STANDARD MEDICAL PUBLICATIONS WM. T. COI.LIER. 43CUV Bank Buililin^'. Buffalo. N. \ GLP I Z( Coluttrfjia ®mbersittp CoUege of S^f)psiitiansi anb ^uvQtoni 33r. Halter K5. f ameg Respiratory Exercises TREATMENT OF DISEASE. XOTAnLV OF THE HEART, LUNGS, MiRlOi'S AXn DH.ESTIl'E SYSTEMS. KY HARRY CAxMPBELL, M.D., B.S., Loxd. Fellow of the Royal College of Physicians. Londo.n, Physician to the Xorth-west 1,o.vdon Hospit.^l, a>jd to Hospital fok diseases OF the Nervous System, Welbeck Street. NEW YORK : WILLIAM WOOD AND COMPANY. MDCCCXCIX. G PREFACE By modifying the respiratory movements in certain ways we can produce profound effects upon the organism. Not only can we regulate the absorption of oxygen and the elimina- tion of the respiratory excreta, but we can also influence the circulation of blood and lymph, both generally and locally. Now, it occurred to me that some of these effects might be useful in the treatment of disease, and after prolonged and careful investigation I have come to the conclusion that properly-devised respiratory exercises have a great therapeutical value. This mode of treatment being founded on physiological principles, it has been necessary to define those principles, and this has involved a somewhat severely technical exposition. Those who have not the leisure nor the inclination to study this portion of the book may proceed at once to the more practical portion of it, beginning at Chapter XX. The present work is the outgrowth of a larger one on the mechanical treatment of heart disease, a subject which has IV PREFACE occupied my thoughts from the very outset of my medical career. It was not until the book was well advanced that I became aware that I had been in a measure forestalled by the physicians of Nauheim. Their therapeutical methods were arrived at empirically ; mine by an application of physiological principles. Each line of investigation has a value of its own ; and just as I have been able to supplement my methods by the empirical methods of Nauheim, so conversely, as I shall hope to show in this and my larger work, the Nauheim methods may be ex- tended and corrected by applying the truths of physiology. HAERY CAMPBELL. 23, WiMPOLE Street, London, W. CONTENTS CHAPTER PAOb I. The Elasticity of the Lungs — Pulmonary Suction ------ 1 MEANS for maintaining PULMONARY elasticity - - - - - 7 II. Intra- Abdominal Tension — Functions of the Abdominal Muscles - - . - 9 secondary effects of low intra- abdominal tension - - - 12 THE action of THE ABDOMINAL MUSCLES - 15 METHOD OF TESTING THE TONE OF THE "^ ABDOMINAL MUSCLES - - - 16 III. The Elasticity of the Thoracic Cage - - 19 IV. The Factors determining the Mean Size of THE Chest - - - - - 25 V. The Mobility of the Thoracic Cage - - 32 means of testing thoracic mobility - 35 VT. The Pleur/E and their Functions — The Move- ments OF the Lungs - - - - 37 the lower limits of the pleura - 38 the movements of the lungs within the chest - - - - - 39 VII, Inspiratory and Expiratory Force - - 43 the breath-force in disease - - 45 RELATIVE strength OF THE INSPIRATORY AND EXPIRATORY MUSCLES - - 46 VI CONTENTS CHAPTER PAGE VIIT. The Eespiratory Forces - - - - 48 IX. Modes in which the Thorax is Enlarged - 54 THE QUANTITY OF AIR THAT CAN BE EXPIRED BY DIFFERENT METHODS OF BREATHING - 60 X. Breathing in Singers - - - - 64 . 1. CLAVICULAR BREATHING - - - 64 2. LOWER COSTAL BREATHING - - - 65 3. LOWER COSTO-ABDOMINAL BREATHING - 66 4. PURE ABDOMINAL BREATHING - - 67 5. ABDOMINO-COSTAL BREATHING = - - 69 XL Vital Capacity - - - - - 75 THE practical VALUE OF GAUGING VITAL CAPACITY : VALUE IN DIAGNOSIS - - 77 THE QUANTITY OF RESIDUAL AIR - - 78 XII. Secondary Effects of the Respiratory Move- ments - - - - - - 79 XIII. Influence of the Eespiratory Movements on THE Circulation of the Blood - - 81 influence of the respiratory movements on arterial and venous tension - 94 influence of the respiratory movements ON the pulse-rate - - - - 97 THE effects of THE RESPIRATORY MOVE- MENTS ON THE CEREBRAL CIRCULATION - 98 XIV. The Influence upon the Circulation, etc., of Modifications in the Density of the Outer Air - 101 the effects of immersing the body in compressed air - - - - 102 the effects of rarefied air - - 102 the effects upon the circulation of varying the density of the air in- spired and expired into, the general atmospheric pressure remaining the SAME - - - - - 103 CONTENTS Vll CHAPTER PAOE XV. Influence of the Rkspiratory Movements on THE Circulation of Lymph - - - 106 XVI. Physiological Modifications in the Respira- tory Movements - - - - 109 diminution in the frequency and depth of the respiratory movements - 110 increased frequency and depth, and altered rhythm from muscle-exercise 111 modifications in the respiratory move- ments leading to augmented intra- pulmonary tension - - - 112 XVII. Normal Modifications of the Respiratory iMovEMENTS {continued) : Talking, Shouting, Singing, Coughing, Crying, Sighing - 117 talking - - - - - 118 shouting - - - - - 121 SINGING - - - - • - 122 laughter - - - - - 125 CRYING - - - - - 125 YAWNING - - - - - 127 XVIII. Impediments to the Respiratory Movements 129 impediments to COSTAL BREATHING - 129 IMPEDIMENTS TO DIAPHRAGMATIC BREATH- ING - - - - - 135 XIX. Hyperoxygenation of the Blood — Dyspn(ea- 140 hyperoxygenation of the blood - 140 dyspnoea - - - - - 142 XX. On THE Various Kinds of Breathing Exercises - - - - - 145 preliminary observations - - 145 preliminary exercises - - - 148 active breathing exercises - - 152 breathing exercises conjoined with active exercises - - - 155 passive respiratory exercises - - 157 exercises for developing the abdo- minal muscles - - - - 160 Vlll CONTENTS CHAPTER PACE XXI. Respiratory Exercises in Diseases of the Lungs ------ 166 as a preventative of pulmonary disease 166 as a means of treating pulmonary DISEASE ----- 168 XXII. Respiratory Exercises in Emphysema - 174 TREATMENT OF EMPHYSEMA - - 181 XXIII. Respiratory Exercises in Heart Disease - 185 XXIV. Respiratory Exercises in the Treatment of Nervous Diseases - - - - 189 XXV. Respiratory Exercises in the Treatment of Digestive Disorders - - - - 192 XXVI. Respiratory Exercises in Other Diseases - 194 gall-stones . - - - 194 obesity ----- 195 anemia - - - - - 195 epistaxis - - - - - 196 stammering - - - - 196 hiccough - - - - - 196 sleeplessness - - - - 196 Index - - - - - - 197 RESPIRATORY EXERCISES IN THE TREATMENT OF DISEASE CHAPTEK L THE ELASTICITY OF THE LUNGS— PULMONARY SUCTION. The lungs occupy that part of the thorax not occupied by the mecliastina, but they are not large enough to fill this space without a considerable stretching of the elastic fibres ■with which they are richly furnished, and hence they are ever tending to contract, this tendency increasing during inspiration and during contraction of the bronchial muscles. The pressure of the atmosphere within them, however, counteracts the tendency, and keeps them closely applied to the chest-walls, heart, aorta, and other contiguous struc- tures. When the chest is opened after death, and the atmosphere allowed to press upon the outside of the lungs as well as from within, they necessarily undergo considerable contraction. Hence, we must think of these organs as ever striving to break away from their surround- ings, and as thus exercismg a negative pressure or suction upon them. We may speak of this as pulmoiiarn siirtioii,^ * Some authors write of the lungs as exercismg traction upon the contiguous structures ; but this is not strictly accurate, inasmuch as 1 is RESPIRATORY EXERCISES and it is owing to it that the pressure in the pleurae and pericardium is negative.* From the foregoing remarks it will be clear that the lungs in no sense suj)port the chest-walls, but, on the contrary, tend to suck them in. It is only towards the end of a deep expiration, or when an expiratory effort is made with closed glottis, that they exert anywhere a positive pressure. In the latter case they may be made to compress the heart and great bloodvessels with such force as actually to stop the circulation. The diaphragm, as the most yielding portion of the chest- wall, is the jDart most influenced by pulmonary suction. The pressure on its abdominal surface is almost always positive. Hence, in its passive state, the diaphragm is sucked upwards into the dome-shaped form, and every contraction and consequent flattening of it has to over- come pulmonary elasticity. When the deepest possible inspiration is taken, the diaphragm tends to be more than usually elevated, owing to the increase in pulmonary suction (see p. 59). The elastic force exerted by the lungs at the end of an ordinary expiration is equal to a column of from 5 to 7 mm. there is no physical union with them. They do indeed drag upon the ^■isceral pleur*, but not upon other parts — the chest-walls, for instance. These latter are not drawn inwards : they are driven inwards, or tend to be so, by the atmospheric pressure, which is greater than the pres- sure which the lungs exert upon the chest-walls. * The negative pressure in the pleurae and pericardium can be estimated by introducing into one of these cavities a cannula con- nected by means of a rigid tube with a manometer, care being taken to exclude the air. It may also be shown that the intra-thoracic portion of the cesophagus is similarly affected by pulmonary suction, and that this increases with every inspiration. Leyden and Quincke have tested the negative pressure in the pleurit after drawing off a pleuritic effusion. The former has shown it to be as low as -42 mm. Hg during a deep inspiration, and the latter as low as - 40 mm. Hg. THE ELASTICITY OF THE LUNGS 3 of mercury, for if after death, when the chest is in a position of ordinary expiration, a manometer is fixed in the trachea the mercury rises to about this height on the chest-walls being punctured and the lungs thus permitted to collapse. When the chest is forcibly inflated to the position of ordinary inspiration, the mercury rises to about 10 mm., and the rise increases to 30 mm. if the chest is distended to the position of extraordinary inspiration. At the end of an extra- ordinary expiration elastic force is absent, the lungs then being actually smaller than after removal from the body. Hence, the elastic force or suction exerted by the lungs under varying degrees of expansion is as follows : At the end of an extraordinary expiration, 0. ,, ,, ordinary ,, 5 mm. Hg. ,, ,, ,, inspiration, 10 ,, ,, ,, extraordinary ,, 30 ,, The elastic force exerted by the bronchial muscles, when contracted, is estimated at from 1 to 2 mm, Hg. Other aspects of pulmonary suction have now to be con- sidered. All the tissues of the body tend to become less elastic with advancing years. It is, for instance, owing to loss of elasticity that the skin becomes wrinkled with age ; it gets permanently stretched, and, no longer tightly adapting itself to the underlying structure, is thrown into folds. As with the skin, so also with the lungs. Their elasticity, and consetjuently the suction they exert, diminishes with ad- vancing years. In the senile lung it is comparatively small. Pulmonary elasticity diminishes much more rapidly in some cases than in others, so that while in one we may find prematurely senile lungs at fifty, in another elasticity may be well preserved at seventy. It may also be diminished by disease. All organic diseases of the lungs — pneumonia, 1—2 4 EESPIRATOEY EXERCISES bronchitis, phthisis — diminish it. In emphysema the dimi- nution is a characteristic feature, and plays a prominent part in its pathology. Elasticity is also probably always diminished in protracted fever ; Cohnheim finds it absent in typhoid ; Perls has fouiid it diminished in typhoid, typhus, and diphtheria ; and both have noticed its loss in phosphorus-poisoning. Undue stretching of the pulmonary alveoli is another very potent cause of its diminution or entire loss. It is in this way that effort, such as coughing and lifting weights, diminishes elasticity. Chronic dyspnoea diminishes it in the same way — namely, by causing overexpansion of the lungs — and hence also the injurious tendency of all exercises causing breathlessness, such as running rapidly upstairs, swimming for a long time under the water, etc. (see pp. 93, 94). It is seldom, however, that pulmonary elasticity is so completely lost as to do away with all suction — in fact, probably in the most advanced cases of emphysema only. When a portion of the lung is solidified, as in pneumonia, it necessarily loses all elasticity, and therefore all suction. Post-mortem examination gives no evidence, however, that the parts thus solidified press upon the chest-walls, as from their distension we might perhaps expect them to do. This is because the thorax over the affected region expands, and I have no doubt that Sir James Douglas-Powell is right in attributing this expansion to loss in pulmonary elasticity. He holds that ' as the inflamed lung increases in bulk, the thoracic wall retreats,' owing to the removal of pul- monary elasticity, which normally causes the ribs to be sucked in Jjeyond the neutral point. ''■ I would suggest that a more important factor even than this is the overaction of the inspiratory muscles. This overaction necessarily results * ' Diseases of tlie Lungs and Pleura;,' 4th edit., p. 19. TEIE ELASTICITY OF THE LUNGS 5 from the diminution of suction, and is, moreover, predisposed to by dyspna'a (see Chapter on Dyspncea). Effusion of gas or liquid into the pleura diminishes pulmonary suction, the stretched elastic fibres of the lung becoming more and more lax as the effusion increases and the lung shrinks, and it continues to diminish until the shrinkage of the lung has proceeded to the point at which the pulmonary fibres are no longer stretched, when it com- pletely disappears. The continuance of effusion beyond this point causes the pressure in the pleura to become increasingly positive. In one case of hydrothorax Ley den found the pressure of the pleural fluid to be 28 mm. Hg, and in a case of pneumothorax he found the pressure of air in the pleura to vary between 5 and 10 mm. Hg. In pleuritic effusion the heart is displaced to the opposite side before the diaphragm is thrust downwards ; for directly the pul- monary suction of the affected side diminishes — and this occurs at the very beginning of the effusion — the heart will be drawn over by the greater suction of the opposite side, but the pressure on the abdominal aspect of the diaphragm being positive, it will not be until the pleural pressure becomes still more positive that the diaphragm will be thrust downwards. Hence, as Douglas-Pow'ell observes, ' displacement downwards of the abdominal viscera is a late phenomenon in pleuritic effusion,'* and 'the stomach note may be obtained at the sixth rib in the nipple line in the presence of a large effusion on that side.' In gaseous effusion into the pleura the heart is imme- diately sucked over to the unaffected side, but the pressure cannot be sufficiently positive to displace the diaphragm until the occurrence of considerable liquid effusion. Just as pulmonary suction diminishes as the elastic fibres of the lungs become more and more lax, so on the other * Oi). cit., p. 106. 6 RESPIRATORY tXERCISES hand, does it increase the more these fibres are stretched, for the greater this stretching, the more do the lungs strive to retract from the chest- wall and other adjacent structures. Hence, suction is greater during inspiration than expiration. The lung presses against its contiguous structures with a force equal to the pressure of the air in the air- vesicles less the amount of elastic force these latter exert upon their contained air. The alveolar air-pressure at the end of an ordinary inspiration is about 1 mm. Hg less than the atmospheric pressure — i.e., 59 mm. Hg — and the alveolar elastic force is then about 10 mm. Hg. Hence, at the end of an ordinary inspiration the lungs jDress upon the surrounding structures with a force equal to 749 mm. Hg, this being 11 mm. Hg less than the atmo- spheric pressure. At the end of an ordinary expiration the alveolar air-pressure is about 2 mm. Hg more than the atmospheric pressure — i.e., 762 mm. Hg — and the alveolar elastic force about 5 mm. Hg. Consequently, the lungs then press upon surrounding structures with a force equal to 762— 5 = 757 mm. Hg, this being 3 mm. Hg less than the atmospheric pressure. It is therefore clear that during ordinary breathing the structures contiguous to the lungs are subject to suction which increases with every inspiration. At the end of an extraordinary inspiration the negative pressure on the extra-pulmonary structures is considerable, while at the termination of an extraordinary c-xpiration the pressure may become very decidedly positive. The effect of vigorous inspiration and expiration is still more pro- nounced when the entrance to the respiratory tract is closed. Thus, a vigorous inspiration with completely closed mouth and nostrils may reduce the pressure to -70 mm. Hg, or further.* This is known as ' Miiller's * According to Ocrtel, it may fall as low as - 100 mm. Hg. (Von Ziemssen's ' Handbook of General Therapeutics,' vol. iii., p. 577). THE ELASTICITY OF THE LUNGS 7 experiment.' The diminution of pressure is essentially due to rarefaction of the intra-pulmonary air, and not simply, as in inspiration with open glottis, to stretching of the elastic lung. On the other hand, a forcible expiration with closed mouth and nostrils, after the method used by aurists to inHate the mid-ear, may raise the intra-pulmonary pressure 120 mm, Hg above that of the atmosphere, the heart and great bloodvessels and intra-pulmonary vessels being in this way so firmly compressed as seriously to interfere with the circulation. This is known as ' Valsalva's experiment.' A similar effect is produced by all forms of effort when a powerful expiration is made with partially or completely closed glottis. The intra-pulmonary air-pressure may in a similar way be modified by causing the air which is inhaled, or that into which the expired air passes, to be condensed or rarefied. Means for maintaining Pulmonary Elasticity. — Since loss of pulmonary elasticity induces many evils, foremost among which is, as we have seen, emphysema, it is of the greatest importance to preserve the elasticity as much as possible. To this end we should endeavour to check the advent of premature senility by urging the individual to lead a healthy, temperate life; the lungs should be carefully protected from bronchitis, pneumonia, and other diseases ; coughing, the blowing of wind instruments, straining at stool, and all other muscle-efforts with fixed thorax, should be avoided ; and special means should be adopted to pre- vent overdistension of the thorax from dyspnoea. The methods given in Chapter XXI. for increasing and pre- serving the mobility of the thoracic cage are also useful in maintaining the elasticity of the lungs. It is by no means impossible to avoid the fixation of the chest which accompanies effort. The fixation is eftected by 8 RESPIRATORY EXERCISES closure of the glottis, and one should therefore get mto the habit of always keeping the glottis open during muscular exertion, for under these circumstances it is impossible to raise the intra-pulmonary pressure unduly, and thus dis- tend the alveoli to a dangerous degree. To take a par- ticular instance : much injury may be done to the lungs by habitual strainmg at stool, but this may be entirely avoided by never allowing the glottis to be closed during defsecation. CHAPTER II. INTRA-ABDOMINAL TENSION— FUNCTIONS OF THE ABDOMINAL MUSCLES. The pressure in the abdominal cavity is under normal con- ditions positive, i.e., greater than the atmospheric pressure, wherefore the abdominal contents press against their con- taining walls, tending to l)ulge them. When, as sometimes happens, the mternal pressure is negative, these walls are sucked in. Positive mtra-abdominal pressure plays a not unimportant part in exph-ation. The diaphragm when in a state of rest lies high, the pressure on its under surface being positive, and that on its upper surface negative. When its muscle- fibres contract, it flattens out, and in so doing it has to work against the intra-abdominal pressure, which it increases. The abdominal viscera constitute, so to speak, an elastic buffer, which is compressed with every descent of the diaphragm, and by its recoil drives the diaphragm up at the end of inspiration. This positive intra-abdominal pressure depends upon the pressure of the atmosphere upon the yielding abdominal walls, and also upon the contraction of the abdominal muscles. Thus, it is greatest in muscular men, while it is least in multiparous women with flaccid abdominal walls. The fact that the abdominal walls are yielding and not rigid, renders it difficult to get a negative intra-abdominal 10 RESPIRATORY EXERCISES pressure, owing to the pressure of the surrounding atmo- sphere. Under certain circumstances, however, it is negative. Thus, when a deep costal inspiration is taken, the diaphragm is sucked upwards by pulmonary suction, and the abdo- minal walls are sucked inwards, this suction being increased if the breath is taken with closed glottis. The effect of this upward movement of the diaphragm upon the pressure within the abdomen is comparable to the pulling out of the piston of an air-pump. It is said that the intra-abdominal tension in some women is habitually negative, a phenomenon very difficult to account for, except on the assumption that it is produced by pulmonary suction. Intra-abdominal tension is increased by forcible con- traction of the abdominal muscles, especially if the glottis is partly or completely closed, as in cough or muscle- effort — straining at stool, for instance. In the latter case the diaphragm is fixed, and the contracting abdominal muscles compress the underlying structures with great force. Inasmuch as intra - abdominal tension is greater in muscular men than in women with flabby abdominal walls, abdominal operations are more difficult in the former than in the latter. In the very muscular the intestines are forcibly driven out directly the cavity is opened, and the hand when introduced may be so firmly grasped as to render exploration of the viscera impossible, without push- ing anaesthesia to its limit.* The degree to which the abdominal muscles compress the underlying viscera is largely determined by occupation. Thus, as Bruce Clarke points out, the abdomen of a fisherman is hard and flat, and may remain so, even up to advanced age, a circumstance he attriljutes mainly to the eft'ect of * See ' On Some Effects of a Lack of Muscular Development,' W. Bruce Clarke, Brit. Med. Jour., 1896, vol. ii., p. 1493. INTRA-ABDOMINAL TENSION 11 rope-hauling in developing these muscles ; he also calls attention to the marked influence of this occupation in diminishing abdominal obesity. It may be observed, in passing, that all muscle exercises do not cause fat to disappear at the same rate all over the body. The fat tends to be absorbed chiefly in the neighbourhood of the muscles most actively employed. Thus, if a stout man takes to fencing, the loss of fat takes place chiefly about the chest, and similarly, rope-hauling, which calls the abdominal muscles into active play, is especially calculated to remove fat from the belly. The chief causes of abdominal flaccidity, with its con- sequent low intra-abdominal tension, are : a sedentary life, the wearing of stays (which prevent the free play of the abdominal muscles), and the distension of the abdominal walls produced by repeated pregnancies and by ascitic and adipose accumulations. Thus, the abdomen of a person who, from being very stout, has become rapidly thin, is very apt to be flaccid. Intra-abdominal tension is, of course, also diminished by paralysis of the abdominal muscles, as in myelitis and in idiopathic muscle-atrophy, of which I have a good example at present under observation. But the tension within the abdomen, though mainly dependent on the contraction of the abdominal walls, may be increased by other conditions. Thus, the pressure within the stomach and intestines varies from hour to hour even in health. Often it is negative, but it is frequently also positive ; e.(j., after a heavy meal it may be very decidedly positive, and may cause a considerable bulging of the upper part of the belly. (It is this positive gastric pressure which is the essential factor in causing dilated stomach.) Again, the stomach and intestines may be distended by flatus, and intra-abdominal tension is then much augmented, the abdominal walls often being stretched as tight as a drum. 12 RESPIRATORY EXERCISES Ascitic and other dropsical accumulations and abdominal tumours also greatly increase it. Quincke found the average intra-peritoneal pressure in ascites to be 25 mm. Hg. A full bladder increases abdominal tension. A large deposit of fat M'ithin the belly favours high tension. Secondary Effects of Low Intra-abdominal Tension. — A fairly high intra-abdominal tension is essential to health. "When the abdominal muscles fail to maintain adequate pressure on the underlying parts several evils result : (a) Dislocation of the abdominal viscerc is apt to occur. Bruce Clarke lays great stress upon the part taken by the abdominal muscles in maintaining the underlying viscera in their proper position. When the abdominal walls are habitually flaccid, all the viscera, including the liver, spleen, and pancreas, tend to travel downwards. This is a potent cause of floating kidney, which is never met with in those with well-developed abdominal walls. Visceral descent also causes lengthening of the mesentery and the ' bulging ' abdomen, and it leads to certain symptoms very common in women. ' There is pain in the back and a continued sense of weari- ness. Gastric symptoms are prominent ; the most con- spicuous are a sense of burning in the epigastric region, vomiting, pain, loss of appetite, distress after food, and more or less dyspepsia. . . . The symptoms are more or less relieved by pressing upon the lower parts of the abdomen with the two hands, or by the wearing of a supporting belt. Many patients are unable to move about until they have adjusted their supports or bands.'