A manual of percussion and auscultation

Preface

This work contains the substance of the lessons which the author has for many years given, in connection with practical instruction in percussion and auscultation, to private classes composed of medical students and practitioners.

In his courses of practical instruction, his plan has been, 1st. To simplify the subject as much as possible, avoiding all needless refinements ; 2d. To consider the distinctive characters of the different physical signs as determined, not by analogies, nor by deductions from physics, but by analysis, and as based especially on variations in the intensity, pitch, and quality of sounds ; 3d. To impress the fact that the significance of physical signs relates to certain physical conditions, and the importance of a familiar acquaintance with these conditions, as well as with the distinctive characters of the signs by which they are represented • 4th. To enforce the necessity of sufficient study of the physical conditions and the signs of health, as a sine qua non for success in the study of the physical diagnosis of diseases ;

IV PREFACE.

and, 5th. To waive discussion of the mechanism of signs, whenever this is open for discussion, taking the ground that our knowledge of the significance of signs rests solely on the constancy of their connection with the physical conditions which they represent.

This* plan has been pursued in writing the book, which the author hopes may be found useful, not only to medical students engaged in the practical study of percussion and auscultation, but, as a handbook for reference, to the practitioner of medicine.

New York, June, 1876.

Introduction

PAGE

Definition of percussion and auscultation — The sounds obtained by these methods representing healthy and morbid physical conditions — Definition of signs — The basis of our knowledge of signs the constancy of association of certain sounds with certain physical conditions in health and disease — The present state of perfection of our knowledge of signs furnished by percussion and auscultation — Requirements for the successful study of these methods of exploration — The anatomy and physiology of the chest — An enumeration of the points relating thereto which are of especial importance — The physical conditions incident to the different diseases of the chest : the conditions relating to the respiratory system stated, and a summary of them — The distinctive characters of healthy and morbid signs; variations in intensity, pitch, and quality, considered as the chief source of the characters distinguishing the signs of disease from each other and from those of health — Other distinctions than those of intensity, pitch, and quality — The analytical method of the study of percussion and auscultation — The significance of the signs as regards the physical conditions which they severally represent — Morbid conditions, not individual diseases, represented by the morbid signs — Regional divisions of the chest — Anatomical relations of the regions severally to the parts within the chest . . 13

Chapter II. Percussion In Health

Percussion with the fingers or with a percussor and pleximeter — The normal vesicular resonance on percussion ; its distinctive characters relating to intensity, pitch, and quality — Variations in the characters of the normal vesicular resonance in different persons

1*

VI CONTENTS

— Relations of the pitch of resonance to the vesicular quality — Tympanitic resonance over the abdomen — Variations of the normal resonance in the different regions of the chest — Enumeration of the regions in which the resonance on the two sides varies, and those in which it is identical in health — Influence of age on the normal resonance — Influence of the acts of respiration on the resonance — Rules in the practice of percussion .... 40

Chapter III. Percussion In Disease

Enumeration of the signs of disease furnished by percussion — Requirements for a practical knowledge of these signs — The distinctive characters of, the morbid physical conditions represented by, and the different diseases into the diagnosis of which enter, these signs, severally, to wit, 1. Absence of resonance or flatness; 2. Diminished resonance ordulness; 3. Tympanitic resonance; 4. Vesiculo-tympanitic resonance; 5. Amphoric resonance; 6. Cracked metal resonance — Sense of resistance felt in the practice of percussion as a morbid sign . . . . . . .58

Chapter IV. Auscultation In Health

Importance of the study of the auscultatory sounds in health — Immediate and mediate auscultation — Advantages of the binaural stethoscope — Rules to be observed in auscultation — Divisions of the study of auscultation in health — The normal laryngeal and tracheal respiration — The normal vesicular murmur; its distinctive characters ; and the variations in the different regions on the same side, and in corresponding regions on the two sides of the chest — The normal vocal resonance — The laryngeal and tracheal voice and whisper — The normal thoracic vocal resonance and fremitus ; the distinctive characters of each ; the variations in different regions on the same side, and in corresponding regions on the two sides of the chest — The normal bronchial whisper, with its variations in different regions on the same side, and in corresponding regions on the two sides of the chest ....

