may change completely; the former, for example, being almost totally suppressed, while the latter becomes even peculiarly obvious. When the lung-substance is more or less impermeable, either locally or generally, and either from disease within itself or pressure from without, (as in cases of tubercle, pneumonia, pleurisy, pleuritic and pericardial adhesion, intra-thoracic tumour, aneurism, &c.,) this kind of perversion in movement will exist, either locally or generally, according to its cause. It is especially marked on forced inspiration; volition may drag the thorax upwards, but cannot expand impermeable texture. In vesicular emphysema, while the elevation-movements are carried to an extreme point, there may be no expansion at all (or even slight retraction) at the base during inspiration.

(c) The rhythm of the respiratory act is likewise subject to change; the duration of the expiratory movement may become considerably greater than that of the inspiratory. This is observed wherever material obstruction exists in any part of the passages from the nares downwards, to the exit of air from the lungs; and also (as in vesicular emphysema) where the elasticity of the lung is destroyed. In the latter affection the expirationmovement may be two-and-a-half times as long as the inspiratory.

(d) The proportion naturally existing between the extent and frequency of the motion of elevation on the one hand, and the duration and intensity of the respiratory murmurs on the other, may be altogether subverted; the former may be greatly increased in amount, while the latter have undergone remarkable diminution. This state of things constitutes one of the most remarkable features of diseases, where spasm affects the bronchial tubes or glottis, and obstructions of physical character exist in the larynx, trachea, or larger bronchi. The inspiratory action is abrupt and short, the expiratory prolonged.

(e) Again, the relationship of the thoracic and abdominal movements may change completely. Thus all conditions interfering, either dynamically or physically, with the movements of the diaphragm, while they impair these, give excess of energy to the thoracic class. Inflammation of the diaphragm, or of the serous membranes coating it, great fluid effusion in the pericardium, solid, fluid, and gaseous accumulations in the abdomen, pervert in this manner the natural order of things. On the other hand, the diaphragmatic movements may be increased by certain irritations of the phrenic nerves, in pleurodynia, intercostal neuralgia, the painful periods of pleurisy, in diseases or

injury of the spinal cord below the phrenic nerves, and (as compared with expansion-movement of the thorax) in obstructive diseases, functional or mechanical, of the air passages.

Before leaving the subject of inspection it may be as well to observe, that the undulation of fluid contained in the cavity of the pleura may be distinctly seen in some rare cases of considerable bulging of the intercostal spaces,-independently of perforation of the costal pleura, and escape of the fluid into the common cellular membrane. This is the only sign discovered by inspection which is not a modification of some natural condition.

SECTION II.-APPLICATION OF THE HAND.

By application of the hand and palpation, are meant the acts of laying the hand on, and feeling, the external surface of the chest. The object of these acts is to ascertain the form of the different regions of the thorax (little or no information can be derived from them regarding the general conformation of the cavity;) the state of the general, and especially of the partial, motions of the walls; the amount of vibration communicated under certain circumstances to the hand from those walls, and the existence or absence of fluctuation in the cavity of the pleura.

In employing this method of diagnosis, the palmar surface of the fingers and hand should be laid gently and evenly on the surface. If the object be to investigate the form or motions of the thorax, this is the only precaution, in addition to those recommended for the proper performance of inspection, which it is necessary to observe; if the thoracic vibration be the subject of examination, it is advisable to place the patient in the horizontal posture.

(a.) Application of the hand is less useful than inspection in ascertaining the amount of general motion, taken as a whole, existing in any given thorax; but it is greatly more effectual in distinguishing locally expansion from elevation-motion, and in analyzing the partial costal movements.

Thus in chronic pleurisy with retracted side, a good deal of elevation-motion may be felt during inspiration, while the total absence of any motion tending to fill out or expand the hand laid on the surface is readily ascertained. The same state of

things may constantly be established in the infra-clavicular regions, when the apex of the lung is consolidated. In this case and also in empyema, the thoracic walls, above and below the clavicle, may fall in during inspiration and expand during expiration, while the elevation-movement pursues its natural course and rhythm.

The sole means of accurately estimating the partial costal motions (those of the ribs in respect of each other) is by palpation. If the index-finger or thumb be placed in an intercostal space, anteriorly, of a sound chest, it will be found, that during inspiration the ribs diverge, and during expiration converge; the amount of divergence is obviously greatest in the lower interspaces, least in the middle ones. Allied in mechanism to the expansion-movements, these diverging-movements may nevertheless be affected differently from the former in disease. Thus, where the apex of the lung is tuberculized, the elevationmovement may, during inspiration, be still perceptible in the infra-clavicular region, and the expansion-movement be absolutely null, while the ribs actually converge. This inspiratory convergence of the ribs has appeared to me indicative of subjacent pulmonary consolidation and pleuritic agglutination combined.*

(b.) Tactile vibration, or fremitus.—If the hand be applied to the surface of the chest of a healthy individual, while speaking, a vibratile tremor is felt by the observer. This vibration, delicate under all circumstances and readily deadened by too forcible pressure of the hand, is, generally speaking, in the direct ratio of the graveness, coarseness of quality, and loudness of the speaking voice, and hence, as a rule, more marked in adults than in children, in males than in females. It is often

* Dr. Sibson (Med. Chir. Trans., vol. xxxi., p. 360) affirms that the five upper ribs converge during inspiration in the healthy state. I have never succeeded clinically in finding this, where the chest was sound, and very rarely where diseased. When a finger is placed in any upper intercostal space (the thinner the subject of the observation the better) it is compressed by the adjacent ribs during expiration, and relieved of all pressure during inspiration-just (though not to the same amount) as in the lower interspaces. Vide Appendix.