* {b) Constipation is induced. Increase of intra-abdominal tension is an important factor in defecation, and when the abdominal muscles are weak they are incapable of effecting the necessary degree of tension, and defalcation becomes difficult. * Treves, Brit. Med. Jour., 1896, vol. i., p. 1. INTRA-ABDOMINAL TENSION 13 (c) There is, as Leonard Hill has so well shown, a tendency for the blood to accumulate in the splanchnic area, with consequent syncope. The great sphinchnic veins, Hke tlie veins in general, are very susceptible to pressure, and the amount of blood they contain is largely dependent upon the pressure the abdominal walls exert upon them. Thus, a large quantity of blood may be squeezed out of them by simply pressing the belly firmly with the hand. Now, owing to the influence of gravity, the blood is very apt to accumulate in the splanchnic veins in the upright position ; and it is not, therefore, surprising that women, who so frequently suffer from abdominal flaccidity from the combined influences of child-bearing, tight-lacing, and bodily inactivity, should be prone to faintness or actually to faint, especially when the stays are removed. I have myself known of more than one instance of a woman fainting upon the removal of her stays. The same thing may happen, and for a similar reason, when a large quantity of ascitic fluid is suddenly removed, or even after emptying the bladder in the upright position — especially, as Lauder Brunton observes, if a patient with aortic regurgitation suddenly gets out of bed to do this. Stays correct the evil in question while they are on, but the most efficient stays are natural ones, in the shape of well-developed abdominal muscles. Li the normal subject the transversales in the upright position keep the anterior and posterior abdominal walls in firm contact, and prevent the undue accumulation, through gravity, of blood in the splanchnic area. Such an accumulation, with its consequent faintness, often occurs when a patient first gets up after having lain in bed for a long time. Leonard Hill attributes this to failure, through disuse, of the regulating vaso-motor action of the splanchnic vessels, which normally com- pensates for the effects of gravity in the upright position ; 14 RESPIRATORY EXERCISES but I think it may also in part be due to ^Yeakness of the abdominal muscles consequent upon disuse and, it may be, disease. In prolonged fever, for instance, the nutrition of the muscles always suffers. Since the above ^Yas written, Hill has published, in conjunc- tion with Harold Barnard, a second paper on the influence of gravity on the circulation,* in which the part played by the abdominal muscles in preventing the gravitation of blood into the splanchnic veins is worked out. They show that when the splanchnic vaso-motor mechamsm is intact it suffices of itself to prevent this, but that when, as by section of the splanchnic nerves, this mechanism is destroyed, a second mechanism comes into play in the shape of ' expiratory compressions of the abdomen occurring simul- taneously with inspiratory thoracic suctions,' the former squeezing, and the latter sucking, the blood out of the splanchnic pool. This enables the circulation to be carried on, though not so efficiently as before. We may speak of this as the respiratory mechanism. That the latter mechanism is not so efficient in compensation as the former is shown by the fact that the effects of gravity may be entirely compensated for after the injection of curare, which paralyzes the muscles and thus destroys the respiratory mechanism. This quite harmonizes with one's clinical experience. We sometimes meet with patients in whom this mechanism cannot operate, but who, nevertheless, are able to assume the vertical posture without fainting. Such are women with lax, atrophied abdominal walls and fixed emphysematous chests (in which, therefore, thoracic suction is practically absent). The ability of such to stand without fainting implies, of course, a vigorous state of the splanch- nic vaso-motor system. Both mechanisms may be destroyed by dividing the cord * Jour. I'hijH., vol. xxi., p. 323. INTRA-ABDOMINAL TENSION 15 at the first dorsal vertebra. If the animal operated on l)e then held vertically with the head up, the whole of the blood collects in the splanchnic veins, and * the empty heart con- tinues vainly to beat.' On compressing the belly, however, the blood is squeezed into the heart, and the circulation is re-established. {(I) The accelerating influence of the diaphragmatic movements on the circulation is interfered with. These movements, as will be shown in Chapter XIII. , play an important part in assisting the abdominal circulation by rhythmically increasing intra-abdominal tension ; but when the abdominal walls are \evy flaccid, the descent of the diaphragm will have little or no effect upon the tension, and consequently on the flow of blood in the intra-abdominal veins. (In the above experiment of dividing the cord, the diaphragm continues to act, inasmuch as the phrenics arise above the section. By its action it is able to increase thoracic suction slightly, and to squeeze a small quantity of blood out of the abdominal veins. The latter action is, however, infinitesimal, owing to the parah^zed state of the abdominal muscles, which prevents the abdominal pressure from being raised, except very slightly, by descent of the diaphragm.) The Action of the Abdominal Muscles. — The action of the transversalis abdominalis has been to « l^ygp pv^pnt ^ver- looked by anatomists. The superior fibres, stretching as they do across the costal arch, tend to narrow it, and thus to favour expiration. The middle fibres, taking their origin posteriorly from the lumbar fascia and stretching forwards towards the mid-abdomen, by their strong contraction bring the anterior and posterior abdominal walls in this region into firm contact, thus shutting ofi' the upper part of the abdominal cavity from the lower. This contraction 16 RESPIRATORY EXERCISES leads to considerable compression of the kidneys, and it does not seem improbable that the normal healthy tone of the transversalis has a good deal to do with keeping the kidneys in their normal position ; contraction of the middle fibres also presses the stomach, liver, and intestines firmly up against the diaphragm, and, by interfering with the descent of this structm'e, enables it to expend its energy in elevating the ribs rather than in flattening itself. The upper and middle portions of the transversalis may be said to constitute 'Nature's stays.' The lowermost fibres springing from the iliac crests and Poupart's ligaments cause by their contraction a flattening of the lower abdomen. The most transversely disposed fibres of the internal oblique have a similar action to the middle fibres of the transversalis, and retract the mid-abdomen. All those fibres of the external and internal oblique which are attached to the ribs are powerful expirators, and are capable of depressing the thorax with great force. In this way the diaphragm is carried downwards, and the abdominal cavity being thus diminished in height, the anterior walls tend to bulge forwards. The recti are very powerful muscles. They depress the sternum and ribs. Each rectus is capable of acting more or less independently of its fellow, and each fasciculus also has apparently independent action, and may contract independently in order to protect any painful tissue underlying it. These muscles play an important part in rendering the belly flat and in supporting the under- lying viscera. Method of testing the Tone of the Abdominal Muscles. — Whenever the tone of the abdominal muscles is defective, we can improve the condition of our patient by restoring them to a healthy state. The result of treatment directed INTRA-ABDOMINAL TENSION 17 to this end is sometimes quite remarkable. In all cases, therefore, where we have reason to suspect undue flaccidity of the abdominal walls, we should make a careful inspection of the abdomen. Sometimes the skin is so loose, the walls so flaccid, that it is quite easy to inspect and to palpate the various underlying organs. In such cases a wide interval can generally be felt between the recti. When, however, as often happens, the actual condition of the muscles is concealed by a copious deposit of fat, and the abdominal wall appears normal, even though its muscles be flabby and wasted, we should ask the patient gradually to raise the body while lying supine, or to bear down forcibly, and we shall then, by the feel of the muscles under the skin, be able to estimate their condition fairly accurately. When forming an opinion upon the state of the abdominal walls, we must bear in mind that normally they are con- siderably influenced by age and sex. In infants and young children the belly bulges very much, therein displaying a characteristic of man's quadrumanous ancestry, protrusion of the belly being a well-marked feature in the anthropoidal apes. A further characteristic of the young child's anterior abdominal wall is the separation of the recti. If, for instance, we observe the belly of an infant while it is lying on its back and endeavouring to sit up, we shall perceive a spindle-shaped swelling along the region of the linea alba. This is due to the protrusion of the fibrous membrane uniting the two recti, owing to heightened intra-abdominal tension. It is especially pronounced in infants who suffer from chronic flatulent distension — a common complaint with them. In such, the abdomen is more than usually prominent and the interval between the recti abnormally wide. As the child gets older the belly flattens, and the recti approach one another, and it is not until the belly has 2 18 RESPIRATORY EXERCISES attained the maximum flatness that the recti become fixed in close approximation, the fibrous membrane between them becoming so narrow that it can no longer be pro- truded. This takes place, according to my observations, at about the third or fourth year.* Accompanying this abdominal flattening is a similar flattening of the thorax, which, like the belly, is round in the infant and the anthropoids, and no doubt the process has in each case a similar object, i.e., the maintenance of the vertical position by keeping the centre of gravity vertically above the narrow basis of support afforded by the feet. The abdomen contmues flat in the male, if he remains in good condition, until the end of life ; but in the female a considerable deposit of subcutaneous fat occurs in the anterior abdominal wall at puberty, so that in the normal adult female the belly is rounded. Exercises for strengthening the abdominal muscles are given in Chapter XX. * I have, however, often noticed the protrusion referred to aboVe some time after the beUy has attained its maximum degree of flatness. CHAPTER III. THE ELASTICITY OF THE THORACIC CAGE. I USE the term ' thoracic cage ' to denote the chondro- osseous walls of the ' thorax,' this latter term signifying not only the parietes of the chest, but its contents also. The thoracic cage is elastic, i.e., its several parts, in- cluding the ribs, cartilages, sternum, spine, and also the clavicles (for they m a measure belong to it), are capable of being bent, and of springing back to their original positions when the bending force has ceased to act. John Hutchinson measured the elasticity of the thoracic cage by driving air into the lungs with sufficient power to rupture them, and then noticing the height to which the returning air was able to lift a column of mercury. In one case he found that by forcing in the amount of air which corresponded to the ' vital capacity ' of the individual — namely, 200 cubic inches — the returning air was able to raise 4" 5 cubic inches of mercury ; therefore the complete expansion of the chest in that case ' must have demanded a muscular power equal to resisting an elastic force com- mensurate to 4i inches of mercury, upon every square inch of his chest which was moved or expanded by muscle.'* Hutchmson further calculated that this man, in taking a deep inspiration, must have exerted a muscular power capable of raising 450 lbs. ; and in another case he found that the thoracic elasticity must have equalled 1,000 lbs. * Med. Chir. Trans., 1846. p. 207. 2—2 20 RESPIRATORY EXERCISES The elasticity of the ribs, cartilages, and sternum is greatest in early life. Hence, in young children the thorax is very easily compressed. With advancing years, especially in old age, these structures tend to become increasingly rigid from the deposit of lime salts in them, and we therefore frequently find the costal cartilages calcified. Humphrey regards this change as a morbid rather than a normal senile change. He points out that the costal cartilages of old people can often be as readily cut with the knife as those of the young, and he found that in one man a hundred years old they contained no excess of mineral matter. Calcification of the costal cartilages is more common in men than in women. The elasticity of the thoracic cage serves several useful ends : 1. It enables the component parts of the cage to be so bent during the respiratory movements as to increase or diminish thoracic capacity. One is apt to think that the sternum, ribs, and cartilages always preserve the same form, and that they have exactly the same curvatures at the end of a deep inspiration or expiration as in the mean position of the thorax ; but such is far from being the case. During a deep inspiration the anterior vertical convexity of the sternum increases, the upper costo-cartilages tend to bulge forwards beyond the sternum, while the ribs themselves undergo considerable bending. For the most part they straighten out, the posterior bends, or ' angles,' however, becoming more pronounced, as may be felt by placing the hand upon them during a deep inspiration. These various structures are also bent during a deep expiration, but in a contrary manner. The former we may term the ' in- spiratory,' and the latter the ' expiratory,' bend. The mean or neutral position of the thoracic cage — i.e., that position in which its constituent parts are THE ELASTICITY OF THE THORACIC CAGE 21 wholly unbent — does not, as one is so apt to suppose, correspond to that attained at the end of an ordinary expiration, for then the thoracic cage is bent somewhat inwards by pulmonary suction. It more nearly corresponds to the position which the chest assumes at the end of an ordinary inspiration. The fact is that ordinary expiration starts at about the neutral position, the lungs during the entire period of expiration sucking in the thoracic cage beyond that position. This is shown by the fact that when the chest is opened after death, and pulmonary suction thus arrested, the thoracic cage expands. The inspiratory and expiratory bends induce recoils which become factors in producing the respiratory move- ments. Thus, at the end of an extraordinary inspiration the cage recoils by virtue of the inspiratory bend towards the neutral point, being helped in this movement by pul- monary suction ; and, similarly, at the end of an extra- ordinary expiration an outward recoil occurs by virtue of the expiratory bend, this movement being, of course, assisted by the action of the costal elevators. The part played by thoracic recoil in ordinary, tranquil breathing requires special reference. We have seen that at the commencement of an ordinary expiration the chest is in the neutral position, or nearly so, and that it becomes bent inwards during the expiration ; consequently, at the end of it an outward recoil is available as an inspiratory force, and carries the cage back towards the neutral position, which, according to Douglas-Powell, is barely reached in ordinary inspiration. Inasmuch, therefore, as the move- ment of the ribs during ordinary inspiration is purely a matter of recoil, ' the sole resistance to be overcome by the inspiratory muscles is that of the lungs.'* * Douglas-Powell arrives at the above conclusion in the following way. After death, when the chest is in a position of ordinary expira- 22 RESPIRATORY EXERCISES What happens, then, is this : During expiration the ribs, cartilages, and sternum are bent into a position from which they tend to recoil outwards, and during inspiration the insph-atory muscles exert just sufficient force to overcome pulmonary suction, the thoracic cage by its passive recoil assuming the position attained at the end of ordinary inspu'ation, and not offering any dead weight to be raised by the inspiratory muscles. It, however, appears to me an error to suppose, as Douglas-Powell apparently does, that inspiration is facilitated by this arrangement. '■= 2. The elasticity of the thoracic cage enables its com- ponent parts to move more or less independently of one another. Consider what would happen if the ribs, carti- lages, and sternum were absolutely rigid. It would then he impossible, unless we assume a preternatural laxity of the joints, to move one rib without moving all the others to the same degree. As a matter of fact, however, during a deep inspiration, the upper ribs approximate to one another, while the intervals between the lower ribs increase. Andral long ago pointed out that the ribs can move independently of one another,! and Sibson refers to the independent action of each intercostal muscle.* It is, moreover, pos- tion, the thoracic cage is bent inwards beyond the neutral point ; for upon opening the pleurae, and thus removing pulmonary suction, the girth of the chest is increased from 1"68 mm. to 3"9 mm.; but the thoracic girth in ordinary inspiration is only increased by 2 to 3 mm., and hence he concludes that in the ordinary quiet inspiration of health ' the limit of thoracic recoil is barely reached.' Oj). cit., pp. 6-19. * Suppose pulmonary suction were not sufficiently powerful to draw in the bony thorax during ordmarj- expiration, there would be so much the less opposition to the in.spiratorv muscles. The inspiratory muscles have to overcome pulmonary suction minus tlie force of the outward recoil of the thoracic cage. If we suppose pulmonary suction to diminish by this amount of force, so that the ribs are not drawn in, as may happen in emphysema, the force to be overcome by the inspiratory muscles will obviously remain the same. t Clin. Med., tom. i., p. 68. J Med. Chir. Trans., vol. xxxi., p. 3.53. THE ELASTICITY OF THE THORACIC CAGE 23 sible — especially in women, whose upper ribs acquire unnatural mobility from the use of stays — to expand the upper chest more than the lower, and it is still more easy to do the converse of this.* It is also possible, after a. little practice, voluntarily to expand one side of the chest independently of the other, or nearly so. In a patient who had long suspected tubercle of the right apex, I found the movement on this side greater than on the other : by constant attention to it, he had got into the habit of expanding it more than the other. Again, inequality in the movement of the two sides of the chest is frequently observed in disease ; the whole of one side may be prac- tically immobile, or the defective movement may be limited to two or three ribs. 3. Thoracic elasticity enables the cage to adapt itself to alterations in the volume of the thoracic contents. Thus, in phthisis the parietes tend to fall in, while in pleural effusion and cardiac enlargement the overlying walls tend to bulge. This adaptation is the more com- plete the greater the elasticity of the cage, and it is therefore more complete in the young than the old. It serves, be it noted, a useful purpose. Thus, if the chest- wall did not fall in in phthisis, not only would there be a considerable upward dislocation of the diaphragm, and con- sequently of the heart and abdominal viscera, but also great stretching of the bronchi and alveoli. Again, a greatly enlarged heart may cause dyspncea, especially in children, by encroaching on the space which should be occupied by the lungs, and it is precisely in children that precordial bulging is most easily effected. Such bulging, indeed, always accompanies any considerable cardiac en- largement in their case, and may be so well defined and so decided as to render it almost possible to map out the shape * See p. 57. 24 RESPIRATORY EXERCISES of the heart on mere inspection. It should also be observed that the enlarged heart often makes room for itself by thrusting the diaphragm downwards ; one can sometimes, indeed, almost grasp the heart in the epigastrium. The degree of thoracic elasticity is important in relation to external compression of the thorax. A rigid chest resists compression ; an elastic one readily yields to it. It would not require much compression of a child's chest to destroy life completely, while it would take a good deal of force to produce the same effect in a very muscular middle-aged man. The effect of external compression of the chest on the circulation will be considered later. Suffice it here to say that it impedes the output of blood from the right heart, damming it back upon the great veins. Hence, as Hill and Barnard observe, ' it is the weaker women and children with compressible chests that, are first affected in panic-stricken crowds. . . . The stronger man with a rigid chest escapes.'* The elasticity and consequent compressibility and resiliency of the thorax are of practical interest in relation to artificial respiration. The more elastic the chest, the better can artificial respiration be carried on, and it is partly to this fact that Leonard Guthrie attributes the better recovery from chloroform collapse of children than adults. t In the former case he recommends the application of rhythmic pressure to the lower part of the thorax, while in adults he prefers Silvester's method. * Jour. Phijs., vol. xxi., p. 334. t Clin. Jour., March 24, 1897, p. 336. CHAPTEE IV. THE FACTORS DETERMINING THE MEAN SIZE OF THE CHEST. What are the factors determining the mean size of the chest — i.e., its size when midway between ordinary inspira- tion and expiration ? We do not answer the question by saying that the size of the chest depends upon that of the lungs, since this statement gives no clue as to the way in which the correlation is effected. We know, for instance, that pulmonary phthisis diminishes the size of the lungs, and that the chest-walls tend to collapse in consequence ; on the other hand, we know that exercises which develop the lungs expand the chest, and we are apt to assume that the collapse in the one case is due to diminished pulmonary support, and the expansion in the other to an actual thrusting outwards of the chest-walls from pulmonary hypertrophy. Seeing, however, that pulmonary suction tends to draw in the chest-walls, this latter assumption is manifestly wrong. How, then, are we to explain the correlation between pulmonary development and chest capacity? Given ribs, sternum, heart, etc., of certain size, thoracic capacity will depend upon two main factors : (a) The degree of pul- monary suction tending to contract the chest, and (/>) the excess of tonic contraction of the muscles expanding the thoracic cage over that of the corresponding contractors. 26 RESPIRATORY EXERCISES (a) Pulmonary suction is increased in phthisis during ordinary breathing, for destruction of pulmonary tissue leads to excessive stretching of the unaffected parts — i.e., to an undue drag upon the visceral pleura, this being still further increased by the contraction of scar tissue within the lungs. Hence, the collapse of the chest -walls in phthisis does not result from diminished support from within, but rather from increased pulmonary suction.* I say that pulmonary suction is increased in phthisis in ordinary breathing. In health it is greater during extra- ordinary inspiration than it is in phthisis. Pulmonary suction is, on the other hand, diminished by exercises tending to develop the lungs, for the more per- fectly the air-passages and alveoli are developed — and it must be remembered that in ill-developed lungs a number of alveoli are partly or completely collapsed — the less will the elastic elements of the lungs be stretched, and the less will be the traction upon the visceral pleura. Hence, increased development of the lungs expands the thorax, not by thrusting it outwards, as Lagrange assumes,! but by diminishing the suction on its inner walls. (h) Next as regards the muscle factor. First be it noted that the thoracic elevators are much more constant in their action than the corresponding depressors, for ordinary expiration may be regarded as purely passive, while even in the extraordinary breathing attending muscle exercise the inspiratory muscles are much more actively engaged than the expiratory. This is because breathlessness tends to excite the insjnratory muscles more tlian tlie exinratory * The lungs are frequently adherent to the chest-walls m phthisis, and in such cases we may speak of the adherent portions as actually (Iragtjivrf in the thorax, rather than as sucking it in. t Lagrange rightly observes that muscle exercise develops the lungs and enlarges the thorax essentially by inducing breathlessness, but he does not explain how breathlessness produces this result. FACTORS DETERMINING THE MEAN SIZE OF CHEST 27 (see p. 93). The influence of the thoracic elevators thus preponderating over that of the depressors, the tendency of muscle activity is to increase thoracic capacity. There can be no doubt that the breathlessness attending muscle exercise leads to an increase in the mean size of the chest. Such an increase occurs during running, rowing, and the like. Thus, during a hundred yards' sprint the chest is always very prominent, the respiratory movements taking place about a larger mean than ordinary, so that, while inspiration exceeds the average, expiration does not reach its usual limit. This increased mean thoracic capacity during muscle activity has a double advantage, for not only is the mean respiratory area thereby increased, but the resistance in the pulmonary circuit is diminished* — a great advantage, seeing that the right heart is so apt to be distended m violent muscle exercise. Such exercises as mounting a ladder, running upstairs, hill - climbing, and diving, tend, by the dyspnoea which they induce, to cause great expansion of the chest. So greatly, indeed, may the chest be expanded in this way that the lungs may become unduly stretched, and their elasticity thus permanently iajured. Now, loss of pulmonary elasticity is a potent cause of emphysema, and hence it is that exercises of this kind may actually induce it.t Those who inhabit mountainous regions and who thus habitually breathe rarefied air, have expanded chests. This is because the inspiratory muscles are excited to extreme activity by the breathlessness which the rarefied air is apt to induce. We see now how it is that those with strong muscle systems and leading active lives have more capacious chests than those with weak muscle systems and leading sedentary lives. It is among the latter that the phthinoid chest is * See Chapter XIII. f Sec Chapter XXII. 28 RESPIRATORY EXERCISES most frequently found — the cliest of superextraordinary expiration, as we may term it, in which the clavicles, scapulfe, and sternum are low, the ribs very oblique, the sagittal diameter small, the costal arch very acute, and the diaphragm high, the heart being correspondingly high up and superficial. The opposite type of chest is met with in subjects of strong muscle development : the clavicles, scapulae, and sternum in them are high, the ribs less oblique, while the chest is deep, the costal angle well opened out, and the diaphragm low, the heart being correspondingly low and also deep. The typical large - lunged emphy- sematous chest is an exaggeration of this, and may be termed tlie chest of superextraordinary inspiration. How large a share the muscles take in determining the mean size of the thorax is well shown by the effects of paralysis. I have now under my care a boy suffering from idiopathic paralysis. Several of the cervical muscles are paralyzed, he has no power of flexing the neck or head, the scaleni are practically absent, while the sterno-mastoids are reduced to riband-like bands. In consequence of this the sternum has descended a good inch, the ribs being cor- respondingly oblique, and the chest very flat. The clavicles, instead of being horizontal, or nearly so, as they should be, slope markedly downwards and inwards, their outer ends being maintained in position by the trapezius, which is not paralyzed. This marked downward and inward slope of the clavicles is, I believe, frequently met with among those with feeble muscle development and phthinoid chests, and is a feature to be sought for. Seeing that a feeble muscle system is common among those actually afflicted with phthisis, we have an additional reason why the thorax should collapse in this disease. All diseases which enfeeble the muscle system tend to diminish the chest capacity. Thus, I have little doubt FACTORS DETERMINING THE MEAN SIZE OF CHEST 20 that in the course of a long debilitating disease, such as typhoid fever, the thorax undergoes a decided diminution, provided, of course, it be not already fixed from age. The same may even happen if a sedentary existence succeed to an active, outdoor life. Conversely, a single long walk may temporarily increase the chest capacity in one leading a sedentary life. Not only the breathlessness of muscle exercise, but also that induced bj' disease, tends to cause expansion of the chest, and in the same way — namely, by exciting the inspiratory more than the expiratory muscles. Indeed, in most cases of dyspnoea from disease the chest is found to be in a state of inspiratory expansion, this expansion not only increasing the respiratory area, but facilitating the pulmonary circulation which is then so apt to be impeded. It should be observed that thoracic expansion does not occur in the dyspnoea resulting from considerable obstruc- tion in the air-passages, which, on the contrary, induces collapse — a condition likewise favoured by weakness in the inspiratory muscles and chest wall, and hence its fre- quency in the bronchitis of marasmic and rickety children. Wilson Fox observes that the chest is generally expanded in cardiac dyspnoea, and I can bear out this statement. We can on similar lines explain — partly at least — the expansion of the chest during the asthmatic paroxysm.