohol is one among its most important factors.”—Robert T. Edes, M.D.

[40] Thus the fibers which pass out from the sacral plexus in the loins, and extend by means of the great sciatic nerve and its branches to the ends of the toes, may be more than a yard long.

[41] Remarkable instances are cited to illustrate the imperative demand for sleep. Gunner boys have been known to fall asleep during the height of a naval battle, owing to the fatigue occasioned by the arduous labor in carrying ammunition for the gunner. A case is reported of a captain of a British frigate who fell asleep and remained so for two hours beside one of the largest guns of his vessel, the gun being served vigorously all the time. Whole companies of men have been known to sleep while on the march during an arduous campaign. Cavalrymen and frontiersmen have slept soundly in the saddle during the exhausting campaigns against the Indians.

[42] According to the Annual Report of New York State Reformatory, for 1896, drunkenness among the inmates can be clearly traced to no less than 38 per cent of the fathers and mothers only. Drunkenness among the parents of 38 per cent of the prisoners in a reformatory of this kind is a high and a serious percentage. It shows that the demoralizing influence of drink is apt to destroy the future of the child as well as the character of the parent. “There is a marked tendency in nature to transmit all diseased conditions. Thus the children of consumptive parents are apt to be consumptive. But, of all agents, alcohol is the most potent in establishing a heredity that exhibits itself in the destruction of mind and body. There is not only a propensity transmitted, but an actual disease of the nervous system.”—Dr. Willard Parker.

[43] “It is very certain that many infants annually perish from this single cause.”—Reese’s _Manual of Toxicology_.

[44] If an eye removed from its socket be stripped posteriorly of the sclerotic coat, an inverted image or the field of view will be seen on the retina; but if the lens or other part of the refractive media be removed, the image will become blurred or disappear altogether.

[45] This change in the convexity of the lens is only a slight one, as the difference in the focal point between rays from an object twenty feet distant and one four inches distant is only one-tenth of an inch. While this muscular action is taking place, the pupil contracts and the eyeballs converge by the action of the internal rectus muscles. These three acts are due to the third nerve (the motor oculi). This is necessary in order that each part should he imprinted on the same portion of the retina, otherwise there would be double vision.

[46] The Germans have a quaint proverb that one should never rub his eyes, except with his elbows!

[47] “The deleterious effect of tobacco upon eyesight is an acknowledged fact. The Belgian government instituted an investigation into the cause of the prevalence of color-blindness. The unanimous verdict of the experts making the examination was that the use of tobacco was one of the principal causes of this defect of vision. “The dimness of sight caused by alcohol or tobacco has long been clinically recognized, although not until recently accurately understood. The main facts can now be stated with much assurance, since the publication of an article by Uhthoff which leaves little more to be said. He examined one thousand patients who were detained in hospital because of alcoholic excess, and out of these found a total of eye diseases of about thirty per cent. “Commonly both eyes are affected, and the progress of the disease is slow, both in culmination and in recovery.... Treatment demands entire abstinence.”—Henry D. Noyes, Professor of Otology in the Bellevue Hospital Medical College, New York.

[48] “The student who will take a little trouble in noticing the ears of the persons whom he meets from day to day will be greatly interested and surprised to see how much the auricle varies. It may be a thick and clumsy ear or a beautifully delicate one; long and narrow or short and broad, may have a neatly formed and distinct lobule, or one that is heavy, ungainly, and united to the cheek so as hardly to form a separate part of the auricle, may hug the head closely or flare outward so as to form almost two wings to the head. In art, and especially in medallion portraits, in which the ear is a marked (because central) feature, the auricle is of great importance”—William W. Keen, M.D., editor of Gray’s _Anatomy_.