† In singing, the fremitus is much more marked when the voice is bass, baritone, or contralto, than when tenor or soprano; and it accompanies the lower notes of any given register to a much greater amount than the upper; it may be absolutely null on a high note, though most loudly sounded, while it is well marked with a low note of the same voice softly uttered. From a few trials, I find that the fremitus ceases with soprano and mezzo-soprano voices between ƒ and a on the lines: upper basses either retain the fremitus through their whole register, or lose it about their upper ƒ.

altogether deficient, indeed, in females, and habitually so in children. Cæteris paribus it is more intense in long-chested than in short-chested persons, and markedly so in thin than in fat people; unless as deepening the voice and either lessening or increasing fulness of person, age appears to have no influence upon its amount. The vibration is scarcely affected by tension or relaxation of the muscles over which the hand is land; in the great majority of cases it is stronger in recumbency than in the sitting posture (in twenty-two trials, sixteen times greater lying than sitting, four times equal, twice more marked in the sitting than the lying posture.) It is greatly more marked when some sounds are uttered than others, and hence the importance, in delicate comparative trials, of making the person examined repeat the same word or words.

As a general truth, the intensity of the fremitus is considerably greater on the right side of the chest than the left,-the greatest amount of this excess existing in the infra-clavicular, infrascapular, and inter-scapular regions. Exceptional regions are the right infra-axillary and infra-mammary, where the presence of the liver interrupts the vibrations, and throws into comparative prominence the naturally weak fremitus in the corresponding regions on the left side: the difference would be greater, were it not for the presence of the spleen in the latter position. Where the heart is uncovered by the lung, vibration is totally absent, and the right edge of that space may be traced by its abrupt cessation there; over the left lung there is naturally so little vocal vibration, that modifications of the sign can scarcely be used with confidence for making out the left edge. The lower border of the right lung may be traced by the abrupt cessation of all fremitus immediately below it.

The fremitus is intensely marked over the larynx and trachea, stronger at the sternal than the humeral halves of the infraclavicular regions, generally faintly manifest on the right clavicle, and imperceptible at the top of the sternum.

In Disease.-(a) The natural fremitus produced by speaking is susceptible of increase or diminution. As in the case of other signs, the existing amount of change is most effectually ascertained by comparison of the two sides of the chest; but in making this comparison, the observer must carefully bear in mind the great differences naturally existing on these two sides. Unnatural density of the pulmonary texture, produced by infiltration, unless this be carried to an extreme amount, intensifies

Vocal vibration-as in tuberculous or chronic plastic infiltration, and in acute hepatization: pneumonia of the left base posteriorly will thus raise the fremitus above the standard of the right base in health. Pulmonary apoplexy and edema act, within my experience, in the same way, but to a slight amount. In dilatation of the bronchi the increased calibre of the vibrating tubes, as well as adjacent consolidation, commonly tends to the same result. In pleuritic effusion occupying the lower part of the side, the infra-clavicular region may furnish fremitus in

excess.

When the lung-substance is removed to a distance from the chest-wall by gaseous or liquid accumulation in the pleura (as in pneumo-thorax, in pleural effusions, dropsical, hæmorrhagic or inflammatory) the fremitus is destroyed. The influence of solid accumulation (either in the lung or pleura) varies according to circumstances: very extensive lung-infiltration, whether fibrinoplastic, pseudo-fibrous, carcinomatous or other, deadens the vibration, especially if the infiltrated parts be distant from the larger bronchi; extra-pulmonary tumours and aneurisms produce the same effect. But if the other circumstances be favourable (such as the tone of the voice,) aneurisms, tumours and cancerous infiltrations will not, even when of tolerable size, annihilate fremitus, if they be in close connexion with the larger bronchi. It is commonly said that in vesicular emphysema the vibration is impaired; I have not found this habitual, and in some cases its intensity is above the range of health.

(b) The act of coughing produces a vibration similar to, but less marked than the vocal. This vibration (tussive,) suffers the same kinds of modification in disease; but it is valueless clinically, unless in cases of aphonia.

(c) Certain rhonchi throw the bronchial tubes into vibration sufficiently strong to be felt on the surface of the chest (rhonchal fremitus:) the sibilant, sonorous, and mucous, have all this property. The cavernous rhoncus, produced in excavations of the lung near the surface, may be accompanied with marked fremitus, and without fluctuation being perceptible to the finger. Stridulous respiration even (such as that attending aneurismal pressure on the trachea) may produce very distinct fremitus, greater in inspiration than in expiration.

(d) In the natural state of the pleura, the gliding motion of its costal and pulmonary laminæ upon each other gives rise to no vibration perceptible by the hand applied to the surface.