* The important part taken by the inspiratory muscles in determinmg the mean size of the chest is well shown by the expansion of the thoracic cage which takes place at birth. I believe this to be due to tonic contraction of certain thoracic elevators. Before birth the lungs are collapsed. Immediately after birth they expand, and the * See Wilson Fox, ' Treatise on Diseases of the Lungs," pp. 65-67. 30 RESPIRATORY EXERCISES thorax is correspondingly enlarged ; this enlargement could not be maintained except by muscle-action. It is true that pulmonary suction is absent in the new-born animal (the lungs suffering no- collapse if the pleurae are opened immediately after birth), and consequently the thoracic cage is subjected to the same pressure on its inner as on its outer side ; but even with this supporting pressure from within, the cage would yet surely tend to shrink to its ante- partum dimensions did not the expansile forces of respiration preponderate over the contractile.* Moreover, it is not long before pulmonary suction is established, and this, I suggest, is due to the gradual increase in the mean size of the thoracic cage, owing to the preponderating action of the costal elevators, the elastic fibres of the lungs being thereby put on the stretch, rather than (as has been sug- gested) to the thoracic cage growing more rapidly than the lungs, though such inequality in rate of growth may con- tribute to the result. We have not yet explained why the mean size of the chest should be jJermanently increased as the result of long- continued overaction of the inspiratory muscles, and why it does not shrink to its pristine dimensions directly excessive inspiratory action ceases. Suppose that, by means of suitable exercises, we increase the mean thoracic girth from 32 to 36 inches ; this signifies that the clavicles, ribs, and sternum are held in a new mean position, that there has been estab- lished a new mean position about which the respiratory movements take place. It may, indeed, be no longer * Among the expansile forces of respiration we must, of course, include the action of the diaphragm. This is the chief respiratory muscle in the infant, and it might be argued that the increase in mean thoracic capacity brought about at birth is not due to an increase in the capacity of the cage, but to a lowering in the mean level of the diaphragm from tonic contraction of its muscle fibres. I imagine, however, that there can be little doubt that the capacity of the thoracic cage is actually increased at birtli. FACTORS DETERMfNING THE MEAN SIZE OF CHEST 31 possible for an individual whose chest has been thus increased to make it, by the most forcible expiration, as small as before the exercises were undertaken.* How is the chest fixed in this new position, and why does it not return to its original size when excessive inspiratory action ceases ? This question has never, so far as I know, been discussed. There are at least two factors tending to fix in a new position a chest which has been chronically expanded : (a) Permanent shortening, or contracture, of the thoracic elevators. Long-continued overaction of these muscles increases their tone, namely, their permanent contraction. They remain chronically contracted, no longer relaxing to the same extent as before the period of their overaction. This, in course of time, leads to their organic shorten- ing, or contracture, for there can be no doubt that long- continued overaction of a group of muscles does lead to such shortening. Thus, it is owing to the preponderating action of the great flexors of the trunk that gymnasts so often contract the stooping posture, and the habitual flexion of the forearm observed among horse-riders may be ex- plained on the same principle. A still more remarkable illustration is afltbrded by the extreme shortening that takes place in muscles whose antagonizers have become paralyzed. It is to a similar shortening of the thoracic elevators that the permanent expansion of the chest above referred to is largely attributable. (l)) Alteration in the joints, their articular surfaces and ligaments undergoing changes adapting them to their new position. In later life a veritable ankylosis of them may occur. * I am referring to ordinary cases. In instances it might be possible for the individual whose chest liad been considerably expanded by exercises to reach his original expiratory limit. This, however, would necessitate gi-eat thoracic mobility, and would probably only be possible if special exercises for mcreasing expiratory mobility were resorted to. CHAPTEK V. THE MOBILITY OF THE THORACIC CAGE. The mobility of the thoracic cage is determined by many circumstances, such as the expansibility of the lungs and the condition of the abdominal viscera. There is, however what may be termed an intrinsic mobility of the thoracic cage, due to its elasticity and the mobility of its various joints, independent of conditions within and without the chest, and capable of being accurately tested in the freshly- prepared ' ligamentous thorax.' Among the factors determining thoracic mobility, special reference must be made to the action of certain thoracic muscles. Thus, depression of the ribs may be limited by permanent shortening of the costal elevators. Individuals differ very considerably in respect of thoracic mobility. The most mobile chests are met with in the young, for in them the bones and cartilages are very flexible and the thoracic joints freely movable. With advancing years the thoracic cage gets less and less mobile, until in old age it may become almost completely fixed. This is due to increasing rigidity of the bones and cartilages, to stiffness and even ankylosis of the thoracic joints, and generally also, I believe, to contracture of the thoracic elevators. We must not neglect to reckon among the thoracic joints the articulations between the costal cartilages and the THE MOBILITY OF THE THORACIC CAGE 33 sternum. These joints are provided with synovial mem- branes and admit of considerable movement. In old age, however, they tend to disappear, the cartilages undergoing calcification and becoming welded with the sternum, with which they then form one rigid piece. In like manner the costo- vertebral joints tend to stiffen with age, owing, apparently, to shortening and thickening of the ligaments, and to the deposition of new bone in the neighbourhood of the joints. Thoracic mobility, as John Hutchinson's classical obser- vations show, tends to increase with stature, and it is owing to this circumstance rather than to increase in mean thoracic capacity that ' vital capacity ' tends to increase with it also. Arnold* confirms Hutchinson's observation as to the relation between stature and thoracic mobility. He finds the average thoracic mobility for various heights to be as follows : Height. Chest mobUity. 157 to 165 cm 6-5 cm. 165 „ 170 171 „ 175 177 „ 180 181 „ 191 7 7-5 8 8-5 Arnold also finds that the mobility of the chest tends to increase, though not to the same extent, with its girthf as well as with the height of the individual. This is not surprising, seeing that the height and girth of the thorax tend to increase together. While the most rigid chests are most frequently met with in the aged, rigid chests, as Frederick Eoberts observes, are not uncommon in young subjects, in whom they are often * "Waklenburg, ' Die Pneumatische Beliandlung der Eespirations- und Circulations-kranldieiten.' Berlm, 1880, s. 161. t Ibid., s. 115. 3 34 RESJPIHATORY EXERCISES traceable to ' hard, physical work, and excessive indulgence in athletics and allied exercises.'* I believe that the breath- lessness induced by excessive muscle exercise is largely responsible for the fixity of the chest in these cases, leading as it does to overaction and contracture of the thoracic elevators, and not infrequently to actual emphysema also.f Another cause of thoracic rigidity in muscular subjects has been suggested to me by Dr. McCann. It is that powerful thoracic muscles imply correspondingly strong ribs and sternum. We know that the skeleton is more mas- sive and that the roughened osseous surfaces for the attach- ment of muscles are more pronounced in those of powerful muscle development than in those with feeble muscle systems, and we can scarcely doubt that this implies a corresponding rigidity of the bones. Hence laborious muscle exercise must be included among the causes of thoracic immobility. All diseases which induce breathlessness tend in like manner to limit the mobility of the chest, and in consequence we never find a freely mobile chest in those suffering from emphysema, + chronic bronchitis, and serious heart disease. Another cause is the inactivity of the muscle system with its consequent restriction of respiratory movement. It is indeed astonishing how immobile the chest generally is in those leading sedentary lives. This is especially noticeable among women, many of whom seldom, if ever, resort to deep breaths. The breathing being thus habitually shallow, the respiratory range graduall}^ narrows. Defective moljility does not always involve the entire cage equally. Thus, in the civilized woman the lower part may, owing to the use of stays, be comparatively fixed, while the * Dr. Iloberts does not explain how the rigidity is broujjht about. t See Chapter XXII. % The way in which emphysema induces fixity of the chest is con- sidered in detail in Chapter XXII. THE MOBILITY OF THE THORACIC CAGE 35 upper part may be abnormally mobile. In the man, on the contrary, the defective movement may be most notice- able in the upper part. Means of testing Thoracic Mobility. — Thoracic mobility may be estimated in various ways. The most accurate method is to ascertain the relation between ' vital capacity ' and the mean size of the thorax. The greater the former in relation to the latter, the greater the mobility. There is no convenient way of exactly determining mean thoracic capacity, but for all practical purposes it may be arrived at by adding the girth and height (measured in the nipple line) of the thorax. In this way we obtain a figure which bears a fairly constant ratio to capacity.* Another plan is to take the difference between thoracic girth at the end of a complete mspiration and expiration. The measurement should be made both at the level of the nipples and of the xyphoid cartilage, seeing that mobility is sometimes greater at the one end and sometimes at the other. The average difference between maximum and minimum in the male adult is, in my experience, about 2 inches. Fetzer found it to range among 392 recruits between 4 and 12 cm., the range being most generally between 6 and 10 cm. I have known a man to claim a difference of 6 mches, but this must be very exceptional. At Barnum's Show in London a few years back was a man possessed of extraordmary chest mobility. By forcibly expanding his thorax he was able to snap a strong belt fastened round the chest when in the position of full expira- tion. It should be mentioned that those endowed with large and powerful thoracic muscles can effect a consider- able increase in thoracic girth simply by contracting these * In the case of the very stout it may be necessary to take oti' some inches from thoracic gu-th in order to arrive at the right measurement. 3—2 36 RESPLRATORY EXERCISES muscles, and thus causing them to swell up. Sandow, for mstance, claims to be able to increase his chest circum- ference from 48 to 62 inches — i.e., to the extent of 14 inches. I have little doubt that this increase is brought about almost entirely by the swelling up of the great muscles enveloping the chest. It is probable that the increase in his bony chest is not more than from 2 to 3 inches, seeing that his vital capacity is only 275 cubic inches. Thoracic mobility can further be tested by noticing the degree to which the costal arch opens up and closes during an extreme inspiration and expiration ; also by observing the extent to which the episternal notch can be raised and depressed. In a very mobile chest it can be made almost to touch the chin when the head is held erect. This latter test is, however, somewhat unreliable, seeing that in some cases the chest may be lifted in mass without undergoing appreciable expansion. By means of respiratory exercises the mobility of the chest may be very considerably augmented, these exercises leading to development of the lungs and respiratory muscles and to increased flexibility of the ribs and sternum, as well as to a loosening of the thoracic joints when these have become stiff. The j^ounger the subject, the greater is the gain in mobility likely to be. If he be under twenty-five years of age, he may be able to increase a maximum- minimum difference of 1^ inches to 3, 4, or even more inches, and even after middle life we may effect a consider- able augmentation. Not only are we thus able to increase thoracic mobility, but also to delay the advent of senile rigidity. It is not surprising that the latter should set in prematurely in those who seldom or never resort to extra- ordinary breathing. For means of increasing thoracic mobility the reader is referred to Chapter XXI. CHAPTER VI. THE PLEURA AND THEIR FUNCTIONS— THE MOVEMENTS OF THE LUNGS. The Functions of the Pleurae. — The pleurse consist of two large lymphatic sacs into which the lymph is pumped from the peritoneum by the respiratory movements and thence through the lungs and thoracic j)arietes. Their chief function is to enable the lungs to expand equally and in all directions. Seeing that the visceral and parietal surfaces are in apposition, and that the lungs in conse- quence remain in contact with the chest-wall, every expan- sion and contraction of the chest leading to a corresponding expansion and contraction of the lungs, the question not unnaturally occurs. What need is there for the pleurae ? Why should not the lungs be adherent to the chest-wall '? The answer is a simple one : It is because such an arrange- ment would not permit of their equal expansion in all directions during inspiration. Simple diaphragmatic breathing, e.g., would cause the lowermost vesicles only to expand, and these very unequally, seeing that all parts of the diaphragm do not move to the same extent, while the upper portions of the lungs would probably suffer no expansion whatever. By means of the pleura, however, the lungs are enabled to move in various directions within the chest, and thus to expand in all their parts, so that even in pure abdominal inspiration, in which the thorax 38 RESPIRATORY EXERCISES enlarges iii the vertical diameter only, the upper parts of the lungs are enabled to expand freel}'. It has been urged — among others by Oertel — that when the diaphragm descends, it is the basic portions of the lungs that are chiefly expanded, and that when, on the other hand, the upper part of the thorax is expanded more than the lower, pulmonary expansion takes place in the apical regions chiefly — in short, that the lung expands most when the movement of the overlying chest-wall is most marked. Sibson held the same view, and enunciated it in precise terms.* There can be little doubt that it is correct, though I think Oertel and Sibson push it too far. Thus, during an abdominal breath air appears, from the test of auscultation, to enter the apices freel3% It is therefore questionable whether there is anj^ foundation for the view that tubercle is prone to attack the apices, because in ordinary breathing, which is mainly abdominal, they expand much less than the bases. When, however, the pleurae are adherent, the case is different, for whatever interferes with the upward and downward gliding movement of the lungs within the chest will necessarily interfere with the proper ex^mnsion of the apices in ordinary breathing. Hence, those with pleuritic adhesions should frequently resort to costal breathing. The Lower Limits of the Pleurae. — It is necessary to ascertain the lower limits of the pleurae, for these deter- mine those of the lungs when expanded to their fullest *■ According to this authority, ascent of the first five, or thoracic ribs expands the superior and middle lobes ; elevation of the sixth to eighth, or intermediate ribs, expands ' the upper portion of the lower lobe, and on descent of it, the lower portion of the upper lobe '; while elevation of the ninth to twelfth, or diaphragmatic ribs, expands the lower and back part of the lungs. — Med. Chir. Trans., vol. xxxi., pp. 357-359. THE PLEURAE AND THEIR FUNCTiONS 39 possible extent. Each pleura extends downwards as far as the attachment of the diaphragm to the thorax. It is stated by some writers that the diaphragm is attached to the rim of the costal arch, and this gives the erroneous impression that the lungs may extend as far as this. Such is, however, not the case. Posteriorly, the diaphragm is. attached to the bodies of the lumbar vertebra3, to the tip of the transverse processes of the tirst lumbar vertebrae,, and to the twelfth ribs ; outside this it is attached to the lower margin of the costal arch and to the ihiwr aspects of the last six ribs, this internal attachment extending in the mid-axillary line about 1 vertical inch, and in the nipple line about 2 inches, beyond the arch, while inside this line it gets progressively smaller. Thus, the upper limit of the diaphragmatic attachment, and consequently the lower limit of the pleura, does not correspond with the costal arch, the margin of which the lungs can therefore never be made to reach. The Movements of the Lungs within the Chest. — During ordinary breathing the lungs move forwards and down- wards, movement being most marked below and in front — i.e., where the thorax is most movable. Hence, pleuritic adhesions cause a greater interference with the movement of the lungs in this situation than elsewhere. In the posterior and apical regions they interfere very little with pulmonary movement. The way in which the lungs move within the thorax depends very largely upon the way in which the latter is expanded. In the woman, in whom the chest is more movable above than below, there may be — especially when the stays are worn — a gliding upwards of the lungs during tranquil inspiration ; in purely abdominal breathing the movement is almost entirely downwards, while in a costal breath with lixed clavicles it is almost wholly forwards. In 40 RESPIRATORY EXERCISES a costal breath with elevation of the clavicles it is upwards as well as forwards. It may here be observed that it is possible to move the lungs within the chest without actually breathing. Thus, the diaphragm may be made passively to ascend and descend — the lungs, of course, following — by alternately raising and depressing the lower ribs with closed glottis ; and, similarly, the lower costal chest may be made passively to contract and expand by contracting with closed glottis, first the diaphragm, and then the transversales abdo- minalis. It is useful to ascertain the limits within which the pulmonary margins are capable of moving, for in this way we can gain information as to the presence of pleuritic adhesions, and also as to the effects of treatment. Inasmuch as the lower pulmonary margins travel up and down with the respiratory movements, it is clear that they have no fixed boundary, and that they cannot correspond to the lower limits of the pleurae. As a matter of fact, the lungs only extend thus far when the fullest possible inspira- tion is made, and then only if well developed. The mean position of the lower pulmonary margin differs somewhat on the two sides, owing to the asymmetrical position of the heart. It is roughly represented by a line drawn from the sterno-xyphoid articulation sloping slightly downwards to the spine, and cutting the upper border of the sixth rib in the nipple line, the eighth rib in the axillary line, and the tenth rib posteriorly. The extent to which the lower margin of the lung travels down in ordinary inspiration may be ascertained l)y {a) in- spection and (/>) percussion. (a) During the movements of the diaphragm the liver moves up and down, but it does not move bodily, the coronary ligament fixing the organ posteriorly, and allowing THE PLtURiE AND JIIEIR FUNCTIONS 41 it to swing iTp and down, as upon a hinge, so that the movement is greatest in front and least behind. Now, it is probable that the movement of the anterior margins of the liver and of the lower pulmonary margin in front practically correspond, and we are sometimes able, by careful inspection of the abdomen, to see the anterior margin of the liver moving. I have several times observed this, both when the liver has been normal and when enlarged. The extent of the movement is about half an inch in ordinary, and nearly 2 inches in extraordinary, breathing ; and we may accept these figures as representing the extent to which the lower margin of the lung moves in each case. I have been able to ascertain by inspection that the downward movement of the lung is as great posteriorly as anteriorly. A child, five years of age, had considerable collapse of the right lung in consequence of empyema, the left lung being compensatorily hypertrophied, and its movements correspondingly exaggerated. There was ex- treme emaciation, and this enabled me to observe, through the thin chest wall, the ascent and descent of the lower edge of the hypertrophied lung. (h) Percussion in suitable subjects confirms the results obtained by inspection. The breath is held at the end of an ordinary inspiration, and the lower margin of resonance then carefully percussed by means of Sanson's pleximeter. When the disturbance in breathing due to this cessation is recovered from, the breath is again held at the end of an ordinary inspiration, and the line of resonance similarly percussed. In like manner we can ascertain to what degree the line of resonance alters in extraordinary breathing. In a well-developed man, with free chest movement, the difference between the uppermost and lowermost limits of the lower margin of the lung in the nipple line is 42 HESPLRATORY EXERCISES about 4 inches, the lung in a complete inspiration travelling nearly as far as the costal arch, and after a complete expiration receding to 4 inches or more above this. The lower margin of the lung, as judged by per- cussion, is the same in a full costal as in a diaphragmatic inspiration, and practically corresponds to the costal arch — i.e., resonance can be got in each case right down to the edge of the arch — a fact the more remarkable when it is reflected that the lung cannot actually extend thus far. There can be no doubt that the margin of the lung travels as far down in a complete costal as m a complete diaphragmatic inspiration, because the diai^hragm flattens in the former case, owing to the elevation of the costal arch. The line of resonance in a complete diaphragmatic expiration is rather lower than in a complete costal expha- tion, as one would expect. The movements of the anterior margins of the lung can also be ascertained by percussion. In well-developed lungs the superficial area of cardiac dulness can be obliterated by a deep inspiration. CHAPTEE VII. INSPIRATORY AND EXPIRATORY FORCE. '^ The force with which the air is inspired and expired we term respectively inspiratory and expiratory force. It is measured by means of a graduated U-shaped glass tube, partly filled with mercury, to one end of which is attached a flexible tube, which is applied to the mouth or nose. An inspiration or expiration is then made, and the alteration in the height of the mercury read off. "When the operation is done _2Jc>- oram, a mouthpiece is fitted on to the free end of the tube, and introduced well back on to the base of the tongue. Care must be taken that the buccal cavity is not shut off from the naso-pharyngeal during the operation, for if this should happen the mercury may, on the one hand, be sucked up, instead of breathed up by the inspiratory forces ; while, on the other hand, it may be driven down by the contraction of the buccinators, as in blowing a wind instrument, instead of being forced down by the expiratory forces. This difficulty is obviated when the operation is performed * Our earliest knowledge of this subject we owe to two English workers — Hales and Hutchinson. "Within recent years it has been taken up on the Continent by Donders and a number of German observers. Foremost among these is Waldenburg, to whose work, ' Die Pncimiatische Behandlung dcr Respirations- und Circulations- krankheiten,' BerUn, 1880, I am mainly indebted for tlie substance of this chapter. 