[49] The organ of Corti is a very complicated structure which it is needless to describe in this connection. It consists essentially of modified ephithelial cells floated upon the auditory epithelium, or basilar membrane, of the cochlea. There is a series of fibers, each made of two parts sloped against each other like the rafters of a roof. It is estimated that there are no less than 3000 of these arches in the human ear, placed side by side in a continuous series along the whole length of the basilar membrane. Resting on these arches are numbers of conical epithelial cells, from the free surface of which bundles of stiff hairs (cilia) project. The fact that these hair-cells are connected with the fibers of the cochlear division of the auditory nerve suggests that they must play an important part in auditory sensation.

[50] The voices of boys “break,” or “change,” because of the sudden growth or enlargement of the larynx, and consequent increase in length of the vocal cords, at from fourteen to sixteen years of age. No such enlargement takes place in the larynxes of girls: therefore their voices undergo no such sudden change.

[51] This experiment and several others in this book, are taken from Professor Bowditch’s little book called _Hints for Teachers of Physiology_, a work which should be mastered by every teacher of physiology in higher schools.

[52] The teacher or student who is disposed to study the subject more thoroughly and in more detail than is possible in a class text-book, will find all that is needed in the following excellent books, which are readily obtained by purchase, or may be found in the public libraries of larger towns: Dulles’ _Accidents and Emergencies;_ Pilcher’s _First Aid in Illness and Injury_; Doty’s _Prompt Aid to the Injured;_ and Johnston’s “Surgical Injuries and Surgical Diseases,” a special article in Roosevelt’s _In Sickness and in Health_.

[53] “A tourniquet is a bandage, handkerchief, or strap of webbing, into the middle of which a stone, a potato, a small block of wood, or any hard, smooth body is tied. The band is tied loosely about the limb, the hard body is held over the artery to be constricted, and a stick is inserted beneath the band on the opposite side of the limb and used to twist the band in such a way that the limb is tightly constricted thereby, and the hard body thus made to compress the artery (Fig. 160). “The entire circumference of the limb may be constricted by any sort of elastic band or rubber tube, or any other strong elastic material passed around the limb several times on a stretch, drawn tight and tied in a knot. In this way, bleeding may be stopped at once from the largest arteries. The longer and softer the tube the better. It requires no skill and but little knowledge of anatomy to apply it efficiently.” Alexander B. Johnson, Surgeon to Roosevelt Hospital, New York City.

[54] Corrosive sublimate is probably the most powerful disinfectant known. A solution of one part in 2000 will destroy microscopic organisms. Two teaspoonfuls of this substance will make a solution strong enough to kill all disease germs.

[55] The burning of sulphur produces sulphurous acid, which is an irrespirable gas. The person who lights the sulphur must, therefore, immediately leave the room, and after the lapse of the proper time, must hold his breath as he enters the room to open the windows and let out the gas. After fumigation, plastered walls should be white-washed, the woodwork well scrubbed with carbolic soap, and painted portions repainted.

[56] Put copperas in a pail of water, in such quantity that some may constantly remain undissolved at the bottom. This makes a saturated solution. To every privy or water-closet, allow one pint of the solution for every four persons when cholera is about. To keep privies from being offensive, pour one pint into each seat, night and morning.

[57] “While physiology is one of the biological sciences, it should be clearly recognized that it is not, like botany or zoology, a science of observation and description; but rather, like physics or chemistry, a science of experiment. While the amount of experimental instruction (not involving vivisection or experiment otherwise unsuitable) that may with propriety be given in the high school is neither small nor unimportant, the limitations to such experimental teaching, both as to kind and as to amount, are plainly indicated. “The obvious limitations to experimental work in physiology in the high school, already referred to, make it necessary for the student to acquire much of the desired knowledge from the text-book only. Nevertheless, much may be done by a thoughtful and ingenious teacher to make such knowledge real, by the aid of suitable practical exercises and demonstrations.”—_Report of the Committee of Ten on Secondary School Studies_.

[58] This ingenious and excellent experiment is taken from the _New York School Journal_ for May, 1897, for which paper it was prepared by Charles D. Nason, of Philadelphia.