CONTENTS. Vll

Chapter V. Auscultation Iis" Disease

PAGE

The respiratory signs of disease : — Abnormal modifications of the normal respiratory sounds : — Increased vesicular murmur — Diminished vesicular murmur — Suppressed respiratory sound — Bronchial or tubular respiration — Broncho-vesicular respiration — Cavernous respiration — Broncho-cavernous respiration — Amphoric respiration — Shortened inspiration — Prolonged expiration — Interrupted respiration. Adventitious respiratory sounds or rales : — Laryngeal and tracheal rales — Moist bronchial rales, coarse, fine, and subcrepitant — Vesicular or crepitant rale — Cavernous or gurgling rale — Pleural friction rales, metallic tinkling and splashing. Indeterminate rales — The vocal signs of disease : — Bronchophony — Whispering bronchophony — 2Egophony — Increased vocal resonance — Increased bronchial whisper — Cavernous whisper — Pectoriloquy — Amphoric voice or echo — Diminished and suppressed vocal resonance — Diminished and suppressed vocal fremitis — Metallic tinkling. Signs obtained by acts of coughing or tussive signs . . . . . . .90

Chapter VI. The Physical Diagnosis Of Diseases Of The Respiratory

SYSTEM.

Affections of the larynx and trachea — Bronchitis seated in large bronchial tubes — Bronchitis seated in small bronchial tubes, or capillary bronchitis — Collapse of pulmonary lobules — Lobular pneumonia — Asthma — Pulmonary or vesicular emphysema — Pleurisy, acute and chronic — Empyema — Hydrothorax — Pneumothorax — Pneumo-hydrothorax — Acute lobar pneumonia — Circumscribed pneumonia — Embolic pneumonia — Hemorrhagic infarctus — Pulmonary apoplexy — Pulmonary gangrene — Pulmonary oedema — Carcinoma of lung — Tumor within the chest — Acute miliary tuberculosis — Phthisis — Eibroid phthisis — Interstitial pneumonia or cirrhosis of lung — Diaphragmatic hernia ..... 143

Chapter VII

THE PHYSICAL CONDITIONS OF THE HEART IN HEALTH AND DISEASE. THE HEART SOUNDS AND CARDIAC MURMURS.

Physical conditions of the heart in health : — Boundaries of the praecordia — Normal situation of the apex-beat — Boundaries of

V1U CONTENTS.

the deep and of the superficial cardiac space — Relations of the aorta and the pulmonary aitery to the walls of the chest — The heart-sounds — Characters distinguishing the first and the second sound — Mechanism of the production of the heart-sounds — Auscultation of the pulmonic and the aortic second sound separately — Movements of the auricles and ventricles in relation to each other — Physical conditions of the heart in disease : — Enlargement of the heart — Hypertrophy and dilatation — Abnormal impulses of the heart, and modifications of the apex-heat — Valvular lesions — Roughness of the pericardial surfaces — Liquid within the pericardial sac — Abnormal modifications of the heart-sounds — Reduplication of heart-sounds — Cardiac murmurs — Normal and abnormal blood-currents within the heart, and their relations with the heart-sounds — Mitral direct murmur — Mitral regurgitant murmur — Mitral systolic non-regurgitant, or intra-ventricular murmur — Aortic direct murmur — Aortic regurgitant murmur, and an aortic diastolic non-regurgitant murmur — Coexisting endocardial murmurs — Tricuspid direct murmur — Tricuspid regurgitant murmur — Pulmonic direct murmur — Pulmonic regurgitant murmur — Facts of practical importance in relation to endocardial murmurs — Pericardial or friction murmur ........... 191

Chapter VIII

THE PHYSICAL DIAGNOSIS OF DISEASES OP THE HEART AKD OF THORACIC ANEURISM.

Enlargement of the heart by hypertrophy and dilatation — Valvular lesions, mitral, aortic, tricuspid, and pulmonic — Fatty degeneration and softening of the heart — Endocarditis — Pericarditis — Functional disorders — Thoracic aneurism ..... 229

MANUAL

OF

PERCUSSION AND AUSCULTATION,

Chapter I Introduction

Definition of percussion and auscultation — The sounds obtained by these methods representing healthy and morbid physical conditions — Definition of signs — The basis of our knowledge of signs the constancy of association of certain sounds with certain physical conditions in health and disease — The present state of perfection of our knowledge of signs furnished by percussion and auscultation — Requirements for the successful study of these methods of exploration — The anatomy and physiology of the chest — An enumeration of the points relating thereto which are of especial importance — The physical conditions incident to the different diseases of the chest ; the conditions relating to the respiratory system stated, and a summary of them— The distinctive characters of healthy and morbid signs ; variations in intensity, pitch, and quality, considered as the chief source of the characters distinguishing the signs of disease from each other and from those of health — Other distinctions than those of intensity, pitch, and quality — The analytical method of the study of percussion and auscultation — The significance of the signs as regards the physical conditions which they severally represent — Morbid conditions, not individual diseases, represented by the morbid signs — Regional divisions of the chest — Anatomical relations of the regions severally to the parts within the chest.