44 , RESPIRATORY EXERCISES by -^ay of the nares. In this case a nose-piece is attached to the tubing, and inserted into one nostril, inspiration and expiration being made with closed mouth, and with the nose so held that the entire current of air is directed along the tube. The objections to this method are its unpleasant- ness and the extreme frequency of nasal obstruction. All the above objections are avoided by the employment of a mask, fitted, in air-tight fashion, to the face, over the nose and mouth, the latter being kept wide open during the operation, and care being taken not to pfess the mask too tightly against the face, as by modifying the air-pressure within it may influence the height of the mercury. Breath-power may be tested either by a sudden forced breath or by a slow gradual one. In the former case the influence of inertia causes the modifications in the height of the mercury to be greater than in the latter ; but it is, for practical purposes, the better method. In testing a subject, several observations should be taken, and the maximum result recorded. Some instruments are provided with a special mechanism for registering this. In tranquil breathing the mercury moves from 1 to 2 mm. ; in forced breathing the movement is very much greater. Thus, in average adult men inspiratory force varies from 80 to 100 mm. Hg ; expiratory force, from 100 to 130 mm. Hg. In women the former is represented by from 60 to 80 mm. Hg, the latter by from 70 to 110 mm. Hg. It will thus be seen, as John Hutchinson long ago pointed out, that expiratory force is about one-third greater than inspiratory. This difference is not due to a corresponding difference in the strength of the expiratory and inspiratory muscles, but to the fact that the former have to overcome pulmonary suction, the elasticity of the thoracic walls, and the weight of the thorax — all of which aid the respiratory muscles in the act of expiration. We thus see how it comes about that the full expiratory force can only be obtained INSPIRATORY AND EXPIRATORY FORCE 45 after a full inspiration, while the full inspiratory force can be obtained as well after an ordinary as after an extra- ordinary expiration. Breath-force chiefly depends upon the strength of the respiratory muscles, the mobility of the thorax, and the elasticity of the lungs. The important share the last two factors take in the result is shown by the fact that in young and slender subjects, with very elastic lungs and very mobile chests, it has generally a high relative value. It should here be observed that there is no relation between breath-force and vital capacity ; the former may be great while the latter is small, and vice versa. The Breath-Force in Disease. — In emphysema expiratory force is always diminished in relation to inspiratory. In moderate degrees of this disease the latter is normal, while the former is slightly defective. When dyspnoea begins, the falling away of expiratory force is more marked, and it may actually become less than the inspiratory, continuing to diminish as the disease advances till it may even sink to the level of one -third of the inspirator}^ force. This latter, for the most part, continues at the normal, though it may rise above this, owing to hypertrophy of the inspiratory muscles. In the last stages of the disease inspiratory power may sink below the normal, but it always remains greater than the expiratory. The modification in breath-force observed in emphysema is doubtless partly due to loss of pulmonary suction (which works against the inspiratory and with the expiratory movements), and partly to the contracture of the inspiratory muscles, and the consequent interference with the expira- tory movement. In phthisis, pleurisy, and pneumonia, inspiratory power is diminished. Expiratory power is also diminished, but remains greater than the inspiratory, though in some cases of pleural effusion it may sink below it. 46 RESPIRATORY EXERCISES In bronchitis there is deficient expiratory force, as in the first stage of emphysema. This deficiency is observed both in the acute and chronic forms, in the latter case even when micompHcated by emphysema. In spasmodic asthma there is similar expiratory de- ficiency, and this though pulmonary elasticity may not have suffered. Obstruction in the larynx and trachea diminishes in- spiratory force chiefly or solely. In scoliosis and kyphosis inspiratory and expiratory force are both defective, but especially the former. Fever leads to a deficiency in both, but chiefly in the expiratory force, these changes being due to the defective muscle-power and pulmonary elasticity induced by the febrile state. Relative Strength of the Inspiratory and Expiratory Muscles, — We have seen that inspiratory and expiratory force do not respectively represent the strength of the inspiratory and expiratory muscles. It has even been contended that the inspiratory muscles are the stronger, though I am not aware that this is capable of proof. They are the more constantly in action, and, from the respiratory point of view, the more important, seeing that expiration can take place without muscle action, while inspiration is wholly dependent upon it ; even in the extraordinary breathing induced by breathlessness, the action of the inspiratory muscles vastly preponderates over that of the expiratory. In spite of this, the expiratory muscles, which chiefly consist of the great abdominal muscles, are very powerful. Their great strength, however, is not primarily for the purpose of extraordinary expiration, but has quite other ends, such as fixing the chest, rendering the skeleton rigid during effort, and increasing intra-abdominal tension during defalcation, etc., in all of which actions the glottis is INSPIRATORY AND EXPIRATORY FORCE 47 closed and expiration prevented. It should further be observed, in this connection, that when extraordinary breathing is resorted to for physiological purposes, the abdominal muscles are never called into full play. Seldom, if ever, does the individual need to expire beyond the limit of ordinary expiration ; in great breathlessness he does not even expire thus far, the increased range of respiratory movement which then occurs being due to increased depth of inspiration. It is very seldom, in fact, that the ' complemental ' air is got rid of, and that the great abdominal muscles are called upon to contract the chest to the utmost. There can therefore be no doubt that the amount of muscle-force spent in effecting the inspiratory movements, not only of tranquil but also of extraordinary breathing,* is vastly in excess of that employed in effecting the expiratory move- ments, and that if the expiratory muscles are more powerful than the inspiratory, it is because these muscles need great strength for other purposes than expiration. Special mention may here be made of the strength of the diaphragm. This is a very powerful muscle. I am acquainted with a man who can actually move a grand piano by means of it, and I have often been struck with the extraordinary strength it displays in disease. Even in the last moments of life, when the belly has been tightly distended with fat and ascitic fluid, I have observed — and that in an old woman — considerable al)dominal movement, testifying to the strength of this muscle. Exercises for strengthening the respiratory muscles are given in Chapter XX. * I refer here to the extraordinary breathing required for the ordinary physiological purposes of life. Wlien an individual volun- tarily expu-es to the utmost, as in blowing into the spirometer, the expiratory muscles are brought into considerable play ; but such an expiration is, so to speak, ultra-physiological. CHAPTEE VIII. THE RESPIRATORY FORCES. While inspiration is essentially active, expiration, unless forced, is almost entirely passive, the only muscles taking part in it being the internal intercostals, triangularis sterni, and possibly also in very slight measure the abdominal muscles. The passive forces of tranquil expiration are the suction of the lungs on the ribs and diaphragm, and the positive intra-abdominal pressure which tends to force the diaphragm upwards directly the latter ceases to con- tract. In the upright position gravity also comes into play as an expiratory force by pulling the ribs down. These passive expiratory forces are, of course, greatest after an extraordinary inspiration, for the elastic recoil of the lungs is then increased, and, moreover, is supplemented by that of the thoracic cage, and in the vertical position of the trunk the influence of gravity also — especially if the shoulders and chest are bulky — is considerably augmented. In the fullest possiljle inspiration, however, one of the passive expiratory forces — i.e., the positive intra-abdominal pressure — is diminished. In forced expiration the expiratory recoil is helped by the contraction of special expiratory muscles — the abdominal muscles, quadratus lumborum, serratus posticus inferior, erectores spinse, and others. THE RESPIRATORY FORCES 49 Passive recoil plays very little part in inspiration. In tranquil inspiration the ribs, which during expiration have been bent inwards beyond the neutral point, recoil out- wards, and after an extraordinary expiration this outward recoil is, of course, much increased. Inspiration being essentially active, we have next to inquire. What are the muscles engaged in the act '? They are : (1) those which raise the ribs, and (2) the diaphragm. 1. In ordinary inspiration the ribs are raised by the external intercostals, the levatores costarum, and the diaphragm.* The action of the intercostals is assisted by the comparative fixity of the first ribs, which are attached by especially strong cartilages to the sternum, which, again, is supported by the clavicles. Hence, the first ribs afford purchase to the intercostal muscles below, and they are further fixed during inspiration by the contraction of the scaleni. In extraordinary inspiration many other costal elevators come into play. These include all those muscles which directly raise the ribs, such as the serratus posticus superior (which passes from the spine to the second, fifth, and inter- vening ribs), the cervicalis ascendens, and (when the arm and shoulder are fixed) the serratus magnus, the pectorals, and that part of the latissimus dorsi which passes from the humerus to the last three ribs, and also those capable of raising the clavicles and scapulae, such as the sterno- mastoids, the trapezius, and the levatores anguli. scapulae. The various costal elevators can act independent!}', especially after practice, being thus able to raise a limited set of ribs more than, or even quite independently of, the others. Thus, it is possible to expand the upper part of the thoracic cage more than the lower, or vice versa, and tp raise the ribs on one side more than on the other.f * See p. 51. t See p. 58. 50 RESPIRATORY EXERCISES 2. The diaphragm arises from (a) the back of the ensiform cartilage ; (h) the inner surface of the lower six costal cartilages, and sometimes from part of the corre- sponding bony ribs ; (c) the internal and external arched ligaments, extending respectively from the body of the second to the tip of the transverse jprocess of the first lumbar vertebra, and from the latter to the last rib ; (d) the bodies of the first three lumbar vertebrae as the two fleshy crura. From this origin its fibres pass to the central tendon, the most anterior, especially those coming from the xyphoid, being short and nearly hori- zontal, and thus by their contraction tending to pull the lower part of the sternum and adjacent cartilages back- wards ; while the remaining fibres arch upwards to their insertion, those arising lowest down from the sides of the chest having the steepest ascent, and — in the expiratory position of the chest — running for some distance in close proximity to the ribs. The arch of these fibres is most pronounced when they are lax, the diaphragm being then dome-shaped, owing to its being thrust upwards by the excess of pressure on its under surface over that upon its upper. When they contract the dome flattens out, the thorax being thereby enlarged vertically ; at the same time the central tendon and lower ribs are dragged upon, the former being somewhat depressed and the latter raised. The central tendon is prevented from any considerable descent by its connection with the pericardium, which is continuous with the cervical fasciae ; the lower ribs are, moreover, under ordinary circumstances steadied during diaphragmatic contraction by the quadratus lumborum and serratus posticus inferior. When the diaphragm contracts under these conditions, the chief effect is a straightening of its arched fibres— i.e., a flattening of the dome — the ribs being only slightly raised. I find that the girth of the THE RESPIRATORY FORCES 51 lower chest is only increased half an inch after a full diaphragmatic breath, while that of the belly is augmented by 2 inches. By practice it is possible to prevent any raising of the ribs during diaphragmatic contraction, in- spiration being then purely abdominal, a term which is not synonymous with diaphrafimatic as applied to breathing. When, however, the diaphragm is firmly sup- ported on its under surface, as happens when the abdomen is voluntarily retracted or firmly compressed, the chief effect of its contraction is to elevate the lower ribs, and thus to open out the costal arch and increase the girth of the lower chest * This expansion of the lower bony chest is, however, not solely due to the upward drag of the diaphragm upon the ribs. Some descent of this structure occurs even when it is firmly supported from below, and this tends to thrust the abdominal viscera downwards ; but their downward move- ment being checked by the firm pressure upon them of the abdommal walls, the lower ribs are bulged outwards. That the tendency of the diaphragm to elevate the lower ribs increases with the resistance which the anterior abdo- minal walls oppose to the viscera can be shown by a very simple experiment. Let the hands rest on the side of the lower chest, and then take a full diaphragmatic breath. It will be found that the hands suffer very little movement. Now, keeping them in the same position, stand facing a wall, and while pressing the abdomen firmly against it take a similar inspiration ; the lower chest will then be found to bulge very appreciably on either side. On the other hand, when the abdomen is opened, and the support on the under surface of the diaphragm thus greatly diminished, it no longer acts as a costal elevator. * It is, as we shaU see, to this end that some teachers of singing advise that the belly should be retracted during inspiration, and that others advocate the use of an abdominal belt during singing. 4—2 52 RESPIRATORY EXERCISES I have said that the central tendon is only capable of limited movement in respiration. Its range of movement is a point of some interest, because it is evident that the heart must move with it. When a deep thoracic inspiration is taken, the heart can quite plainly be felt beating in the epigastrium, and this was thought by Sibson to prove an actual downward movement of the central tendon ; but the epigastric pulsation under these circumstances might very well be due to the lifting upwards of the thoracic cage over the heart rather than to an actual descent of the heart within the thorax. In order to ascertain whether the heart descends, we should measure the vertical distance between the chin and the apex of the heart before and after a deep thoracic breath, and applying this test I do not get any evidence that the central tendon descends. It is otherwise, however, when a full diaphragmatic breath is taken icith fixed clavicles; the central tendon and the heart then actually descend, as may be shown by means of Eontgen rays. The respiratory centre is automatic. It consists of an inspiratory and expiratory portion, the former alone acting during ordinary breath- ing. The automatic action is remforced by impulses ascending the vagi from the lungs ; the expansion of the Imigs tends to inhibit through these nerves the inspiratory centre, and to excite the expnatory centre ; and, on the other hand, the contraction of the lungs tends to check the action of the expiratory centre and to incite the inspiratory centre. JMost of the vagal fibres passing to the respiratory centre act upon its inspiratory portion, and the effect of the impulses ascending them is to quicken breathing ; these fibres are in constant action. A smaller number, especially those belonging to the superior laryngeal nerves, act upon its expiratory portion. Hence it is that irritation of the larynx causes violent expiratory efforts. Impulses ascending these fibres tend to slacken the respirations. \\'hile the respiratory nerves ^;«7' excellence are the respiratory portion of the vagi, numerous afferent nerves are capable of affecting the respiratory centre. Witness the effect of cold suddenly applied to the back. THE llESPIRATORY FORCES 53 Not only is this centre influenced through the nerves, but also by the plasma bathing it. Apncea is due to impulses ascending the vagi, and not to altered plasma, while dyspna'a is essentially due to the latter. 1 n tliis condition the blood is deficient in O and surcharged with CO.^, but the excess of the latter plays only a small part, as compared with the deficiency of O, in causmg the peculiar breathing of dyspnoea. The quickened breathing induced by muscle exercise is due to the stinmlation of the medullary centre by certain unknown substances. The deficiency in O and the excess of COg cannot be the sole causes of tlie acceleration in this case, since such alterations in the blood tend to deepen rather than to hasten the respirations, as is shown in dyspncea. CHAPTEE IX. MODES IN WHICH THE THORAX IS ENLARGED. The thorax is enlarged by elevation of the ribs and descent of the diaphragm, the former increasing the sagittal and lateral diameters, and the latter the vertical diameter. In ordinary tranquil breathing, there is comparatively little rib movement, especially in the upper part of the thorax, respiration being chiefly abdominal. It is true that in the civilized woman the ribs, notably the upper ones, often move freely, diaphragmatic action being correspond- ingly curtailed ; but this type of breathing is not a natural sexual characteristic : it is due to the use of stays, which interfere with the free descent of the diaphragm and the expansion of the lower bony cage. In consequence of this, the cage in its upper part becomes expanded and abnormally mobile (hence the ' heaving bosom ' of the woman), while, con- trariwise, the growth of the lower chest is interfered with, its movements being correspondingly restricted. It is for this reason that, after the age of fourteen, the lower transverse diameter of the chest is less in the civilized woman than the upper, in man the reverse being the case (Sibson). While normal tranquil breathing is chiefly abdominal, the part played by costal elevation must not be neglected. The increase in thoracic girth thus affected is only 2 to 3 mm.,* but the importance of this slight increase is * Hutchinson gives 1 to 2 mm. ; Burdon Sanderson, 1 to 6 mm. ; Douglas-Powell, 2 to 3 mm. MODES IX WHICH THE THORAX IS EXLARGED 55 shown by the fact that when, as from myelitis just below the origin of the phrenics, the individual has to depend upon pure diaphragmatic breathing, the respirations are laboured.* But that the diaphragm plays the more im- portant part in tranquil breathing is evident from the great difficulty of breathing resulting from its paralysis. Costal breathing is more developed in man than in any animal. If, for instance, we examine the thorax of an anthropoid ape, we find that the sagittal diameter is nearly as long_as the transverse, and the same feature is observed in the human infant. It is clear that the capacity of such chests cannot be greatly increased by elevation of the ribs, but as the erect posture comes to be assumed, the chest flattens so as to throw the centre of gravity backwards, and thus keep it vertically above the narrow basis of support aflbrded by the feet, and in this way the capacity for costal breathing is increased. Nevertheless, as already observed, tranquil breathing is essentially diaphragmatic. This is even more the case in the horizontal position than in the upright, because the pressure of the ribs against the surface of support interferes with their movement. Even among women it will be found that m the horizontal position, when no stays are worn, tranquil breathing is chiefly diaphragmatic. The mode in which the thoracic cage expands is best studied during an extraordinary inspiration. The clavicles, scapula^ sternum, and ribs are then raised ; the anterior extremities of the clavicles and ribs move forwards and upwards, carrying with them the sternum, which at the same time tends to become convex anteriorly, or to suffer an * While writing this 1 have such a case under observation. The breathing is purely diaphragmatic and manifestly laboured, although the luugs are normal. It is, however, possible that this laboured action depends upon paralysis of the muscles which steady the lower ribs, and thus facilitate the inspiratory action of the diaphragm. 56 ' RESPIRATORY EXERCISES increase in its natural convexity, while the posterior costal extremities move backwards, carrying with them the spine. This may be easily demonstrated by placing the hand on the middle of the back while a deep inspiration is being made. The movement of the upper ribs is chiefly forwards, that of the lower ribs chiefly backwards, and Sibson points out, in connection with this fact, that the bulk of the upper part of the lungs is in front, while the bulk of the lower part is behind. The backward movement is most marked at that part of the spine which articulates with the sixth, seventh, and eighth ribs. Were the spine as movable as the sternum, elevation of the ribs would cause it to travel as much backwards as it causes the sternum to move forwards, for the ribs passing obliquely from spine to sternum, any diminution in their obliquity must increase the distance between these two. The sternum being, however, less fixed than the spine, tends to move the more, but as it approaches its limit, i.e., towards the end of inspiration, it ofiers considerable resistance to further movement, and it is then that the backward move- ment of the spine becomes most pronounced. As the ribs ascend they undergo some eversion, and this tends to increase the lateral diameter of the chest, but the increase in the lateral diameter is chiefly due to a straighten ing out of the costal curves. In the posterior movement of the ribs, their angles move backwards more than the spine, thus deepening the spaces for the lungs on either side of the spine. During costal ascent the upj^er riljs approach one another, while the distance between the remaining ribs, especially the last three, increases, as can be easily shown by placing the fingers between them. In some the upper part of the sternum moves forwards more than the lower ; in others the reverse occurs. MODES IN WHICH THE THORAX IS ENLARGED 57 Sibson has shown that the third, fourth, and fifth costal cartilages move forwards somewhat beyond the sternum. When, however, the cartilages are rigid and welded to the sternum, the latter advances more than the cartilages.* The movement of the fourth, fifth, and sixth cartilages, and of the sixth rib over the heart, is somewhat less than on the right side. This is even true of tranquil breathing. It is possible completely to dissociate costal from abdominal breathing, for though contraction of the diaphragm tends to raise the lower ribs, it is, as already pointed out, possible to check all costal movement during diaphragmatic descent. Costal breathing falls under two heads : (a) That in which the clavicles are raised, and with them all the ribs. When such an inspiration is carried to its extreme, the ribs are elevated to their utmost, and the chest cavity is increased to its maximum. I shall speak of this as the pancostal method, {h) That in which the ribs are raised without elevation of the clavicles. All the ribs may be raised in this method by allowing the inner ends of the clavicles to move forwards, but even then the chief expansion takes place in the lower part of the chest. I shall therefore speak of it as the lower costal method. There are thus three primitive types of breathing in the normal chest : pancostal, lower costal, and abdominal. Much confusion may be avoided if we keep this fact clearly in mind. The so-called clavicular variety, about which so much has been written, is, as far as I can see, impossible under normal conditions. In it the clavicles are raised and the upper part of the chest is supposed to expand alone, or at all events greatly in excess of the lower part ; but this appears to me to be absolutely impossible under normal conditions, since the lower ribs must ascend with the upper, * The tendency of the upper costal cartilages to advance beyond the sternum is often well shown in the chest of hypcrtrophous emphysema. 58 RESPIRATORY EXERCISES and this implies expansion of the lower chest. "When, how- ever, the lower part of the chest is tightly bound with a rigid corset, it is necessarily incapable of proper exj)ansion — if, indeed, of any expansion at all — and under these circumstances a costal inspiration causes an enlargement of the upper chest chiefly or only. This part of the chest undergoes in those who habitually tight-lace a compensa- tory enlargement and acquires increased mobility, and this undue mobility of the upper chest is observed in such even after the corset has been removed. I do not deny that it may be possible by practice to gain such control over the elevators of the upper ribs as to cause them to be raised more than the lower during inspiration, and thus to bring about a relatively larger expansion of the upper than of the lower chest. The Italian teachers of singing lay great stress upon this expansion of the upper chest, and advise the singer to direct to it all his attention in breathing. To this end the shoulders are held back, in order that the scapulae may afford jJoiAi^s cVapiyiii for the serrati magni, which under these circumstances become costal elevators, and there are, of course, other special elevators of the upper ribs. It must, however, be remem- bered that the lower ribs are compelled to follow the upper ones, and this necessitates a considerable expansion of the lower chest, unless the latter is compressed. This is the proper place to refer to the retraction of the lielly which accompanies a deep costal inspiration. Such an inspiration causes flattening of the belly, the upper part shelving suddenly away from the costal arch. This is especially noticeable in the epigastrium, which constitutes a pronounced hollow. Exactly the same thing is observed if, prior to the costal breath, the belly be bulged by a deep diaphragmatic inspiration : as the ribs are raised, it gradually recedes, finally becoming scaphoid. MODES IN WHICH THE THOKAX IS ENLARGED 50 This flattening or actual hollowing out of the belly is due to several causes. When the ribs are elevated to the utmost, the lungs are unable, by their fullest expansion, to fill the chest, unless the diaphragm lies high. With every increase in the size of the chest the suction of the lungs on the sides and base of the thorax increases. It is insufficient to draw in the ribs, which are held in position by powerful costal inspirators, but the diaphragm is unable to resist it, and is thus sucked upwards. So great is this suction at the end of a complete costal inspiration, that the most strenuous effort at diaphragmatic inspiration is powerless to cause any diaphragmatic descent ; and it is this suction which determines the limit of costal inspiration. Small, ill-de- veloped lungs are very soon stretched to their utmost, and therefore only permit of moderate costal expansion ; but large, well-developed lungs (non-emphysematous) permit considerable costal elevation to occur before suction puts a stop to further expansion. The eftect of the upward aspiration of the diaphragm is to mcrease the vertical diameter of the abdominal cavity ; the elevation of the costal arch acts in the same direction, and, moreover, puts the abdominal wall on the stretch, while the opening out of the costal arch augments the transverse diameter of the abdomen above. The abdominal cavity, being thus increased in its transverse and vertical diameters, necessarily suffers diminution in its sagittal diameter, this being favoured by a diminution in intra-abdominal tension. Hence a deep costal inspiration causes a flattening of the belly. The scaphoid appearance thus induced in a thin subject is rendered more pronounced by the throwing for- ward of the costal arch, which helps to cause the abdominal wall to shelve away from it, and also by the backward movement of the dorso-lumbar spine which accompanies a deep costal inspiration. The flattening of the belly just described must be care- 60 . EESPIRATOKY EXERCISES fully distinguished from that which is due to a voluntary contraction of the transverse fibres of the abdominal walls. This is the kind of retraction advocated by those teachers of singing who advise costal as distinguished from abdominal breathing. Sir Morel Mackenzie and others have mixed up these two varieties of retraction. Mackenzie assumed that the retraction of the belly observed in divers before diving, and in those about to make a strong effort, is a primary event, akin to the retraction adopted by singers ; whereas it is, in point of fact, a secondary event — the result of a deep costal inspiration. Costal and abdominal breathing may be associated. After a full pancostal breath, it is, as we shall see, doubtful whether in the normal individual any additional air can be inspired by means of the diaphragm ; the quantity must in any case be small. While, however, after such an inspira- tion abdominal breathing is, in the normal individual, practically impossible, it is, in a limited degree, possible after an incomplete inspiration of this kind. Abdominal breathing may, in a similar way, be asso- ciated with lower costal breathing, and here also the abdominal breath is limited. The fact is that expansion of the lower bony thorax causes a flattening of the dia- phragm which necessarily entrails the range of abdominal breathing. Nevertheless, lower costal and abdominal breathing may be associated in varying degrees ; thus, a complete lower costal breath may be associated with a moderate abdominal breath, and, again, an almost complete abdominal inspiration with moderate lower costal expansion. The Quantity of Air that can be expired by Different Methods of Breathing. — The total quantity of air that can be expired after the fullest possible inspiration is termed the ' vital capacity.' This subject will Ije dealt with in a separate chapter. Here it will l)e convenient to note the quantity MODES IN WHICH THE THORAX IS ENLARGED 61 of air that can be expired by the different methods of breathing. The subjoined table gives the results obtained by the spirometer in my own case. I must mention, how- ever, that it is extremely difficult to make accurate observa- tion on this head, because it is by no means easy to breathe by any particular method without encroaching on] another. Thus, in pure abdominal breathing we must be absolutely certain the ribs do not move ; the result in this case, more- over, depends upon the degree of expansion of the bony thorax while the abdominal breath is being taken.