Physical Exploration.

The physical exploration of the chest embraces six different methods, namely : percussion, auscultation, inspection, palpation, mensuration, and succussion. Of these, percussion and auscultation, dealing with sounds, involve the sense of hearing. In percussion, the sounds are produced by striking upon the walls of the chest; in auscultation, they are caused by acts of breathing, speaking, and coughing.

The sounds in percussion and auscultation are, 1st, normal or healthy sounds, being produced when there is no disease of the chest; and, 2d, abnormal or morbid sounds, being produced when the chest is the seat of disease. The sounds, healthy and morbid, constitute what are known as physical signs. Frequently, for the sake of brevity, the term signs, without the word physical, is used to denote these sounds. Conventionally, physical signs, or signs, are terms employed in a sense of contradistinction from the term symptoms. The signs are distinguished, of course, as normal or healthy and abnormal or morbid.

The sounds which constitute signs represent certain physical conditions pertaining to the chest. The normal or healthy signs represent physical conditions existing when the organs are not affected by disease; the abnormal or morbid signs represent physical conditions which are deviations from, those of health, being incident to the various diseases of the chest. The physical conditions represented by signs may be distinguished as normal or healthy, and abnormal or morbid conditions.

The representation of healthy and morbid physical conditions by certain healthy and morbid signs is established by having ascertained a constancy of association. of the signs with the conditions. This constancy of association is ascertained by observation or experience. The sounds which are constantly

PHYSICAL EXPLORATION. 15

obtained by percussion and auscultation in health are thereby established signs of healthy conditions, and the sounds which are only obtained in cases of disease are thereby established signs of morbid conditions. Our knowledge of certain sounds as the signs of certain physical conditions can have no reliable basis other than the constancy of the connection of the former with the latter. This constancy of connection is determined by the study of the sounds during life and examination of the organs after death. The existence of certain conditions is not to be inferred from the characters of certain sounds until the connection of the sounds with the conditions has been ascertained by experience ; then, and then only, are the sounds to be reckoned as signs of these conditions. So, also, it is not to be inferred from certain physical conditions found after death, that certain sounds must have been produced during life, until the connection between the conditions and the sounds has been ascertained by experience. In other words, our knowledge of signs as representing physical conditions, can rest on no other than a purely empirical foundation.

Our knowledge of the signs representing the physical conditions in health and disease, thanks to the labors of Laennec and of those who have followed in his footsteps, has been brought to great perfection. The practical object of this knowledge is to determine by means of percussion and auscultation, together with the other methods of exploration, the existence of either healthy or morbid physical conditions, and to discriminate the latter from eacli other ; that is to say, the practical object is diagnosis. The signs now known to represent physical conditions, healthy and morbid, taken in connection with symptoms and pathological laws, render, for the most part, the diagnosis of diseases of the chest easy and positive. Hence, it becomes the duty of the medical student and practitioner to give to percussion and auscultation attention sufficient, at least, for their practical application to the diagnosis of the diseases commonly met with in medical practice ; and this duty is the more imperative because it involves neither peculiar difficulties nor great labor. In entering upon the undertaking, it is important to consider the requirements for the successful study of this province of practical medicine. These requirements relate to: 1st, the anatomy and physiology of the chest; 2d, the morbid physical conditions incident to the different diseases of the chest ; 3d, the distinctive characters of healthy and morbid signs ; and 4th, the significance of the signs as regards the physical conditions which they severally represent.

Anatomy and Physiology of the Chest.