* Table showixg the Quantity of Air which can be expired by THE Different Methods of Breathing. Pancostal 400 cub. in. Lotver costal 210 cub. in. This can be extended by allowinff the inner ends of the clavicles to move upwards, and by varying the elevation of the entire clavicles. Loivcr costal, siq^plemetited htj ahdominal 210 to 270 cub. in. According to the degree of diaphragmatic descent. Ahdominal Thorax kept fixed in its mean position 110 cub. in. Thorax kept fixed in position of costal expiration 170 cub. in. Thorax kept fixed in lower costal ex- pansion 90 cub. in. Ahdominal, supplemented hy lower costal expansion 110 to 270 cub. in. According to the degree of lower costal expansion. 200 cubic inches are inspired by a full abdominal breath, making no effort to prevent expansion of the lower chest, nor to cause it, the ribs not passing beyond the mean in expiration. * For these and other reasons I cannot but receive the figures which have been published relative to this question with some reserve. To mention only one instance, JoaP gives the abdominal and costal respi- ratory capacities of tliree experienced singers as follows : Abdominal. Costal. 5,200 c.c 5,300 c.c. 4,300 „ 4,800 „ 4,000 „ 4,300 „ In the first case, that is to say, the proportion is as 52 : 53. I have no doubt whatever that in this, and indeed in all three cases, the abdominal inspiration was supplemented by a lower costal breath ; otherwise the disproportion would be very much greater. 1 ' On Eespiration in Singers,' tianslatcd by Ncnis Wolfenden, p. 80. 62 RESPIRATORY EXERCISES It will be seen from the above that pure abdominal breathing gives a very small volume of air, but that if this method is supplemented by lower costal inspiration, as it practically alwa3'S is, it may give as large a volume as the latter method. It will also be observed that the quantity of air that can be inspired by descent of the diaphragm, i.e., by abdominal breathing, varies according to the degree of expansion of the lower bony chest. The more expanded this is, the nearer are the circumferential attachments of the dia- phragm to the level of the central tendon — i.e., the flatter is the diaphragm, and the less is its inspiratory power. Contrariwise, the more contracted the lower bony chest, the more arched is the diaphragm and the greater its inspiratory power. Hence I find that when my thorax is fixed in full lower costal expansion I can only inspire 90 cubic inches by descent of the diaphragm, while by the same means I can inspire nearly double the amount (170 cubic inches) when it is fixed in a position of extreme costal expiration. When it is fixed in the mean position 110 cubic mches can be taken in by an abdominal breath. The 170 cubic inches represent the amount that can be inhaled when the circumference of the diaphragm is lowered down to the fullest possible extent below the central tendon, when that tendon is arched to its utmost, and when, therefore, the greatest increase in thoracic capacity can l^e effected by its contraction. The 90 cubic inches represent the quantity of air that can be inspired when the diaphragm is flattened by the extreme opening out of the costal arch and thus rendered less capable of increasing thoracic capacity. If, after a complete expiration, a full diaphragmatic breath be taken, it will be found that it is still possible to take in a large draught of air. The same is true if a lower costo-diaphragmatic breath be taken instead of a diaphrag- MODES IN WHICH THE THORAX IS ENLARGED G3 matic, though in this case the amount of air that can be subsequently inhaled is less. If, on the other hand, a full pancostal inspiration be taken after a complete expiration, no more air, or at all events only a small quantity, can be inhaled by means of the diaphragm.* In other words, the lungs in the normal individual are not large enough to fill the thorax at its potential maximum, i.e., with the ribs elevated and the diaphragm depressed to their respective extremes. I say in the normal individual, by which I mean one with freely movable ribs and healthy lungs. If the ribs are not freely movable, so as to allow of a deep costal inspiration, the individual may be able to take an appre- ciable abdominal breath after he has raised the ribs to the utmost. Similarly, in large-lunged emphysema, the lungs may be large enough to admit of considerable abdominal breathing after a full pancostal inspiration. f * This at once disposes of the view, held by some teachers of sing- ing, that more air can be taken in by a diaphragmatic or lower costo- diaphragmatic breath than by the purely costal method. Fm-ther proof of the fallacy of this teaching is supplied b^- the spirometer. t It has been suggested to me that the lungs are large enough to fill the chest when expanded to its potential maximum, and that the inability to take in an ample supply of air by means of the diaphragm, after a full costal inspiration, is not due to the lungs having been stretched to their limits, but to the diaphragm having been flattened to the utmost by the lower costal expansion. I cannot accept this view. Air can be inspired when the costal arch is opened out to its utmost by a lower costal inspiration. In emphysema, again, the bony chest may be in a state of superextraordinary inspiration, and the diaphragm yet retain considerable inspiratory power. It is true that in very advanced cases of hypertrophous emphysema the respiratory capacity of the diaphragm is greatly curtailed, and may possibly in some cases be quite annulled. Nevertheless, if we except such, I beUeve that the potential capacity of the chest is always greater than that of the lungs, and that the expansibility of these organs essentially determines the limit to which the thorax can be enlarged. This position is strengthened by what we observe in destructive puhuonary disease, which alway diminishes thoracic expansibility. CHAPTER X. BREATHING IN SINGERS. The various methods of breathing which have been recom- mended for singers are not always very lucidly expounded, but they may, I think, be described under one or other of the following heads : 1. Clavicular ; when the clavicles are raised, and the expansion in the upper part of the chest is in relative excess, 2. Pure lower costal: when the lower ribs are raised, without any protrusion of the belly, the clavicles being kept fixed. A sub variety of this is that in which the inner ends of the clavicles are moved upwards and forwards, thus securing an increased expansion of the upper part of the chest. 3. Lower costo-abdominal : when the lower ribs are raised, and the belly protruded, the former being the essential movement. 4. Pure abdominal : when the belly is protruded, the ril)S Iteing fixed. 5. Abdomino-costal : when the l^elly is protruded, and the lower riljs raised, the former being the essen- tial factor. 1. Clavicular Breathing. — In this the clavicles are raised, and the expansion of the upper part of the chest is in relative excess.* * Nothing better shows the obscurity which prevails regarding the various modes of breathing for singers than Joal's observations on clavicular breathing. See on this subject the author's paper in the Journal of Laryngology, etc., 1897, p. 35. BREATHING IN SINGERS 65 This mode of breathing is practically impo8sil)le for a man, but many women are undoubtedly, in the sense defined abo\e, clavicular breathers, because the lower chest cannot expand adequately when the stays are worn tight. The quantity of air they inspire by this method is said to be less than by the others. In men, on the other hand, raising the clavicles necessitates a considerable expansion of the entire bony chest, not of the upper part only, and so it secures the maximum intake of air ; but this is not the classical clavicular breathing. It might be described as the pancostal type. I conclude, however, that, under whatever name, it is the method adopted by singers of the old Italian school, for some of them executed passages exceeding ninety-five seconds, and I do not think it probable that any man could execute so long a passage in one breath except by the pancostal method, i.e., by raising the clavicles and all the ribs to the utmost. Joal, however, is of the opinion that this school adopted the lower costo-abdominal method. 2. Lower Costal Breatking. — In this the clavicles are kept fixed, and the ribs are raised, expansion taking place chiefly in the lower part of the chest, the diaphragm not descending- This is the method, so far as I can understand, described by Mayo Collier, and recommended by him and by the late Sir Morel Mackenzie, though they are silent as to whether the clavicle should be raised or not. In this method the abdomen is drawn in (' rendered con- cave ') by a contraction of the abdommal muscles, and it is argued that thereby ' the vault of the diaphragm is sup- ported by the front abdommal walls, and maintained in position by the liver, spleen, and great end of the stomach ' (p. 94). In this way the central tendon of the diaphragm is fixed, and the contraction of the muscle fibres which pass more or less vertically from the central tendon above to the 60 RESPIRATORY EXERCISES ribs below, spends itself in raising the lower ribs, and in expanding the lower bony thorax. It should be observed that a very slight elevation of the clavicle during a lower costal breath adds considerably to the volume of air that can be inspired, and there can be no doubt that many singers who for the most part adopt the lower costal method, and who would indignantly repudiate the accusation of being clavicular breathers, do appreciably elevate the clavicles, especially when desirous of taking a more than usually deep breath. 3. Lower Costo-Abdominal Breathing. — In this variety the lower costal breathing is combined with varying degrees of abdominal breathing, but the latter is subsidiary to the former, and only occurs in comparatively slight degree, causing a moderate protrusion of the epigastrium. It should be mentioned that some degree of epigastric protru- sion is apt to occur whenever a deep costal inspiration is taken. This may result from two causes : either from an active descent of the diaphragm, or from an elevation of the lower end of the sternum above the central tendon of the diaphragm, causing the heart to lie immediately under the epigastric wall. This, as I understand him, is the method of breathing advocated by M. Joal, though he does not make it abso- lutely certain whether he recommends actual descent of the diaphragm, merely remarking that ' the convexity of the diaphragm tends to be effaced.'* The belly, he con- tends, should be retracted in the subumbilical region, and while the clavicles are kept fixed the ril)s are elevated to their fullest extent and the epigastrium protruded (pre- sumably from active descent of the diaphragm). The retraction of the subumbilical region he refers to a volun- tary contraction of the inferior fasciculi of the abdominal * *0n Respiration in Singers,' translated by Norris Wolfenden, p. HO. BREATH IXG IN" SINGERS * ()7 muscles (p. 117),* and its object is to support the dia- phragm below, so as to enable the entire force of its con- traction to be devoted to the elevation of the lower ribs, as already described. To the same end some singers com- press the belly by means of a band or belt. This form of breathing Joal somewhat ambiguously designates the ' costal ' type, and he gives it his enthusiastic support. In it he assumes the upper ribs to be stationary ; but it is certain that fixation of the clavicle by no means prevents expansion of the upper chest, as anyone may see for him- self who will examme the bare chest while a full costal breath is being taken with fixed clavicles. It is contended by Joal that this method of breathing secures a larger volume of air than the others by expand- ing the chest in its most roomy part. This is not my experience. A method of breathing taught in Italy and described by Cathcart may be mentioned here, in that it is allied to Joal's method. The outer ends of the clavicles are fixed, the inner extremities moving upwards and forward. In this way not only is the superior entrance to the thorax enlarged, but the bony chest is enabled to expand amply in its upper as well as in its lower part. Indeed, what is aimed at is producing the maximum expansion above. 4. Pure Abdominal Breathing. — In this the breathing is, as far as possible, purely al)clominal ; i.e., the diaphragm •contracts with relaxed abdominal walls, and being thus only slightly supported on its under surface, the force of its con- traction is chiefly spent in thrusting the abdominal viscera downwards, and in increasing the vertical capacity of the * It is due, I believe, to a contraction of the transversely disposed muscle fibres of the anterior abdominal wall, as already described ; a contraction of the lower portions of the recti would tend to pull down the ribs and sternum, which are requu-ed to be raised in the form of breathing under discussion. 5-2 68 RESPIRATORY EXERCISES chest, and to only a small extent in an upward tug on the ribs (which are probably prevented from being raised by a con- traction of certain muscles, such as the quadrati lumborum and the serrati postici inferiores). At all events, while con- traction of the diaphragm tends to raise the ribs, even with relaxed abdomen, there can be no doubt, as Mandl observes, that ' when the person is completely master of diaphragmatic respiration, deep inspirations can be taken without elevating the ribs in any manner, as Magendie had already said.'* Abdominal breathing is closely associated with the name of Mandl, who in 1855 advocated this mode of breathing in an article which appeared in the Gazette Medicale, though it had already been largely practised. He obtained a wide following, and in schools of singing most strange devices were resorted to for the purpose of fixing the ribs and compelling pure abdominal breathing ; thus, the * pupils were made to sing while lying down on mattresses, sometimes with weights, more or less heavy, placed on the sternal region ; masters were even said to make a practice of seating themselves familiarly upon the chests of their pupils. In the schools were to be seen gallows with thongs and rings for binding the upper half of the body, orthopnidic apparatus, rigid corsets, and a kind of pillory which enclosed the frame and fixed the ribs.'t Abdominal breathing is said to be rarely employed by women. Joal has not met with a single woman singer who adopts this method. Nor is this surprising, when we reflect that the corset interferes with the abdominal protrusion. But, indeed, this method is probably very rarely employed at all — I doubt if it ever is, pure and simple. I cannot believe that Mandl and his school confined themselves tO' pure abdominal l>reatliing. * Joal, o^j. clt., p. 67. t Ibid., p. 43. BREATHING IX SINGERS 69 5. Abdomino-Costal Breathing^. — When abdominal is supple- mented by costal breathing, -we may term it' abdomino-costal.' It is the method recommended by Lennox Browne and Behnke in their work on ' Voice, Song, and Speech.' I now propose briefly to criticise these various modes of breathing, with a view to discover which is the most suitable for the singer. I must at once confess that I do not at present see my way to recommend very specially any one method to the exclusion of the others. What I have been most concerned to do is to define accurately the different modes in which breathing may be carried on, and to clear the ground for profitable discussion. Practically, all writers condemn forced clavicular breathing in the case of the man, but there are some who justify its employment in the woman, on the erroneous assumption that it constitutes for her the normal type of breathing. Its evils are self-evident, necessitating as it does elevation of the shoulders, and, from the contraction of the cervical muscles, compression of the important structures entering the thorax from above. The effort of lifting with every inspiration the entire thorax and upper extremities is tiriag.; the interference with the return of blood from the head during a loud and long-sustained note may be so great as to cause t_urbidity^ and even duskine ss, of the face ; and it is, moreover, doubtful whether expiration can be so nicely regulated as by the other methods. If pronounced clavicular breathing is ever justifiable, it should certamly only be^ mployed on rare occa sions, a nd as an extension of the more usual form of breathing. It is otherwise, however, with modified clavicular breathing. I can see no objection to a moderate upward and forward movement of the inner ends of the clavicles, as recom- ' mended by Cathcart. This not only enlarges the superior 70 RESPIRATORY EXERCISES opening of the thorax, but favours the expansion of the upper portions of the chest, where, it is contended, ample expansion should be aimed at on the ground that the nearer the resonating cavity is to the seat of voice-produc- tion, the better resonance does it give. It is certain that moderate clavicular breathing is frequently emploj^ed by those who claim to be lower-chest breathers, and it seems at least doubtful whether the singer should rigidly adhere to the hard and fast rule never to raise the clavicles in the slightest degree. Accepting, then, the dictum that pronounced clavicular breathing can only be justifiable on rare occasions, we have to inquire which of the other methods is the best. Is it (a) the pure lower costal ; or (h) this extended by abdominal breathing (and if this form, how much abdominal extension is justifiable) ; or (c) the pure abdominal ; or, finally, (d) the abdominal, extended by the lower costal (and if the latter form, how much lower costal is justifiable) "? In seeking an answer to our question, we of course attach some weight to the amount of air that can be inspired by the various methods, but not too much. The singer is not required to distend his chest to the utmost.* Were a large volume of air the great desideratum, then a pancostal breath, with extreme elevation of the clavicles, would be best, for by it half again as much air can be inspired as by any other method. It is urged that the lower costo-abdominal method is superior to the abdominal, in that the work is shared by a larger number of muscles, for in abdominal breathing these are more or less confined to the diaphragm and the abdominal muscles. Speaking from my own experience, I should say that the very reverse is the case : an abdominal breath can * Joal argues as if it were necessary to take in a ^•cry large volume of air. Sec op. cit., pp. 72, 80, 134. BREATHING IN SINGERS 71 be taken with the utmost ease, while a lower costal breath involves an appreciable effort, seeing that the ribs have not only to be raised but also to be bent. It is also argued that in the abdominal method expiration requires the expenditure of more energy than in the lower costal variety, in order to push up ihe viscera, which are displaced downward by the descent of the diaphragm — an argument of no weight, seeing that these organs are capable of resuming their normal position upon mere relaxation of the diaphragm without any contraction of the abdominal muscles, being drawn up by the elastic recoil of the lungs. We have next to inquire whether the abdominal or the costal method enables the singer to regulate the outgoing blast of air with the greater precision and nicety. The air, as we know, has to be driven out slowly, steadily {i.e., without jerks), and with varying degrees of intensity. How is this regulation effected ? Cathcart contends that in the case of costal breathing it is, or should be, effected by the mutual antagonism between the expiratory muscles and the false vocal cords, which approximate in order to oppose the outgoing blast of air, and he attaches great importance to this laryngeal impediment, seeing that with- out it (so he argues) it would be impossible to get that degree of condensation of pulmonary air necessary to bring out the best quality of tone. It is, however, more generally held that the regulation of the expiratory blast is essentially dependent upon the antagonistic action of the inspiratory and expiratory muscles, and this is probably the ease in abdominal and in pronounced clavicular breathing. Cathcart holds that, in the form of breathing he recom- mends, the inspirators cease to contract when expiration begins, the air being held by the false vocal cords ; but according to the prevailing view the inspirators continue in action, though with diminishing force, throughout the entire 72 RESPIRATORY EXERCISES period of expiration, no matter what mode of breathing is adopted. Of the two sets of muscles, however, it is held that the expirators act the more powerfully, and thus expel the air, the force of expulsion and consequent loudness of note depending upon the degree of excess of inspiratory over expiratory action. In delivering a note fortissimo, for instance, the expirators act with full force, the inspirators undergoing considerable relaxation.* Now, it is urged that much better control can be exercised over the expiratory blast by the costal than by the abdominal method, which, according to Cheval, Morel Mackenzie, and others, is apt to give a jerky note, from the inability of the diaphragm to undergo a gradual and even relaxation. This is, of course, a question for experience to decide, but I see no theoretic reason why the diaphragm should not be taught to relax gradually as well as other muscles. Indeed, this argument regarding the inability of the diaphragm to undergo gradual and even relaxation may be employe(J against the lower costal method, seeing that the supporters of it contend that the diaphragm is an important agent in expanding the lower bony chest. Cathcart contends that by his method the air is driven out of the lower regions of the langs faster than from the upper lobes, and that 'the upper ribs will only be pulled down when the lower lobes are nearly exhausted, and it is then time to renew the breath.' In this way, he argues, the high resonating properties of the expanded upper chest are maintained throughout expiration. I have not yet had the opportunity of testing the accuracy of this view; I will only here observe that the upper ribs must to a large extent follow the lower. It has been further urged that abdominal breathing may induce serious disturbances in the abdomino-pelvic * .Joal, op. cit., p. 97. BREATHING IN SINGERS 73 viscera. In this method the diaphragm descends to its furthermost limit, and remains contracted throughout nearly the entire period of expiration, during which time the abdominal muscles are contracted also, in order to expel the air. This leads to considerable compression of the abdominal and pelvic organs, and, according to Cheval,* all sorts of troubles may thus result, such as hernias, indigestions, and disorders of the abdominal circulation. Joal describes the case of a woman at twenty-two, who was in perfect health and ' able to sing with impunity up to the day when she fell into the hands of a fanatical professor of abdominal respiration,' after which dysmenorrhoea, which was found to depend upon retroversion of the uterus, set in (p. 74). In another case the most violent form of dyspepsia was similarly induced. He quotes from other authors to the same effect, and refers to a case of uterine prolapse as resulting from the abdominal method of breathing. Now, I can quite understand that this form of breathing might bring al)out some of these evils in women who tight-lace, but I find it hard to believe that it can be injurious to the normal woman who does not compress the waist and abdomen. A further argument has been advanced in favour of costal breathing, whether the lower costal, as advocated by Joal, or that more extended form recommended by Cathcart, in which the upper chest is well expanded, i.e., that it increases the resonance of the bony thorax ; and if such is the case, it should go a long way to turn the balance in its favour. I am aware that theoretic considerations appear to support this view, and it is said to be borne out by practical expe- rience, but I should like definite proof of this. One word as to the desirability of voluntarily retracting the belly in lower costal breathing. I confess I am some- * Joal, p. 74. 74 RESPIRATORY EXERCISES what doubtful as to the utility of it. I think it highly doubtful whether the diaphragm plays an important part in elevating the lower ribs in this type of breathing. In my experience the ribs can be equally well raised with flaccid belly. It does not seem to me improbable that abdominal retraction was originally advocated in order to render abdominal breathing impossible. Note. — In response to a request, my friend Dr. George C. Cathcart has briefly set forth his views regarding the proper method of breathing for smgers : ' Breathing for singing differs from ordinary breathing in that the chest has to be used not only as a reservoir for the air which vibrates the vocal cords, but also as a resonator of the voice. When we remember that the effectiveness of a resonator increases with its nearness to the sound it resonates, it will at once be seen what an important part the mode of breathing plays in proper voice production. The abdominal method originally introduced by Mandl makes no use of the chest as a resonator. This method, combined with lower costal, as advocated by Brown and Behnke, is little better, as it also ignores the use of the chest as a resonator. In the old Italian method the chest was raised , as a whole, every effort being made to cause the maximum expansion of the upper part, the inner ends of the clavicles being raised and the abdomen retracted. In this waj^ not only can a large volume of air bo taken in, but the resonator is brought as near as possible to the vocal cords. This method is in accordance with nature, science, and art.' CHAPTER XL VITAL CAPACITY. ' ^'ITAL CAPACITY ' IS the term which John Hutchinson employed to denote the amount of air that can be expired after the fullest possible inspiration. After testing the vital capacity of a large number of individuals, he estimated its average for persons 5 feet in height at 174 cubic inches, with an increase of 8 cubic inches for every inch above this. Arnold's estimate for 5 feet is about the same, but he gives the increase for every inch in height above this as about 94- inches. Hence, according to Hutchinson, a man of 6 feet should breathe 270 cubic inches, while according to Arnold it would be 288 cubic inches. This relation between height and vital capacity is remark- able, since height is determined chiefly by length of legs, and not by the size of the trunk and the thorax. People of 5 feet inches in height and those of 6 feet have much the same length of trunk, and therefore the same length of thorax ; nor is there necessarily any increase in the chest circumference with increased height. Indeed, short men have often much greater thoracic girth than tall men. Hence, there is no necessary relation between chest capacity and height, but between vital capacity and height there practically always is.