The necessity of a certain amount of knowledge of the anatomy and physiology of the chest, as a requirement for the study of percussion and auscultation, together with the other methods of physical exploration, is too obvious to need any discussion. The physical conditions of health must be known as preparatory for appreciating the physical conditions of disease. It would be absurd to think of studying the latter until the former are known. The student, therefore, who is not acquainted with the anatomy and physiology of the chest, must defer

ANATOMY AND PHYSIOLOGY OF CHEST. 17

entering upon the study of physical diagnosis until this requirement is fulfilled. Familiarity with the morbid physical conditions is necessary ; and for the advanced medical student or the practitioner, it is advisable to refresh the memory with a reviewal of certain anatomical and physiological points before beginning the study of percussion and auscultation. These points, relating especially to the physical conditions of health, cannot be considered in this work. A simple enumeration of them can only be introduced, the reader being referred for details to treatises on anatomy and physiology.

Important anatomical conditions relate to the bones of the chest, namely, the general conformation of the thorax ; the differences in respect of the obliquity of the ribs, from above downward ; the direction of the costal cartilages, their connection with the sternum, and the angles formed by the junction of the ribs and cartilages ; the differences in width of the intercostal spaces in the upper, middle, and lower portions of the anterior, lateral, and posterior aspects of the thorax, together with the relations of the scapula and clavicle. The relative thickness of the muscular covering of the chest in different situations is to be considered, and, in women, the varying size of the mammas. The attachments of the diaphragm to the thoracic walls, and its relations to the organs below, as well as above it, are points of importance.

Important physiological conditions relate to the parts which the ribs, costal cartilages, sternum, and diaphragm severally play in the movements of respiration. The differences, in respect of these move-

9* ments, in tranquil and in forced breathing; the contrast between the two sexes, and between early and advanced life are points to be studied. Other points are, the frequency of the respiration in health, and the relative duration, rapidity, and force of the inspiratory and the expiratory movements.

Numerous anatomical and physiological points pertain to the organs within the chest. The more important of these, relating to normal physical conditions, are the following: 1st, as regards the lungs, the connections of the pleura, and the smoothness of the pleural surfaces in contact with each other ; the relations of the apex and base of each lung to the chest-walls, and the differences of the two lungs in this respect ; the relative spaces occupied respectively by the two lobes of the left, and the three lobes of the right lung ; the situation of the interlobar fissures in either side on the posterior, lateral, and anterior aspects of the chest ; the arrangement of the air vesicles, pulmonary lobules, and the different sized intra-pulmonary bronchial tubes; the expansion of the air vesicles, and the movement of the current of air from larger to smaller bronchial tubes in the act of inspiration, the vesicles diminishing: in size, and the current of air moving from smaller to larger tubes in the act of expiration; the difference in respect of the relative proportion of air and solids at the end of inspiration and at the end of expiration; the extent to which the volume of the lungs may be diminished by a forced act of expiration, and increased by a forced act of inspiration ; the relations of the apices to the subclavian arteries, and the variable extent to which the apex

ANATOMY AND PHYSIOLOGY OF CHEST. 19

rises on either side above the clavicle. 2d, as regards the larynx, trachea, and the bronchial tubes without the lungs, the anatomy and physiology of the vocal chords, of the muscles concerned in the movements of respiration and of phonation, with the relations of each to the recurrent laryngeal nerve; the size of the rima glottidis in youth, after puberty, and relatively in the two sexes; the difference in the amount of areolar tissue above the vocal chords in children and in adults; the situation of the trachea, and the point of its bifurcation ; the length, direction, and size of the two primary bronchi contrasted with each other, and the secondary branches which penetrate the lungs. 3d, as regards the heart, the boundaries of the space which it occupies — that is, of the precordial space ; the relations of the aorta and pulmonic artery to the walls of the chest, the portions of the precordial space in which the heart is covered and uncovered by lung; the situations of the auricles and ventricles respectively ; the relations of these to each other, and the arrangements of the valves ; the currents of blood through the orifices within the heart, and the relations of each of these to the heart-sounds ; the rhythmical succession of these sounds, and the differences which distinguish each from the other in respect of loudness, duration, tone, quality, extent of diffusion, and the situation in which each has its maximum of intensity; the mechanism of these sounds, and the situation of the apex-beat.

The foregoing are the anatomical and physiological points which especially claim attention with reference to normal physical conditions preparatory to entering on the study of abnormal physical conditions represented by the signs furnished by percussion and auscultation, together with the other methods of physical exploration.

The Physical Conditions Incident to the Different Diseases of the Respiratory System.

The numerous physical conditions incident to different diseases must be known, for it is the immediate object of percussion, auscultation, and the other methods of exploration, to ascertain either the existence or the absence of these conditions. Knowledge of all the important conditions which are deviations from those of health, and the relations of each to different diseases, is, therefore, an essential requirement.

Deviations from the normal conformation of the chest, and the various abnormal movements of respiration, belong properly among the physical signs obtained by inspection, palpation, and mensuration. For the most part, these signs represent morbid physical conditions within the chest. Certain conditions relating to the pleura are accumulations of liquid, serous or purulent, within the pleural sac. The quantity of liquid may be large enough to compress the lung into a solid mass, and to enlarge the affected side, at the same time restraining or annulling the respiratory movements ; the chest on the affected side, then, will contain only lung solidified by compression and liquid. In other cases the quantity of liquid is either small, moderate, or considerable, the lung, then, containing a lessened quan-

DISEASES OF RESPIRATORY SYSTEM. 21

tity of air, and its volume diminished in proportion to the amount of liquid. These conditions are incident to simple pleurisy with effusion, pyothorax or empyema, and hydrothorax.

The pleural surfaces, in cases of pleurisy, may be more or less covered with recent lymph, and, when not separated by the presence of liquid, they do not move upon each other smoothly and noiselessly. The friction of the opposed surfaces is still more productive of audible and sometimes tactile signs after the absorption of liquid, when the exuded lymph has become more adherent and dense than when it is recent.

The presence of air in the pleural space, either alone or with more or less liquid, in pneumothorax, may compress the lung into a solid mass, also dilating the affected side, and restraining or annulling its movements; and the air, with or without liquid, when not in sufficient quantity to produce these effects, may diminish more or less the volume of the lung and the amount of air in the pulmonary vesicles. These conditions give rise to characteristic physical signs. The perforation of lung, usually existing in cases of pneumothorax, occasions additional signs which are characteristic.

Solidification of lung is an important physical condition incident to several diseases, irrespective of the condensation just referred to caused by the compression of liquid or air in the pleural sac. Complete consolidation of an entire lobe, or of two and even three lobes, exists in the second stage of lobar pneumonia. Certain physical signs are found to represent this condition of complete solidification. The different degrees of solidification, namely, slight, moderate, and considerable, occur during the stage of resolution in cases of pneumonia, and these gradations are severally represented by well-defined characters pertaining to physical signs. Solidification, circumscribed, forming nodules which vary in degree and in the extent of June: affected, occurring either in one situation or more or less numerous, situated in the upper, lower, or middle portion of the lung, either on one side or on both sides, exists in phthisis, in broncho-pneumonia or collapse of pulmonary lobules, in hydatids, in hemorrhagic infarctus or embolic pneumonia, in pulmonary gangrene, and in carcinoma. It exists, greater or less in degree and more or less extended, in interstitial pneumonia. In these different connections the existence of solidification, its degree and extent, its limitation to one situation or its existence at different points, are determinable by means of physical signs.

A physical condition the opposite of solidification is an abnormal accumulation of air within the air vesicles of the lungs. This is incident to pulmonary or vesicular emphysema, arising from a morbid dilatation of the air vesicles. The permanent expansion and increased volume of the upper lobes in some cases of this disease, occasion a characteristic deformity of the chest, together with certain deviations from the normal movements of respiration, which are also characteristic. This condition is represented by distinctive signs furnished by percussion and auscultation. Interstitial emphysema, that is, the extravasation of air in the areolar tissue, or inter-

DISEASES OF EESPIEATOEY SYSTEM. 23

lobular emphysema, in like manner gives rise to signs furnished by these methods of exploration.

The presence of a viscid exudation within the air vesicles and bronchioles, is a morbid physical condition incideut to vesicular pneumonia, especially in its first stas;e, ao-o'lutinatino- the walls of the cells and bronchioles, which may be brought into contact or close proximity at the end of the act of expiration. The separation of the walls thus agglutinated, in the act of inspiration, gives rise to an auscultatory sign (the crepitant rale) which is diagnostic of vesicular, in distinction from interstitial, pneumonia, known also as lobar and croupous pneumonia.

An accumulation of serum within the air vesicles constitutes the condition called pulmonary oedema. This condition gives rise to signs furnished by percussion and auscultation.