* This is due to the fact that the mohiliti/ of tJtc chest increases iritli the stature. * Hutchinson determined the cubical contents of the thorax by removing the heart and lungs through an opening sufficiently large to 76 RESPIRATORY EXERCISES Hutchinson further held that there is also no relation between the circumference of the chest and vital capacity, a tall man with a chest of 34 girth probably having a larger vital capacity than a short man with a 40 inch. But of course, with equal mobility, the greater the circum- ference, the greater the vital capacity. Arnold, on the other hand, finds a definite relation between thoracic girth and vital capacity. He gives 160 cubic inches as the standard capacity of a thoracic girth of 26 inches, and 9 inches the increment in capacity for every increase of 1 inch in girth. Other formulae are given by which it is claimed that the normal vital capacity of an mdividual may be calculated. Thus, Wintrich has sought to find a coefficient which, multiplied by the height, should give the normal vital capacity ; C. W. Miiller calculates it from the length of the trunk and the circumference of the chest, and Arnold from the total height and the circumference of the chest. All such formulae are untrustworthy. For the same height the vital capacity is much less in women than in men. Waldenburg estimates the former at from three-quarters to two-thirds that of the latter, and Arnold found the increase with every inch of stature as two- thirds that of men. According to Wintrich, vital capacity goes on increasing up to the age of forty ; according to Arnold, up to thirty- five. Hutchinson found an increase up to thirty, and a diminution of 1^ inches with every subsequent year up to sixty. In old age vital capacity sinks to a very low level. admit the hand, and subsequently injecting it with plaster of Paris. In this way he was able to obtain a cast of the chest, the cubical con- tents of which could then be readily ascertained, and by this means he claimed to show that vital capacity may be larger than the mean cubical contents of the chest. VITAL CAPACITY 77 Those leading sedentary lives have a much smaller vital capacity than the active. It is, indeed, surprising how fixed the chest becomes in the sedentary. Vital capacity is greater in the standing than in the sitting posture, and greater in the latter than when lying down. It is diminished by obesity, after a heavy meal, by pregnancy, and all other conditions curtailing the respiratory area or interfering with the respiratory movements. The Practical Value of gauging Vital Capacity: Value in Diagnosis. — Spirometry is practically useless in diagnosis where other means have failed, though Hutchinson claimed by this means alone to have diagnosed a case of com- mencing phthisis. All tables which claim to give the normal vital capacity for different heights and different chest measurements are approximate only ; at best they can only give an average quantity — a standard which, however correct it may be as the mean capacity of a large number, does not necessarily give us the normal capacity of the individual. Individual capacities vary on either side of this mean. Hence, one with healthy lungs may fall below it, while one with pulmonary disease may surpass it. If we possessed a record of the normal vital capacity of the individual founded upon spirometric examinations, the case would be different ; then any decided falling away from this would unmistakably indi- cate disease. But while spirometry is useless for diagnostic purposes, it is of value for ascertaining the extent and the progress of disease. If, for instance, the vital capacity in a case of phthisis is good, we know that there cannot be great destruc- tion of tissue ; and, similarly, the degree of emphysema present can be estimated with considerable accuracy. Waldenburg points out that when the emphysematous patient can breathe decidedly more into a chamber of 78 RESPIRATORY EXERCISES rarefied air than into ordinary air, the prognosis is l)etter than when such is not the case. Spirometry is also decidedly useful in indicating the effect of treatment. By its means we are able to record accurately any increase in the expansibility of the lungs or the mobility of the chest. The Quantity of Residual Air. — The air which remains in the lungs after the fullest possible expiration is termed the ' residual ' air. Hutchinson estimates it at from 30 to 60 cubic inches, Vierordt at from 30 to 40. Waldenburg believes it to be much more than this — to be, indeed, nearly, if not quite, double the vital capacity. He points out that several pints of fluid may be drawn off from one pleura, even when the lung on the same side is by no means entirely collapsed, and when the other lung is quite un- affected. Apparently, however, he overlooks the fact that when a pleura is distended with fluid the corresponding side of the chest is in the inspiratory position, and not in that position in which the lungs contain residual air only, i.e., the position of expiration. CHAPTER XII. SECONDARY EFFECTS OF THE RESPIRATORY MOVEMENTS. There is a tendency to think of the respiratory movements as subserving one function only, namely, the aeration of the blood. The fact is, however, far otherwise. In tlie first place, the circulation of blood and lymph is pro- foundly affected by the thoracic movements ; in the second, several important organs are rhythmically commoted, and their functions thus influenced in no small degree. These latter effects I will now briefly describe. During diaphragmatic descent all the movable abdominal and pelvic viscera are pushed downwards, their dislocation during deep abdominal breathing being considerable.* This may be proved l)y placing the palm of the hand upon the perinteum and then taking a deep inspiration, when a descent and increasing fulness of the perinseum can be felt quite plainly ; a sudden cough produces a strong impulse in the same situation. The extent to which the liver * Sibson writes that, as a result of diaphragmatic descent, ' the liver, stomach, spleen, pancreas, kidneys, and all the abdominal organs, the uterus (the inspiratory descent of which has been felt by Dr. Frederick Bird), and all the pelvic viscera, are pushed downwards during a deep inspiration ; at which time the permaeuni protrudes more tlian it does in the tranquil state' {Med. Chir. Traus. , xol. xxxi., p. 363). I am not, however, aware that there is any proof that the kidneys and pancreas descend during inspiration. 80 RESPIRATORY EXERCISES descends in breathing has ah'eady been referred to, and there can be no doubt that these movements favour its functional activity by hurrying on the flow of blood, lymph and bile. The liver is, during inspiration, squeezed between the diaphragm — which grasps a considerable portion of its large convex surface — and the anterior abdominal wall, and it is manifest that this rhythmical compression must pro- foundly modify the hepatic functions. We must, indeed, assume that the functions of the abdomino-pelvic viscera are dependent for their normal activity upon this rhythmic compression and dislocation, so that any interference with the latter must injuriously affect the former. The descent of the diaphragm causes a corresponding downward movement of the heart. ' The central tendon of the diaphragm, forming the floor of the pericardium, pre- sents an inclined plane, upon which the heart glides for- wards and downwards during inspiration under the combined influence of the descent of the diaphragm and the forward movement of the ribs and sternum ' (Sibson). In so doing it stretches the pulmonary artery, the ascending arch of the aorta, and the great vessels coming off from the arch ; but it must be remembered that the pericardium is reflected on to the great vessels at the base, being thence continuous with the cervical fascia. Hence, the downward movement of the diaphragm tugs upon these vessels, and is limited by their fascial attachments. CHAPTER XIII. INFLUENCE OF THE RESPIRATORY MOVEMENTS ON THE CIRCULATION OF THE BLOOD. Befoiie considering how the circulation is modified by the respiratory movements, it is necessary to refer briefly to the influences of external pressure on the heart and bloodvessels. The susceptibility of the bloodvessels to outside pressure depends essentially, I conceive, upon the blood pressure within them, and in only a small degree — not mainly, as Michael Foster makes it appear — upon the thickness of their walls : for were the pressure in a blood-capillary as great as that in the aorta, the compressibility of each would be practically the same. As it is, the arteries are comparatively incompressible, their walls being supported by a substantial internal blood pressure, while the veins are much more compressible, owing to the lowness of the pressure within them. "We must think of the arteries as comparatively rigid rods, and of the veins as flaccid, and partly or completely collapsed. It follows that the venous circulation is much more susceptible than the arterial to variations in extravascular pressure. A good instance of the differing compressibility of the arteries and the veins is afforded by (1) the intra- abdominal vessels, (2) the intra-thoracic vessels. 1. De Jager points out that even strong pressure upon the abdomen has very little effect upon the abdominal 6 82 RESPIRATORY EXERCISES arteries, while it serves to express a large quantity of blood from the splanchnic veins.* That the abdominal veins are very susceptible to pressure is well shown by the numerous experiments of Leonard Hill with reference to the influence of gravitation on the circulation. Thus, he has shown that whenever from failure in certain compensatory mechanisms blood gravitates into the splanchnic veins and the right heart is thereby bereft of its supply, simple pressure upon the abdomen suffices to squeeze the blood out of these veins into the right heart and so to re-establish the circulation. 2. Slight modifications in extravascular pressure are sufficient to affect appreciably the calibre of the cavas and the pulmonary veins, especially of the former, in which the pressure is frequently negative, while considerable modifica- tions of extravascular pressure are needed to modify the calibre of the aorta to an appreciable extent ; the pulmonary artery, being much less tense, is more susceptible than the aorta, but much less so than the large intra- thoracic veins. Unlike the bloodvessels, the susceptibility of the heart to external pressure depends not only on the intracardiac blood pressure, but also very largely upon the thickness of the cardiac walls. Thus, the right auricle is easily influenced by external changes in pressure, having both a low internal blood pressure and thin walls. On the other hand, the massive thick walls of the left ventricle render it com- paratively independent of external pressure, especially during systole, when the internal pressure is very high. Modifications of external pressure affect the heart chiefly by favouring or retarding diastole. We now turn to the respiratory movements in connection with these facts. The respiratory movements influence the blood-circulation in a threefold manner : (1) By modifying * Journal of rinjsiologi/, vol. vii., p. 202. INFLUENCE ON THE CIRCULATION OF THE BLOOD 83 the capacity of the intra-pulmonary portion of the pulmonary circuit ; (2) by modifying the pressure upon the heart and such of the intra-thoracic bloodvessels as are outside the lungs, namely, the aorta and its branches, the pulmonary artery and its extra-pulmonary branches, the innominate veins and their branches, the venae cavfe, the azygos veins, and the pulmonary veins ; (3) by modifying the intra- abdominal pressure. 1. With every mspiration the vessels of the lungs expand, contracting again during expiration,* the degree of vascular expansion and contraction being, under ordinary circumstances, in direct proportion to the degree of inspira- tion and expiration. That the intra-pulmonary vessels should open up when the lungs expand and shrmk again when they contract, seems natural enough, but the exact reasons for these alterations in calibre are not so easy to determine. During inspiration the pressure in the alveoli falls, and that in the pleurae, already negative, falls still further, so that the effect of inspiration on the lungs is much the same as that which would be produced by placing them in the reservoir of an air-pump and then exhausting the air, having previously ligatured the pulmonary artery and vems. We know that under these circumstances the intra-pulmonary vessels would dilate, and, indeed, the inspiratory increase in the vascular capacity of the lungs has been attributed to a species of dry cupping.f It must not, however, be supposed that this increase is due solely to diminution of the atmo- * It has been experiiuentally sho\vii that the pulmonary vessels are more capacious after inspiration than after expiration (see McKendrick's ' Physiology,' vol. ii., p. 290). ' If,' writes P. M. Chapman, ' at the termination of expiration the quantity of blood in the lungs is from i'.>" to iV" of the total (Quantity of blood in the bod}-, at the termination of inspiration it will be from ,V to i'...' — Lancet, 1894, vol. i., p. 587. t See Michael Foster's ' Textbook of Physiology,' sixth edition. Part II., p. 650. 6—2 84 RESPIRATORY EXERCISES spheric pressure upon the bloodvessels. Such a dimmution can only directly affect the alveolar vessels, while the inspiratory expansion of the intra -pulmonary vessels in- volves the whole of them. This it does, I imagine, by a diminution in the circumvascular tissue pressure. As inspiration proceeds, the fibres — elastic and others — sur- rounding the vessels become stretched, and thus exert traction upon and expand them. During a complete expiration this circumvascular negative tissue pressure becomes converted into a positive pressure, when the vessels are actually compressed by the surrounding tissues. These two pressures, namely, the intra-alveolar atmo- spheric pressure and the circumvascular tissue pressure, may be made to vary within wide limits. When a forced inspiration is taken with closed glottis, they both fall ; hence the intra-pulmonary vessels suffer a considerable expansion, and blood is sucked in large quantities into the lungs. When, on the other hand, a forced expiration is made with closed glottis, each pressure increases ; hence, the mtra-pulmonary vessels are strongly compressed, and the blood is thus driven out of the lungs. Were variations in the intra-pulmonary atmospheric pressure the sole cause of the variations in the calibre of the intra-pulmonary vessels, it would follow that the lungs could Ije made to contain more blood when con- tracted in full expiration than when expanded in complete inspiration : all that would be necessary would be to inspire forciljly with closed glottis in the former case, and similarly to expire in the latter ; the contracted lung would then contain the maximum supply of blood, and the expanded lung the minimum.* * Seeing that the inspiratory muscles can act to greatest advantage at full inspiration, the lungs, on the above assumption, should contain less blood if a forcible expiration with closed glottis be made at the end INFLUENCE ON THE CIRCULATION OF THE BLOOD 85 But such is not actually the case, for though the mtra- pulmonary pressure may be diminished in the contracted lungs, the circumvascular tissue pressure is necessarily increased. On the other hand, while the intra-pulmonary pressure may be greatly increased in the expanded lungs, the circumvascular tissue pressure is necessarily greatly diminished. It should be mentioned, in this connection, that the breath can be held twice as long when the lungs are expanded in full inspiration as when contracted in full expiration, and this, no matter how we modify the intra- pulmonary atmospheric pressure. No doubt this difference is largely, possibly solely, due to the larger quantity of intra-pulmonary air in the one case than in the other ; but it at least suggests that it may also be partly due to the fact that the circumvascular tissue pressure is negative in the one case and positive in the other, the former favour- ing and the latter retarding the pulmonary flow. In comparing the time during which the breath can be held when the lungs are fully expanded by inspiration with the time during which it can be held when they are fully contracted by expiration, it is well first to induce apnoea by breathing rapidly and deeply for, say, fifteen seconds. I find that if I then hold my breath in full expiration, nearly a minute elapses before dyspncea becomes urgent ; and, curiously enough, the period remains much the same whether, while thus holding the breath, I forcibly inspire, or expire with closed glottis, or do neither. On the other hand, if, after similarly inducing apncea, I hold my breath in full inspiration, I can go two and a quarter minutes of a full inspiration than at the end of a full expiration. Contrari- wise, the expiratory position being the most favourable for the action of the inspiratory muscles, the lungs should contain more blood if a forcible inspiration be made at the end of complete expiration than at the end of complete inspiration. 86 RESPIRATORY EXERCISES before there is an urgent desire to breathe. And here again, the pressure to which the intra-pulmonary vessels are subjected by forcibly inspiring, or expiring with closed glottis, makes no appreciable difference in the time during which the breath can be held. The effect of the inspiratory expansion of the intra-pul- monary vessels is to lessen the resistance which they oppose to the blood-flow, and consequently to increase the rate of flow through the pulmonary circuit, thereby increasing the output from the right heart and the out-flow from the lungs. As against the increased rate of flow thus resulting we must set the diminution in its rate brought about by the widening of the pulmonary bed,^ and a further circum- stance has to be considered in this connection : not only does an increase in vascular calibre tend, by the widening of the bed, to diminish the rate of flow, but the very jJrocess of vascular dilatatioi itself tends in the same direction: for as the vessels open out, the extra vascular space thus created has to be filled with blood, and this process of filling detracts from the forward movement of the blood. By so much as the vessels open out and, as it were, su-allow uj) the blood, by so much is the pulmonary output diminished; and it is conceivable that the vascular dilatation might be so rapid as temporarily to check the pulmonary outflow altogether — nay, actually to suck blood from the left heart into the lungs. How markedly this swallowing-up process detracts from the forward flow may be shown by taking a * Tlie influence of pulmonary expansion on the pulmonary ' bed ' will be most marked where the bed is widest, i.e., in the neighbourhood of the arterioles, capillaries, and venules, and consequently its effect on rate of flow will also be most marked here. The widening of the bed in this region must operate very decidedly in the direction of diminishing the rate of flow, and it should be noticed that an actual diminution in the rate of flow here is compatible witli an increased pulmonary output. TNFLUKNCK OX TUB CIRCL-LATIOX OF THE BLOOD 87 very rapid and deep inspiration after a forced expiration with closed glottis, when the sudden change in the calibre of the pulmonary vessels from the minimum to the maximum diminishes the pulmonary output to such an extent as to cause the individual to grow pale and faint, and even destroy all trace of the radial pulse. This is especially the case in those with low tension. The exact converse of this occurs during effort, as in coughing or lifting a heavy weight. A deep inspiration is first taken, and then a powerful expira- tion with partly or completely closed glottis. In this way the calibre of the pulmonary vessels is suddenly changed from a minimum to a maximum, and as a result the pul- monary blood tends to be driven in both directions, i.e., backwards towards the right heart, and forwards into the left heart. It is not able to regurgitate into the right heart owing to the pulmonary valves, but although checked in this direction, it is doubtful whether much can escape from the right heart during a violent effort. On the other hand, the way into the left heart being open, a large quantity of blood is expressed into it. In this connection it must be borne in mind that the venous portion of the pulmonary circuit is much more compressible than the arterial portion, owing to its comparatively low tension. The effect, there- fore, of a sudden effort is to squeeze a large quantity of blood into the left heart, and thus to increase the aortic input.* It is in this way we can explain a phenomenon I have frequently observed, viz., a swelling up of the systemic arteries — the temporals, for instance — during cough. Even more effective in this respect is a sudden effort with com- * It is true that the extra-puhuonary portion of the puhiionary veins and the left auricle are subject to great pressure during effort, and this must operate in the direction of diminishing the input into the left ventricle ; but it must be remembered that the blood pressure in all of them must also rise very considerably, and that this heightened pressure \vill diminish their compressibility. 88 RESPIRATORY EXERCISES pletely closed glottis. It is probably for this reason that straining at stool and similar efforts are so liable to cause rupture of arterial aneurysms, whether of the small miliary aneurysms of the cerebral vessels or of the large aneurysms situated on the great bloodvessels. Another factor tending to send up arterial blood pressure in these cases is the powerful contraction of the abdominal muscles, and the consequent compression of the abdominal vessels. As I elsewhere point out, compression of the belly may in- crease the work of the heart 30 per cent, by squeezing blood from the splanchnic area into other parts of the vascular system. During effort such compression is probably not able materially to increase the input into the right heart owing to the increase of intra-thoracic pressure, but it tends, nevertheless, to send up the systemic arterial pressure by increasing the peripheral resistance in the splanchnic area. Michael Foster* writes as though the swallowing-up pro- cess above referred to takes place during the beginning of inspiration only, but it is manifest that it must last during its entire period. It is quite possible, however, that it is greatest at the beginning of inspiration, and that in this way it may cause a delay in the increased output brought about by the diminished pulmonary resistance. It will be observed that, while it tends to diminish the pulmonary output, it increases the input by actually sucking blood out of the right heart. 2. In order to understand the influence of the second factor, the facts enunciated in Chapter I. must be borne in mind. It is there pointed out that the heart and its great bloodvessels are, under ordinary circumstances, subjected to pulmonary suction, this suction operating even at the end of an ordinary expiration, and increasing with every inspiration. It constitutes an important aid to the circula- tion, sucking, as it does, l^lood from the veins of the neck * ' Text-Book of Physiology,' sixth edition, Part 11., p. 650. INFLUENCE ON THE CIRCULATION OF THE BLOOD 89 and upper extremities (on which the pressure is at least equal to the ordinary atmospheric pressure) into the innominates and superior cava, and from the abdominal veins (on which the pressure is likewise positive) into the inferior cava ; also from the lungs into the pulmonary veins. Its influence on the heart also favours the circula- tion, inasmuch as it facilitates diastole (the degree of which largely determines the amount of blood Howing into the heart) much more than it retards systole. Ventricular systole must, indeed, be very little influenced by it. The effects just considered are greatly increased when inspiration is made with closed glottis, by which means suction may be raised to — 100 mm. Hg. Under these cir- cumstances the blood is sucked with considerable force into the cavffi and right heart, and from the pulmonary veins into the left heart. On the other hand, such powerful suc- tion must hamper systole, especially auricular systole ; but any retardation of the circulation thus resulting is over- balanced by the acceleration of diastole. Pulmonary suction ceases with a full expiration, the pressure on the heart and great bloodvessels then becoming positive, and if a violent expiration is made with closed glottis, it may amount to 100 mm. Hg or more. Such a pressure on the cavfB and pulmonary veins must tend to obliterate them, and to render cardiac diastole (notably of the auricles) very difficult. The heart and great bloodvessels may, indeed, be so firmly compressed in this way as almost to check the circulation altogether for a time. Since pulmonary suction constitutes an important aid to the circulation, it follows that any loss of pulmonary elasticity is detrimental to the same. This is one of the reasons why in emphysema the blood tends to accumulate in the systemic veins. 3. With every descent of the diaphragm the intra- 90 RESPIRATORY EXERCISES abdominal vessels are compressed. The tense arteries are very little influenced by this pressure, but the flaccid veins yield to it, blood being squeezed out of them into the right heart, for though the intra-abdominal veins are not pro- vided with valves, those of the lower extremities have them, and consequently the blood cannot regurgitate from the iliacs into them. Hence, as Marey observes, the pressures in the intra-thoracic and intra-abdominal veins run in opposite directions, the former falling during inspiration, and the latter rising, and vice versa. (I refer to diaphrag- matic inspiration.) In the portal veins the pressure may rise several millimetres of mercury.