Liquid within the bronchial tubes (serum, pus, blood, or thin mucus) is a condition incident to pulmonary oedema, abscess either of the lung or situated elsewhere and evacuating through the bronchial tubes, phthisis, bronchorrhagia,pneumorrhagia, bronchorrhcea, and bronchitis. The passage of air through the different varieties of liquid in the tubes, causes bubbling sounds which are appreciable in auscultation. The apparent size of the bubbles (coarseness or fineness) denotes the size of the tubes in which they are produced, and the pitch of the bubbling sounds denotes either solidification or otherwise of the pulmonary substance surrounding the tubes in which the bubbles are produced. Bubbling sounds more intense and on a larger scale are caused by the presence of liquid within the trachea and larynx, known as the tracheal rales or the death rattle.

Diminished calibre of the bronchial tubes within the lungs, either localized, or diffused, is a condition due to the presence of tenacious mucus, and the swelling of the mucous membrane in cases of bronchitis. In cases of so-called capillary bronchitis the condition may involve an alarming degree of obstruction. The same condition is incident to bronchial spasm in asthma, occasioning in this disease great suffering, but without immediate danger. The condition is represented by auscultatory signs which enable the auscultator to differentiate the obstruction due to capillary bronchitis from that due to bronchial spasm. Permanent obliteration of more or less of the bronchial tubes is an occasional condition.

Obstruction of a bronchial tube, either within or without the lung, is a condition involving the loss of respiratory sound within the area of the bronchial branches and vesicles not receiving air in consequence of the obstruction. The obstruction may be temporary, being caused by a plug of mucus of sufficient size to prevent the passage of air ; the condition is then incident to bronchitis. One of the primary bronchi may be obstructed temporarily by a plug of mucus ; and obstruction of the larynx in childhood thus produced may be sufficient to cause death by suffocation. The inhalation of foreign bodies is another cause of obstruction within the larynx, trachea, or bronchi. A primary bronchus or the trachea may be pressed upon by an aneurismal or other tumor, and, in this way, more or less obstruc-

DISEASES OF RESPIRATORY SYSTEM. 25

tion to the passage of air is produced. However produced, the situation of the obstruction and its degree are, in general, determinable by means of auscultatory signs.

Dilatation of bronchial tubes occasions two physical conditions differing as regards their auscultatory signs, namely, 1st, an enlargement of greater or less extent, the tubes preserving their cylindrical form; and 2d, a sacculated enlargement. The former occurs generally in connection with solidification around the tubes from hyperplasia of the areolar tissue, and is thus incident to interstitial pneumonia. The latter may give rise to signs which represent, pulmonary cavities.

Sacculated dilatations of bronchial tubes, and the cavities incident to phthisis, pulmonary abscess, and circumscribed gangrene of lung, are represented by well-marked and highly distinctive signs furnished by percussion and auscultation. The signs denote either that cavities have flaccid walls which collapse in expiration, and expand in inspiration, or that, owing to solidification of lung, they remain open in both acts of respiration.

More or less of the space within the chest, which, normally, is occupied by lung, may be encroached upon by aneurisms or other intra-thoracic tumors. This is a physical condition giving rise to notably morbid signs furnished by percussion and auscultation.

Finally, an extremely rare morbid physical condition is the presence of more or less of the hollow viscera of the abdomen within the chest, in consequence of a congenital deficiency in the diaphragm, constituting diaphragmatic hernia.

The foregoing morbid physical conditions relate to the respiratory system. Those relating to the heart are deferred, in order that they may precede more immediately an account of the signs of cardiac disease. As a requirement for the study of morbid physical signs, the foregoing morbid physical conditions must be understood and memorized. To assist the student in the latter, a summary of these conditions is appended.

Summary of Morbid Physical Conditions Incident to Diseases of the Respiratory System.

1. An accumulation of liquid, serous or purulent, sufficient to fill the affected side of the chest, and sometimes causing more or less enlargement.

2. An accumulation of liquid partially filling the affected side of the chest, the quantity being either small, moderate, or considerable.

3. Exudation of lymph on the pleural surface.

4. Air with liquid within the pleural cavity, and perforation of lung.

5. Air without liquid in the pleural cavity, and perforation.

6. Solidification of lung, either complete or approximating to completeness.

7. Solidification of lung slight or moderate in degree.

8. Dilatation of the air vesicles involving within them an abnormal accumulation of air.

9. Extravasation of air within the pulmonary areolar structure.

HEALTHY AND MORBID SIGNS. 27

10. Viscid exudation within the air vesicles and the "bronchioles.

11. Liquid in the air vesicles.

12. Liquid (mucus, serum pus, or blood) within bronchial tubes of large, medium, or small size.