* The effect of diaphragmatic inspiration in increasing intra-abdominal tension and thus squeezing blood out of the intra-abdominal veins into the right heart, is largely dependent upon the condition of the anterior abdominal walls. When these are lax and flaccid, tension is very little increased, even by extreme contraction of the diaphragm. On the other hand, when the abdominal walls are strongly contracted or firmly compressed, as by a belt, or by flexing the body on the thighs, forcible contraction of the diaphragm may cause considerable augmentation of tension. It should be observed, however, that inspiration does not always augment intra-abdominal tension ; it may produce the very opposite result. Thus, when the fullest possible thoracic breath is taken, abdominal tension falls, owing to the powerful suction of the lungs upon the diaphragm ; and the fall l)ecomes still greater if the breath be taken with closed glottis. The effect of this diminished tension is to draw the blood from the lower extremities and abdomino- pelvic viscera into the intra-abdominal veins. t * Marey points out that the action of the abdominal muscles, which (in the dog, at least) tend to contract during expiration, and thus to compress the intra-abdominal veins, introduces a disturbing influence (' La Circulation du Sang,' Paris, IBBl, pp. 417, 529), t For a practical application of the above facts, see p. 151 ct scq. INFLUENCE ON THE CIRCULATION OF THE BLOOD 91 While intra-abdominal pressure tends to fall during ordinary expiration, it increases when expiration is forced, especially when the glottis is closed, as in effort ; but the compression of the intra-abdominal veins thus resulting does not urge the blood onward, owing to the concomitant increase in intra-thoraeic pressure. It will probably be concluded from the foregoing obser- vations that the ordinary respiratory movements favour the circulation, but it is doubtful whether in ordinary breathing they have any decided effect. While the rhythmic descent of the diaphragm aids the circulation, it is doubtful whether the rhythmic expansion and contraction of the lungs have the same result, seeing that the accelerating influence of expansion is neutralized by the retarding influence of contraction. We have seen that pulmonary suction is largely dependent upon the degree to which the very elastic lungs are stretched. During inspiration the elastic tension rises to a given point, and during ex- piration it falls again to the original point. Hence the mean tension is the same during both inspiration and ex- piration, and so far as pulmonary suction is dependent upon pulmonary tension, it is the same during both inspira- tion and expiration. Pulmonary suction is, however, also influenced by the intra-pulmonary air pressure. This latter falls during inspiration, and in so doing increases the suc- tion upon the heart and extra-pulmonary bloodvessels, while it also causes an expansion of the intra-pulmonary vessels ; but the accelerating influence of this diminished intra-pulmonary pressure is counteracted by the expiratory increase of intra-pulmonary pressure, which not only diminishes the suction upon the heart and great blood- vessels, but likewise the calibre of the intra-pulmonary vessels. 92 RESPIRATORY tXERCISES It would thus appear that if msph-ation and expiration are of equal duration (as under ordinary circumstances they practically are), the respiratory expansion and contraction of the lungs will not aid the circulation. How, then, are we to account for the fact that the circulation is impeded when the breath is held? Marey has shown, by taking tracings of the right ventricle under these conditions, that its beats become slower and that it manifests an increasing difficulty in emptying itself, the amount of residual blood increasing with every beat. This latter fact is further attested by the increase of dulness to the right of the sternum, and by the distension of the veins of the head and neck. These phenomena certainly suggest that by holding the breath we remove a something which facilitates pul- monary circulation. It must, however, be remembered that when an individual is asked to hold his breath, he closes the glottis, and makes an unconscious expiratory effort, thus increasing the intra-pulmonary pressure ; also that holding the breath checks the respiratory blood-change, the pulmonary circulation being hindered in consequence.* But while the rhythmic movements of the lungs do not under ordinary circumstances aid the circulation, there are certain positions of the chest and certain modes of breathing which are favourable to it, and it behoves us thoroughly to understand what these are. Since pulmonary suction aids the blood-flow, it follows that increase, in mean puhnonary suction Kill favour the circulation. Such an increase may be effected by inflating the chest to the utmost with every inspiration, and limiting the expiratory range. In this way the transference of blood from the veins to the arteries is facilitated. It may further be aided hy ijrolowjiiKj the inspiratory periods and shortening the expiratory, for by this means the period of lessened becomes longer than the period * See pp. 142-144. INFLUENCE OX THE CIRCULATION OF THE BLOOD 93 of heightened intra-iDulmonary tension ; i.e., the period of acceleration becomes longer than that of retardation. The mode of breathing, therefore, most favourable to the circulation is to take slow full inspirations (preferably through the nose}, followed by short and somewhat shallow expirations (preferably through the mouth). This is, indeed, the method often instinctively resorted to when there is need of facilitating the transit of blood from the cavfe to the aorta. In running, for instance, the blood is diverted in large quantities from the splanchnic area to the muscles, whence it is pumped with great rapidity into the right heart, which has some difficulty in disburdening itself of this large access of blood. Now, the mean size of the chest is manifestly increased in running, full inspirations being taken, while expirations stop short of their ordinary limit. Further, as breathlessness becomes marked the expirations get distinctly shorter than the inspirations. A ready way of demonstrating this disproportion is to notice how many paces can be taken during the one and the other respectively. Legrange found that when breathlessness became decided he took thirteen paces during each inspiration, and only five during an expiration. When the breathlessness has become pronounced it will be found quite impossible to make the two acts equal : inspiration may be voluntarily prolonged, but not expiration, which is always cut suddenly short by the imperious demand to inspire. Hence it is that expira- tion does not proceed to the ordinary limit, the mean size of the chest being in consequence increased and the circula- tion through the lungs thereby facilitated. Legrange, who was, I believe, the first to point out the alteration in rhythm just referred to, explains it, as I have done, by reference to the favouring influence on the circula- tion of deep inspirations, and the retarding influence of deep expirations, the individual in consequence instinctively 94 RESPIRATORY EXERCISES prolonging the one and shortening the other. The altered rhythm cannot, he argues, be due to mechanical causes, seeing that it occurs in exercises of the arms as well as of the legs, and that it lasts for some time after the exercise "which has induced it. In all forms of dyspnoea there is the same difficulty in getting the blood through the lungs and the same tendency to take full inspirations and short incomplete expirations. Hence, in dyspncea we find the inspiratory muscles more active than the expiratory. Influence of the Respiratory Movements on Arterial and Venous Tension. — We are now in a position to consider this influence.* Inspiration favours the flow of blood into the cavae and right heart, from the latter into the lungs, and from the lungs into the left heart. In short, it favours the trans- ference of blood from the systemic veins into the systemic arteries, and its effect is most marked when the glottis is closed. Hence, inspiration causes a fall of venous blood pressure, especially in the superior cava (the cranial fontanelles and veins of the neck collapsing), -f- and a rise of pressure in the systemic arteries. | Expiration, on the other hand, impedes the flow of blood from the veins into •*• The influence of the respiratory movements on arterial tension has been skilfully treated of by De Jager. See Jour. Pliys., vol. vii., No. 2, p. 130; also Pltiger's Archiv., ]3cl. 20, 27, 33, and 36, and Arch. Neerl. T., 19 and 20, which contain copious references to the literature of the subject. j" The effect of inspiration upon the pressure in the inferior cava varies according to circumstances : a deep abdominal breath increases it ; a deep costal breath diminishes it. X Inspiration, by increasing the amount of blood in the lungs, tends to cause a fall in arterial as well as in venous pressure ; but by diminish- ing ])ulmonary resistance it tends to cause a rise in arterial pressure, the latter effect preponderating. See De Jager, Jour. P/iys., vol. vii., No. 2, pp. 196-198, 206-208. INFLUENCE ON THE CIRCULATION OF THE BLOOD 95 the arteries, its effect being greatest when forced and with closed glottis. Hence, venous blood pressure rises during expiration, the fontanelles and cervical veins swelling up, while arterial blood pressure falls. These respiratory alternations in arterial blood pressure do not exactly synchronize with the respiratory movements. Thus, the expiratory fall continues into the beginning of inspiration, possibly because the first effect of inspiration is to diminish the pulmonary output ; indeed, this inspiratory fall may, as we have seen, be very marked if a deep and rapid inspiration be taken after a forced expiration with closed glottis. On the other hand, the inspiratory rise continues into the beginning of expiration, the first effect of which is to augment the pulmonary output by expressing blood into the left heart. If expiration be made powerfully with partly or completely closed glottis, this expiratory rise may, as already observed, be decided. It is, however, only momentary, the final effect of a protracted expiration of this kind being a considerable lowering of arterial and a corresponding rise of venous pressure, for not only is the circulation through the lungs and great veins entering the heart impeded, but the action of the heart itself. Eduard Weber pointed out that even a moderate expiratory effort, while the mouth and nostrils are closed, renders the pulse slow and small and the heart-sounds indistinct, more forcible expiration causing the radial pulse to disappear completely, an efl'ect which Oertel attributes to the ' com- pression of the subclavian artery by the strongly raised upper ribs.'* "Whatever augments intra-thoracic pressure, such as cough- mg, vomiting, straining at stool, lifting a heavy weight with closed glottis, has similar effects. These different kmds of * Von Zeimssen's 'Handbook of General Therapeutics,' vol. iii., p. 468. 96 EESPIRATORY EXERCISES effort and their influence on the circulation are more par- ticularly considered in Chapter XVI. It has been shown by Leonard Hill and Barnard that external compression of the thorax affects the circulation in the same way as expiration with closed glottis, and they insist that whatever raises intra-pulmonary air pressure causes a fall in arterial and a rise in venous pressure, ' the diastolic filling of the heart and the passage of blood through the lungs being thereby impeded,' so that the effect on the circulation is the same as that produced b}^ obstructive lung disease and cardiac failure. Tight-lacing causes external compression of the thorax, and therefore impedes the pulmonary circulation, damming it back upon the systemic veins. These two physiologists have also brought out a point in connection with the radial pulse which has hitherto been strangely overlooked, namely, that the radial artery has two venae comites, and that the quality of the radial pulse is affected by the degree to which these two veins are dis- tended. When examining the radial pulse, we feel in fact three vessels, and these we may speak of as the radial band. Now, Blake observed that forced expiration increased the size of the radial pulse. This was proved by careful obser- vations with the arteriometer, and by the fact that the base line of the sphygmographic curve rises with forced expira- tion. How to reconcile this fact with the fact that increased intra-thoracic pressure lowers arterial tension was a problem which Blake presented to Leonard Hill for solution. By a series of ingenious experiments Hill and Barnard have conclusively proved that the increase in the size of the radial pulse produced by forced expiration is due to disten- sion of the \enni comites,* and that anything which causes * Such an expiration may, as we have seen, produce a distension of the arteries, but this is momentary only. INFLUENCE ON THE CIRCULATION OF THE BLOOD 1)7 the blood to be damiiied back upon the great veins pro- duces the same effect. They msist that it is impossible to differentiate between the venous and arterial aspects of the radial pulse, and that the fulness of the venT}. Cohnhcim attributes emphysema in a large number of cases to a congenital defect of the pulmonary elastic tissue (' Principles, etc., of Medicuae,' 3rd edit., vol. i., p. 967, C. H. Fagge). Sir Richard Douglas-Powell also alludes to the loss of pulmonary elasticity as a factor in the pathology of hypertrophous emphysema, though I am not able to accept all his deductions. He argues thus : the elasticity of the lungs is greatly diminished, and may be lost in this disease, and pulmonarj- suction thus being inadequate, the chest- walls are no longer sucked in and bent beyond the neutral point at the end of an ordinary expiration ; wherefore the thorax will have the same circumference at the beginning of inspiration as normally it has at the end thereof [it is not explained why the chest expands consider- ably beyond this point in emphysema] , and inspiration is no longer aided by the passive recoil of the ribs, which have in consequence to be lifted with every inspiration (' Diseases of the Lungs,' 4th edit., chap. X.). This explanation does not appear to me to be satisfactory, for I do not see how inspiratory recoil aids inspiration, since it is neutralized by pulmonary suction, upon which, indeed, it depends. Suppose the latter to be represented by six, the inspiratory recoil of the ribs operating in the opposite direction will be represented by the same numeral, and the resultant, as far as inspiratory movement is concerned, is nil. Disappearance of pulmonary suction impUes the disappearance of inspiratory recoil, but such disappearance will make no difference in the amount of inspiratory force needful. The need for increased inspiratory force, referred to by Douglas-Powell, is, I believe, due to that expansion of the chest which is a feature of the disease ; for the more the chest is enlarged, the more difficult does it become to enlarge it further. Jenner develops Budd's idea, and refers to the (possible) influence of duuinished costal elasticity in the pathology of hypertrophous emphy- sema, contending that this interferes with proper costal recoil during expiration, which therefore is imperfectly performed. VI 178 RESPIRATORY EXERCISES the so-called ' atrophous ' variety — because it does not come on until the chest has acquired the iSixity peculiar to old age ; but when the disorder begins in early or middle life, ■while the thorax is still mobile, considerable thoracic expansion may occur. Similarly, expansion tends to be more pronounced the more muscular the individual. It is therefore apt to be small in those with feeble muscles. Hence an additional reason why the chest should not expand in senile emphysema. On the other hand, those of powerful muscular build are apt to get very large chests if they develop emphysema, and it is not therefore surprising that the most pronounced cases of large-lunged emphysema are generally met with in those following laborious occupa- tions. The expansion of the chest is usually most marked in its upper part. This may be explained by the effect during cough of the sudden contraction of the abdominal muscles and uplifting of the diaphragm in driving the air from the lower regions of the lungs into their apical portions, which thus tend to thrust the upper part of the chest outwards. The powerful contraction of the abdominal muscles that then takes place leads to an actual contraction Wilson Fox, who gives the most masterly account of emphysema that I have met with, supports Budd and Jenner, aiid supplies, as I think, a most important link in the chain of argument, viz., the tendency of dyspnoea to excite the inspiratory muscles more than the expiratory. He observes that the emphysematous chest, ' especially vmder exertion, is expanded to its fullest limits by the muscles of in- spiration, while the subsequent retraction necessary for the proper performance of respiration is hindered by the want of elasticity in these structures. As a consequence, a potential dyspnoea is produced, the immediate reflex effect of which is to create a tendency to further deep inspirations, and the inspiratory muscles become as a consequence hypertrophied.' (Op. cit., p. 158.) Neither Budd, Jenner, nor Wilson Fox, however, explain satisfac- torily why the chest is kept jyermanently expanded and fixed. RESPIRATORY EXERCISES IN EMPHYSEMA 179 of the lower chest, which therefore cannot be distended during the cough ; but the upper chest, not being so imme- diately under the control of the expiratory muscles, may sufier temporary expansion, and this frequent repetition may render permanent. It is on these lines that Jenner and Mendelssohn explain the frequent occurrence of emphysema at the apices. I have laid stress upon the mechanism of thoracic expan- sion in hypertrophic emphysema because the process is largely an injurious one, and should, as such, be combated. It is harmful because it leads to excessive stretching of lung tissue, and this, as Budd insists, is alone sufficient to induce emphysema. Let us suppose healthy lungs to lose their elasticity, and the chest to assume m consequence the posi- tion of super-extraordinary inspiration. The continuous stretching of the alveoli thus induced will not only diminish pulmonary elasticity still further, but will so interfere with alveolar nutrition (which is dependent upon the ample rhythmic relaxation of the alveoli) as to give rise to so- called compensatory emphysema. It would appear there- fore that mere loss of pulmonary elasticity is, by inducing thoracic expansion, sufficient of itself to bring about em- physema. The loss of pulmonary elasticity in emphysema has a further injurious effect in that by diminishing pulmonary suction it interferes with an important accessory force of the circulation. The progressive enlargement of the chest in emphysema tends to produce another evil — its fixation, and thus to diminish the expiratory range. In extreme cases the bony thorax may indeed be bereft of respiratory power, being either immobile, or admitting only movement as a whole without any alteration of capacity. Eespiration is then practically confined to the diaphragm, which, however, does 12—2 180 RESPIRATORY EXERCISES not move with its normal freedom on account of its flat- ness, due to the expansion of the lower chest and the diminished suction on its upper surface. It has, in fact, been said that in some extreme cases it is altogether incapable of enlarging the thorax, its contraction causing, on the con- trary, an actual drawing-in of the ribs.* I have not, how- ever, met with a case of emphysema in which the diaphragm had entirely lost its inspiratory power, and it is certain that in most cases a fair quantity of air can be inspired by its means, expiration being chiefly effected by a forcible con- traction of the expiratory muscles, whereby the diaphragm is thrust upwards. If in cases of this kind the hand be placed upon the belly, it will be felt to obtrude during diaphragmatic descent, and to become hard during expira- tion from contraction of the abdominal muscles. The immobility of the thorax is one of the worst aspects of emphysema, and has not received the attention it deserves. The diminution in respiratory area is serious enough, but this would be largely compensated for if only the patient could expire adequately. The breathlessness is due far more to the meagreness of the tidal current than to the limitation of the respiratory surface, and be it noted, as Walshe long ago pointed out, the emphysematous patient does not make up for deficient depth in breathing by increased rate. That the diminished expiratory range in emphysema is due to the fixity of the thorax I have no doubt. I can find no other adequate cause. It is frequently attributed to loss * Thus Wilson Fox writes : ' The contraction of the diaphragm may in some cases even appear to retract the lower ribs, acting as it some- times does from a lower level, which in expiration may even be below that of the ribs The epigastrium may thus sink during inspiration and bulge during expiration, owing to the slowness with which the air escapes, wliile the chest is compressed by the accessory muscles of expiration.' Oj). cit., p. 171. RESPIRATORY EXERCISES IN EMPHYSEMA 181 of pulmonary elasticity* ; but though such loss prevents ordinary expiration from taking place by simple elastic recoil, as happens under normal conditions, it cannot account for the inability of the patient to expire freely by means of the most powerful expiratory effort. Nor can the limited expiratory range be attributed to impediment in the air-passages. It has been argued, for instance, that the loss of pulmonary elasticity in emphysema * interferes with that condition of permanent patency in which the small bronchi are normally held by the constant traction upon them of the elastic lung from all sides. In emphysema this traction becomes, in expiration at first, entirely neutra- Hzed, and in marked cases collapse of the bronchioles must occur during expiration. 'f It seems, however, doubtful whether this loss of pulmonary elasticity leads in any marked degree to such collapse, seeing that in this disease the alveolar walls are considerably stretched. Be this as it may, it is certain that any obstruction thus arising is in- sufficient to account for the limited expiratory range, seeing that air can be expressed from the lungs by the thrusting upward of the diaphragm as the result of the contraction of the abdominal muscles. In extreme cases the breathing may be almost wholly abdominal, and this indicates that fixation of the chondro-osseous thorax is the cause of the diminished range. Treatment of Emphysema.— From the foregoing observa- tions it is manifest that in the treatment of emphysema we should seek (a) To preserve the elasticity of the lungs and cartilages; (b) by preventing overaction of the costal elevators to check thoracic expansion ; (c) to maintain the normal mobility of the thorax. (a) I have already dealt with the means of preserving * See Wilson Fox, o^. cit., p. 171. t Sir Richard Douglas-Powell, o^). cit., pp. 194, 195. 182 RESPIRATORY EXERCISES pulmonary elasticity (see p. 7). I would here only insist upon the importance of avoiding strong muscle-efforts* and all exercises calculated to induce great dyspnoea.! (h) In order to prevent overaction of the inspiratory muscles, and thus to check thoracic expansion, the patient must guard against all causes likely to induce dyspnoea, which, as we have seen, excites the inspiratory muscles more than the expiratory. We should further seek to antagonize the former by calling the latter into play. From the earliest phase of the disease recourse should be had to systematic expiratory exercises. Thoracic expansion begins long before the recognised signs of emphysema show them- •selves, and it is in this early phase of the disease that the expiratory exercises should be begun. Unhappily the patient does not often come under the physician's notice for emphysema until the disease has made considerable progress, but it may frequently be observed when he is con- sulted for some other condition. The expiratory exercises I adopt are very simple. They consist in the deepest possible expirations. Starting from * I have now under observation a man, aet. 20, whose chest is very emphysematous and fixed. There is no history of bronchitis, but inquiry eUcits the fact that for the past six years, i.e., since the age of fourteen years, he has been engaged in an occupation which requires him constantly to hft heavy weights. It is no unusual thing for him to have to lift two hundredweight ! In this case there can be Httle doubt that the emphysema is due to loss of pulmonary elasticity resulting from heightened intra-alveolar tension, coupled with exces- sive inspiratory action consequent upon dyspnoea. •f ArValdenburg cites the case of a student who became emphyse- matous in consequence of rapidly mounting several flights of stairs daily. Waldenburg attributed, and I think correctly, the loss of pul- monary elasticity and resulting emphysema in this case to the long- continued over-expansion of the lung resulting from great dyspnoea. He also refers to an interesting case of emphysema similarly induced in a professional lady swimmer who used to remain three minutes under the water. (Waldenburg, ojj. cit, pp. .'50-52.) RESPIRATORY EXERCISES IX EMPHYSEMA 183 the position of ordinary inspiration the patient should expire to the utmost with mouth wide open, the body being bent forward the while, so as to favour compression of the diaphragm from below. These exercises should be practised for at least half an hour twice daily. Special exercises of the abdominal muscles should also be resorted to. Thus the patient, lying supine, is directed to raise his body, the legs being held by an assistant if necessary. In this way the great depressors of the thorax may be considerably developed. Eetraction of the belly, by which the transver- salis is exercised, should be frequently practised, and thus the tendency to undue opening- out of the costal arch pre- vented. Massage and faradisation of the abdominal muscles may in some cases be called for. Apart altogether from the advantage gained in thus antagonizing the costal inspiratory muscles, it is of the greatest advantage to the emphysematous patient to have firm and well - developed abdominal muscles, since a lax state of these predisposes to many evils which tell against him, such as flatulence, costiveness, dislocation of the abdominal viscera, and the accumulation of blood in the portal area. (c) By means of the expiratory exercises just described we may also check the tendency to fixation of the thorax, indeed, we can in this way generally increase thoracic mobility considerably. Defective thoracic mobility in an apparently healthy man is always suggestive of com- mencing emphysema. Here the use of the spirometer comes in. If we find a man of forty with no apparent lung disease to have a chest measurement of 38 inches, and a vital capacity of only 230 cubic inches, we may be pretty sure that he is on the road to emphysema. I would utter a word of caution against the assumption that thoracic girth is a safe measure of pulmonary efficiency. 184 RESPIRATORY EXERCISES Vital capacitj^ is a much more accurate test. The spi- rometer often shows a chest of 34 inches to have a greater vital capacity than one of 38 inches. When the chest is very fixed it may be necessary to resort to special means to promote the expiratory move- ment. In addition to those already described (p. 157), we maj^ cause the patient to expire forcibly into a chamber of rarefied air, so as to reduce the ' residual ' air to a minimum* or he may sit in a chamber of compressed air, and expire into the external atmosphere. The inhalation of condensed air would theoretically appear to be wrong, seeing that it promotes thoracic expansion. As a matter of fact, it may prove of great service when dyspnoea is great, by favouring the oxygena- tion of blood. The patient may sit either in the com- pressed air chamber, or inspire compressed air, in either case expiring into rarefied air. It need scarcely be said that the inhalation of rarefied air is hurtful, and hence emphyse- matous patients should not reside in mountainous districts. The chief drawback to the treatment just sketched out is getting the patient to persevere in it long enough. It involves a considerable sacrifice of time, and is apt to grow irksome. Few good results in this world, however, can be obtained without both pains and patience, and certainly the end gained in this instance is worthy the cost. CHAPTER XXIII. RESPIRATORY EXERCISES IN HEART DISEASE. Kespiratoky exercises are valuable adjuncts in the treatment of heart disease, for they favour the development of the lungs, and thereby diminish their tendency to disease— a tendency it is most important to check, owing to the extra work lung disease casts upon the right heart. The importance of securing the fullest possible development of the lungs in heart disease has been strangely overlooked. The more completely the lungs are developed, the more capacious is the pulmonary vascular system, and the less is the resist- ance which it opposes to the right heart, pulmonary resistance being in inverse ratio to pulmonary capacity. This fact is, indeed, instinctively taken advantage of in heart disease, in which we may frequently observe over- action of the inspiratory muscles and an increase in the mean size of the chest. Not only is the breathing area in this way increased, but the pulmonary vascular capacity also ; and hence the work of the right heart is diminished. Now, all organic cardiac disease, but especially mitral affections and primary disease of the right heart, tend to cast extra work upon the right side ; and it is, therefore, of the utmost importance in all cases of heart disease to secure the maximum development of the lungs. Consider, for instance, what happens in mitral disease. In both ob- struction and leakage at the mitral orifice the pressure in 186 RESPIRATORY EXERCISES the pulmonary circuit is increased, a fact which proves that the resistance which the right heart has to overcome is augmented. This increased pressure obtains throughout the entire pulmonary segment, both in the pulmonary artery itself and in the pulmonary veins as they open into the left auricle. The augmented pressure in the latter is obviously compensatory, tending, as it does, to minimize the evil effect of the valvular disease. Now, the larger the lungs, so much the less will be the extra force demanded of the right heart in order to bring about the necessary in- crease of pressure in the pulmonary veins, and the longer will the right heart be able to hold out. Given two indi- viduals suffering from mitral disease, and identical in all respects save that the one has well-developed and the other ill-developed lungs, the prognosis will be very much better in the former case than in the latter. It follows that in all cases of failing heart every care should be taken to keep the lungs in as perfect a state of efficiency as possible. I have seen many deaths from heart disease which could have been averted had this cardinal fact been acted upon. It is a point which we should always impress upon the patient. As a rule it is upon the lungs rather than upon the heart that his attention should be concentrated. Not only do respiratory exercises do good in heart disease by promoting pulmonary efficiency, but also by aiding the circulation of the l^lood ; for, as we have seen, it is possible so to modify the respirations as materially to facilitate the transference of blood from the veins to the arteries. By their means the lymphatic circulation may also be aided, lymph being pumped from the peritoneal cavity into the pleura;, from the latter and from the pericardium into their respective lymphatics, and from the two thoracic ducts into the great veins. Such aids to the lymph flow are very RESPIRATORY EXERCISKS IN HEART DISEASE 187 helpful in heart disease, especially when there is a tendency to oedema and ascites. Forced abdominal breathing should be employed for removing the latter. I would emphasize the fact that it is not merely in mitral disease that breathing exercises are useful ; they should be resorted to both in aortic valve disease and in weakness of the heart-muscle, seeing that the evil effects in both cases tend to w'ork backwards beyond the mitral ring, and no sooner does this occur than the right heart feels the strain. It is largely through their influence on the respiratory movements that such exercises as walking (especially hill- climbing), running, swimming, rowing, riding, not to mention talking and singing, are useful in heart disease. Even the so-called Nauheim treatment benefits in large measure by causing an increase in the mean size of the chest, and thus favouring the pulmonary circulation.* How profoundly the breathing is affected in hill-climbing is well shown in the following passage from Oertel : ' If the locomotion be extended till the patient ascends elevations or mountains, not only is there a great increase of sweating, but the patient soon breathes only by summoning all the means at his com- mand. He is obliged to stop every ten or tw^elve steps. The frequent and loudly audible respirations begui with long-drawn and deep in- spirations, with spasmodic contraction of the diaphragm, and the patient supports himself against some fixed object, his alpenstock, e.fj., the pectoral muscles labouring hard, and the ribs being raised by tlie intercostals. The expiration, on the other hand, is but short, and is quickly followed by the long-drawn inspu-ation. The same thing occurs every fifteen or twenty steps, without any diminution in the intensity of the respu'atory movements, and the exertion can go on for hours with but slight interruption. But by exercise the respiratory muscles, lilie any other muscles, undergo a gi-eat increase of their functional capacity.' f * For the author's views on the rationale of the Nauheim treatment, see Brit. Med. Jour., vol. ii., p. 712, 1896, and Lancet, 1896, vol. I., p. 951. t Von Ziemssen's ' Handbook of General Therapeutics,' vol. vii., p. 32. 188 RESPIRATORY EXERCISES Oertel here refers to the great shortness of expiration as compared with inspiration. He might have added that the expirations are not only short but incomplete, and that the mean size of the chest is therefore increased. I have already pomted out that this is the mode of breathing best calculated to facilitate the pulmonary flow, and thus to relieve an overburdened right heart. The following passage shows that Oertel himself re- cognised that some good end was served by this altered mode of breathing : ' Through the powerful and involuntary respiration caused by hill- climbing the thorax enlarges in all its dunensions, the lungs attain then* utmost possible resjnratorjj disteiision, and from the enlargement of their vessels are able to receive far greater quantities of blood. The intensity of the respiratory movements, which are conducted with all the strength possible, causes the aspiration of more blood into the thorax . . . the exit of the blood from the right heart is thus facili- tated. . . . ' By these processes m the lungs, part of the hindrances exciting and keeping up the circulatory derangement are removed, and the cu'cula- tion becomes freer. Inasmuch as for a long time after each ascent the thorax has a greater mobility and expands more easilj^, so the alteration in the pulmonar}^ circulation also outlasts the period of the ascent ; and by repetition of these muscular exertions we are enabled to bring about a permanent increase in the capacity of the pulmonary vessels by increase of thoracic mobility, enlargement of the thoracic space, and increase of pulmonary capacity.'* I will not say anything further on the treatment of heart disease in this place, as I propose to deal with the subject at length in a separate work. * Von Ziemssen's ' Handbook of General Therapeutics,' vol. \u.., pp. 165, 166. CHAPTER XXIV. RESPIRATORY EXERCISES IN THE TREATMENT OF NERVOUS DISEASES. Great benefit can be derived from respiratory exercises in functional diseases of the nervous system. This is not surprising when we reflect upon their influence on the circulation of blood and lymph. That they exert a pro- found influence upon the brain is shown by the increased power of sustained voluntary effort which they confer (see p. 141), as also by the giddiness which they not in- frequently induce, especially when first undertaken. By accelerating the flow of blood and lymph in the nervous system, they not only increase the supply of oxygen and food-stuffs, but they also promote the withdrawal of waste- products, and all this, be it noted, while the nervous system remains in a state of comparative rest. Nor must we in this connection neglect the beneficial influence of respiratory exercises on the digestive viscera, notably on the liver. There can be little doubt that auto -intoxication plays a prominent part in the causation of functional nervous disorders, and that such auto-intoxication largely results from faulty action of these viscera ; and I cannot but think that much of the benefit derived from respiratory exercises in nervous disease is wrought through the digestive system. Finally, the influence of suggestion, which plays so pro- minent a part in therapeutics, must not be forgotten. 190 RESPIRATORY EXERCISES But whatever be the mode in which respiratory exercises benefit, in functional nervous disorder their good effect is unmistakable. One rarely fails to get benefit from them in neurasthenia ; and in inordinate blushing this mode of treatment has yielded surprising results. Those who have had no experience of this disease — for such, in truth, it is — can have no conception of the misery it may cause. I have known it to prompt to suicide. In all such extreme cases the sufferer is morbidly self-conscious, and is of nervous temperament, although I have frequently been told by patients "of this kind that if only the tendency to blush were removed all would be well with them, this being, as they thought, the beginning and end of their sufferings. I have, however, met with a number of cases in which morbid self -consciousness and other evidences of the nervous diathesis have persisted after the morbid tendency to blush has been cured. The following is an instance of morbid blushing cured by respiratory exercises : M., set. 28. Until set. 14 lie was devoid of morbid self-consciousness. At this time he one day suddenly and unexpectedly blushed in class. This was made the subject of chaff by his schoolfellows ; thence- forward he became recognised as a blusher, and he was so plagued and tormented that school became unbearable, and he begged his parents to take him away, which they did. Hereafter his entire life was dominated by the dread of blushing, and of being the object of remarks by others. He spent two years with a family in Germany, in order to avoid association with other boys, and after being under a tutor in England entered the University. Here .he was so fearful of being chaft'ed by the men that he kept entirely to himself, making no friends, and eventually finding himself compelled to leave college without graduating. After this his time was mainly spent in travel, so as to avoid close association with others, and in the vain endeavour to flee from his trouble. The fear that he might at any moment blush and be an object of derision was never absent all these j-ears. It formed the background to all his thoughts. He went to sleep with it, it troubled his dreams, he awaked with it. He felt himself debarred THE TREATMENT OF NERVOUS DISEASES 191 from marriage, and, indeed, from all social intercourse ; and, in spite of youth, position, and sound physical health, his life was so utterly miserable that he had serious thoughts of suicide. It was then that I first saw him. It would need more space than I can afford to describe the method of treatment which was adopted with entire success in this case. It was, of course, in large degree psychical, but the result was achieved mainly, I believe, by respiratory exercises. The patient threw himself enthusi- astically into the treatment, and for many months spent an hour every morning and evening in exercises. This gradu- ally lessened the vaso-motor instability. The dread that the tendency to blush would return persisted for some time, but eventually yielded to mental treatment. The subjoined is a case of severe hypochondria in which respiratory exercises did great good : M., set. 30. Has for some 3'ears thrown great energy into his busi- ness. Lives in constant fear of having some deadly malady. If he feels a pain, or unpleasant sensation anywhere, at once fancies it is the precursor of some terrible illness, and even after he has been assured, and apparently convinced of the contrary, will again and again recur to the matter. Thus on one occasion he experienced numbness in the feet, and it was with the greatest difficulty he could be persuaded that it was not locomotor ataxy ; and, on another occasion, an urticarial rash made him fancy he was going to get typhoid. This patient rapidly improved under a course of respira- tory exercises, and though he is still inclined to exaggerate the importance of trivial symptoms, he is practically cured. Note. — As showing how profoundly breathmg exercises affect the nervous system, I may mention that a patient now under treatment informs me that his susceptibility to alcohol is very decidedly diminished by taking a series of deep breaths. CHAPTEE XXV. RESPIRATORY EXERCISES IN THE TREATMENT OF DIGESTIVE DISORDERS. DisoEDERS of digestion may often be greatly benefited by breathing exercises, which are capable of profoundly influ- encing the circulation of lymph and blood m the digestive viscera. It must be remembered that general muscle- exercises, such as walking, runnmg, cycling, are incapable of producing such a localized effect, for in their case the effect upon the circulation is widespread, the splanchnic circulation being often depressed, rather than stimulated, owing to the determination of a large mass of blood to the musculo-cutaneous system. Hence it is that active muscle- exercise after a meal tends to retard, rather than to pro- mote, digestion. But by suitable and specially-adapted breathing exercises we are able to determine a large flow of blood to the splanchnic area, and at the same time to quicken the flow through it, and we are also able to accelerate the flow of chyle. As a result, the nutrition of the liver and alimentary tube is stimulated. The latter acquires increased tone, and is thus enabled to contract more effectively upon its contents, while the secretion of the digestive juices and the absorption of the food-stuffs are promoted. Most forms of dyspepsia, gastric and intestinal, benefit by suitable breathing exercises, but perhaps the atonic forms chiefly. Intestinal dyspepsia has not yet received the atten- THE TREATMENT OF DIGESTIVE DISORDERS 193 tion it merits. Many a one who does not suffer from any of the obtrusive symptoms of gastric dyspepsia, such as pain, flatulence, weight, and acidity, and who would stoutly deny the charge of being dyspeptic, is a martyr to intestinal dyspepsia and to the many forms of blood-poisoning which it entails. In cases of this kind we shall often find breath- ing exercises a most valuable adjunct to other treatment. ' As regards the movements of the stomach proper,' writes Allchin,* 'there is reason to believe that they are capable of being aided in their effect upon the gastric con- tents by the movements of the diaphragm and even of the heart, which may together be sufficiently effective to com- pensate for the complete absence of the stomach peristalsis when that organ, by adhesions or other causes, is incapable of acting.' If such is the case, how much more likely are we to act mechanically upon the stomach (and intestines) by special exercises of the diaphragm and anterior abdominal muscles ! How potently these act is well shown by their power to dislodge flatus. This in itself is no small gain, seeing how distressing are the symptoms resulting from its mere mechanical presence. ■ These exercises will be found of great benefit in treating constipation. Quite recently a patient to whom I had recom- mended them for quite another cause wrote, saying that he intended to persevere in them if only because they enabled him to have a daily evacuation. In selecting the exercises for dyspepsia, we should choose those which have the most effect upon the abdominal circulation. One of the most valuable is alternate con- traction of the diaphragm (while firm pressure is made on the al)domen) and retraction of the belly. The exercises for strengthening the abdominal muscles (especially when the latter are flabby) will also be found of the greatest service. * Lancet, 1897, vol. ii., p. 1031. IS CHAPTEE XXVI. RESPIRATORY EXERCISES IN OTHER DISEASES. Eespiratory exercises may be employed with benefit in many other diseases than those ah'eady mentioned. To refer to some of these briefly. Gall-stones. — William Hunter has shown that catarrh of the gall-bladder and bile-ducts plays an important part in the causation of gall-stones, this catarrh in the case of the gall-bladder and large ducts being for the most part due to infection from the bowel, and in the case of the smaller ducts to the elimination by them of poisonous substances from the blood. The second great factor is sluggishness of the bile-flow, which favours the formation of gall-stones not only directly, but also indirectly, by inducing catarrh.* This second factor we can do a great deal to remove. There are several mechanical interferences with the active flow of bile. Such are : a lax state of the abdominal walls, which allows ' the liver to fall down, so that the fundus of the gall-bladder is considerably below the level of the junc- tion of the cystic duct with the hepatic duct ' (Hunter) ; a * Brit. Med. Jour., 1897, vol. ii., pp. 1235-1240. Hunter insists that ' stagnation alone is not sufficient to cause the condition.' That it is not a necessary factor is shown by the fact that gall-stones va&y occur in those leading active lives. I have recently had under observa- tion a man of fine physique and a champion runner who was suffering from complete biliary obstruction owing to the impaction of a gall- stone in the common duct. RESPIRATORY EXERCISES IN OTHER DISEASES 195 sedentary life, in which the liver is no longer shaken and compressed as it is by active exercise ; and interference with the proper abdominal breathing, during which the liver is rhythmically compressed between the diaphragm and anterior abdominal wall. It is probably in this way that pregnancy and tight-lacing favour the production of gall-stones. One half of the women whose livers show evidence post-mortem of tight-lacing are found to have them. From these considerations it is manifest that anything which favours the tiow of bile tends to check their forma- tion, and there is no more efficient way of doing this than by exercises of the diaphragm and abdominal muscles. We should also seek to prevent catarrh of the bile-ducts by keeping the alimentary tract in a healthy state. Finally, we should advise the drinking of large quantities of water ; for, as Lauder Brunton observes, sufferers from gall-stones are frequently very small drinkers. Obesity. — It is a well-recognised fact that obesity is pre- disposed to by defective oxygenation of the tissues. It is for this reason that the chlorotic have a tendency to plump- ness. It is not therefore surprising that respiratory exer- cises, by increasing blood oxygenation, should tend to pro- mote fat absorption. It should be remembered in this connection that great obesity favours the further deposit of fat by interfering with the respiratory movements, and thus with the proper aeration of the blood. Prolonged treatment by means of the compressed-air chamber reduces obesity. Anaemia. — Breathing exercises will be found of great service in the treatment of anemia, but especially of chlorosis. It is evident that whatever increases the amount of oxygen in the blood when this fluid is defective in it, must be of benefit. 1:3—2 ]96 EESPIRATORY EXERCISES Epistaxis. — For this a writer in the Medical Annual (1896, p. 290) recommends ' very rapid breathing with open mouth, the vowel A being enunciated with each expiration.' Stammering. — It is now known that many cases of stam- mering are due to faulty breathing, and in consequence they yield to breathing exercises systematically carried out. The diaphragm is often the muscle chiefly at fault. Hiccough. — An old-fashioned remedy for hiccough is to hold the breath for a time. The best plan is to take a series of rapid diaphragmatic breaths, holding the breath at intervals for as long as possible, with the object of breaking the convulsive habit of the diaphragm. Sleeplessness. — Deep breaths are very helpful in inducing sleep. INDEX Addomex, retraction of, 5H Abdominiil breathing, pure, 67 Abdominal nuiscles, action of, 15 effects of, on the circulation, 13 in maintaining the vis- cera in their proper position, 12 exercises for developing the, 160 means of testing the tone of the, 16 Abdominal viscera, effects of the respiratory movements on, 79 Abdommal walls, in the child, 17 in man and woman compared, 18 Active breathing exercises, 152 Allchin, 19;} Antemia, breathing exercises in, 195 Andral, 22 Arnold, 33 Asthma, breathing exercises in, 170 Barnard. Harold, 14, 24, 96 Blake, Edward, 96, 98, 153 Bloodvessels, compressibility of, 81 Bradford, 143, 144 Breath force, 43 in disease, 45 Breathing, modes of, 57, 61, 64 in singers, 64 exercises, 148 Breathlessness, influence of, on mean size of chest, 27 on respiratorv movements, 26 Broadbent, Sir William, 97, 110 ii, 120 Bronchitis, respiratory exercise in, 168 Brunton, Lauder, 13, 195 Budd, 176 H, 179 Cathcart, 67, 69, 71-73, 74 n Chapman, P. M., 83 ?^ Clarke, W. Bruce, 10, 12 (•lavicular breathing, 57, 64 Cheval, 72, 73 Cohnheim, 4, 143 n, 177 n ColUer, Mayo, 65 Compressed air, effect of innners- ing body in, 102 Costal breathing, influence of sex upon, 55 impediments to, 129 m the anthropoids, 55 varieties of, 57 how to learn, 150 Coughing, effect of, on intra-pul- monary tension, 112 Crying, the effects of, 125 Cycling, observations on, 163 Dean, 143, 144 )i De Jager, 81, 94 n I Density of outer air, influence of, 1 on the circulation, 101 198 INDEX Diaphragm, attachments and functions of, 50 strength of, 47 Diaphragmatic breathing, how to learn, 148 impediments to, 135 Digestive disorders, breathing exercises m, 192 Donders, 43 n Douglas-PoweU, Sir E., 4, 5, 21, 22, 54 n, 177 «, 181 Dyspnoea, 94, 142 influence of, in augmenting the mean size of the chest, 27 Effort, its influence on the cu'cu- lation, 113 Elasticity of the lungs, 1 means for maintainmg, 7 Elasticity of the thoracic cage, 19 ends served by the, 20 Elder, George, on the cranial cu'- culation, 98 Emphysema, breathing exercises in, 183 Emphj'sematous chest, 28 why it is expanded, 175 Expiratory force, 43 Expiratory and inspiratory muscles, relative strength of, 46 Fetzer, 35 Fixation of the chest, 31, 33 in emphysema, 176 influence of, on the circula- tion, 113 Foster, Michael, 81, 83, 88 Fox, Wilson, 29, 142, 175, 178 n, 181 Freund, 175 Gall-stones, breathing exercises in, 194 Guthrie, Leonard, 24 Hales, 43 it Heart, susceptibility of, to ex- ternal pressure, 82 j breatliing exercises in disease j of the, 185 HiU, Leonard, 13, 14, 24. 82, 96, 164 Hoist, Otto L., 159, 169, 170 Hoper- Dixon, 153 Hunter, William, 194 Hutchinson, John, 19, 33, 43 n, 54 n, 76, 77, 129 n Hyperoxygenation of the blood, effects of, 140 Impediments to the respiratory movements, 129 Inspiratory force, 43 Insphatory and expiratory muscles, relative strength of, 46 Intra-abdominal tension, 9 effects of, on circulation, 13, 90 Intra-pulmonary tension, modifi- cations in, 112 Jackson, Hughlings, 122 Jacobj', 170 Joal, 61 n, 64?/, 66-68, 70 « Jemier, Sir William, 177 7i Johnstone, Sir George, 144 Klein, 107 Lagrange, 26, 93 Laughter, the effects of, 125 Lees, D. B., 143 Ley den, 2 n, 5 Lower costal breathing, 57 Lungs, movements of, witliin the chest, 39 respiratory exercises in diseases of the, 166 Lymph, influence of the respira- tory movements on tlie circula- tion of the, 106 Lymphatics of lung and pleura. 106 McCann, 34 McKendric, 83 ti Mackenzie, Sir 3Iortl. 60, 65, 72 Mandl, 68 Marcet, W., 140. 171 Marey, 90 INDEX 199 Mean size of chest, factors deter- mining^ the, 25 Metcalfe, 171 Mobility of thoracic cage, ;52 means of testing the, 85 exercises for increasing the, 172 Morison, Alexander, 1415 IMountainous regions, the effect of, on chest-capacitv, 27 Miiller, C. W., 76 Miiller's experiment, 6 Muscle exercise, intluence of, on breathing, 111 Nervous mechanism of the re- spiratory movements, 52 Nervous system, respiratory exer- cises in diseases of the, 189 Obesity, influence of muscle activity on, 11 influence of, on the respira- tory movements, 130, 136 influence of, on the circula- tion, 137 breathing exercises in, 195 Oertel, 38, 95, 101, 124, 130, 187, 188 Pancostal breathing. 57, 65 Passive breathing exercises, 157 Perls, 4 Phthinoid chest, 27 Phthisis, respiratory exercises in the treatment of, 169 Pleura, the functions of the, 37 lower limits of the, 38 Pulmonary disease, breathing exercises in, 168 Pulse-rate, influence of the re- spiratory movements on the, 97 Pulse-tension, influence of the respiratory movements on, 94 Quain, 52 n Quantity of air that can be in- spired by the different methods of breathing, 61 Quincke, 2 n, 12 Earefied air, effects of, 102 Residual air, quantity of, 78 Respiratory force, 48 Respiratory movements, impedi- ments to the, 129 physiological modifications in the, 109 secondar^^ effects of the, 79 influence of, on the circula- tion of blood, 81 influence of, on the circula- tion of lymph, 106 Retraction of the abdomen, 58 Roberts, Frederick, 33 Rosbach, 118 Running, effect of, on the respira- tory movements, 93 Salter, Hyde, 111 7i Sanderson, Burdon, 54 n Sandow, alterations in the chest capacity of, 36 Savory, Sir William, 113 Sex, influence on the breathing, 55 Shouting, the effects of, 121 Sibson, 22, 38, 79 n, 80 Singers, breathing in, 64 Singing, the effects of, 122 Sleep, influence of, on the respira- tory movements, 110 on the circulation, 110 Sneezing, effects of an intra- pulmonary tension, 112 Stays, Nature's, 16 effect of removing, on the circulation, 13 Strength of inspiratory and ex- piratory muscles compared, 46 Suction, pulmonax-y, 1 its influence on chest capacity, 25 in emphysema, 175 in phthisis, 26 m well-developed lungs, 26 influence of, on the circula- tion, 88 Talking, the effects of, 118 Thoracic cage, mobility of, 32, 35, 172 Thorax, factors determining the mean size of the, 25 mode in which the, is en- larged, 54 200 INDEX Tightlaciiig, 13, 96, 131, 133 Transverse abdominal muscles, action of the, 13, 15 Treves, 12 Valsalva's experiment, 7 Vascular tension, influence of the respiratory movements on, 94 Vierorclt, 78 Vital capacity, 75 Volition, influence of breathing on, 141 Vomiting, influence of, on the circulation, 112, 113 Waldenburg, 43 ;/, 76, 101, 104, 182 n Weber, 95 Wintrich, 76 Yawning, effects of, 127 THE END. 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