Nor is it usual, even in cases where audible friction-phenomena exist, to discover such vibration: in some instances, however, it may be detected; and the sensation conveyed, though distinctly somewhat vibratile, nevertheless possesses more of a simply rubbing character, just as might be anticipated from a consideration of its cause,-the friction of plastic matter on the pleural surfaces. In point of intensity it varies greatly; in some cases perceptible, even in ordinary breathing, to the patient himself,-in others it is only evolved by forced inspiration, and only to be caught occasionally. Accompanying either the inspiration or expiration-movement, it is more commonly associated with the former. I have met with it to a higher degree at the absorption-period, than at the outset, of pleurisy. (e) A pulsatile movement of the lung, attended with a quasitremor on the surface of the chest, and synchronous with the systole of the heart, has been noticed (first by Dr. Graves) in some rare instances of pneumonia and intra-thoracic cancer. Here, too, may be included the impulse of pulsating empyema. Palpation may also be used for the detection of fluids contained either in the lungs or pleura. The sensation is that of ordinary fluctuation, attended (not always) with a certain degree of vibratile tremor. Its existence may be ascertained, either by the movements of the fingers used by surgeons for detecting fluid in an abscess (simple fluctuation;) or it may be necessary to perform succussion of the chest (fluctuation by succussion;) or percuss the surface, in order to produce it ("peripheric" fluctuation;) or it may occur through the influence of respiration as an attendant on cavernous rhonchi (rhonchal fluctuation;) in this latter case it is that vibration may be most distinctly felt. The "peripheric" species (described by Dr. C. Tarral) is to be detected by giving a quick, sharp fillip in an intercostal space, perpendicular to the surface, when a sensation of fluctuation will be transmitted to a finger of the other hand firmly applied to the surface in the same space, at a short distance from the point percussed. Simple fluctuation is producible, where the intercostal spaces are much bulged out by pleuritic effusion; peripheric fluctuation in the same cases, but most perfectly where air and fluid co-exist in the pleura; fluctuation by succussion in cases of hydro-pneumo-thorax and of large excavation in the lung. SECTION III.-MENSURATION. The object of measuring the chest is twofold; First, to ascertain, more accurately than can be done by inspection and application of the hand, the comparative bulk and volume of the two sides, the relative positions of their different parts, and, in some few instances, the distances between those parts and certain fixed points beyond the limits of the thorax (measurements in rest:) Secondly, to estimate with precision the amount of expansion and retraction of the chest accompanying inspiration and expiration (measurements in motion.) A complete system of Mensuration would comprise the following admeasurements: A. GENERAL.-(a) Circular. 1. On level of sixth cartilage: 2. Midway between nipples and clavicles. (b) Transverse. 3. From point of one acromion to that of the other; 4. In axillæ ; 5. At base of chest. (c) Antero-posterior. 6. Under the clavicles; 7. At base of chest. (d) Vertical. 8. From clavicle to most dependant point of ribs. B. PARTIAL. (a) Horizontal. 1. From nipple to middle line of sternum. (b) Vertical. 2. From middle of notch of sternum to nipple; 3. From nipple to antero-superior spine of the ileum; 4. From the most dependant point of the twelfth rib to the same spine. But these different kinds of measurement are not all of equal importance, especially in the present state of knowledge,—either because some of them really convey information of very secondary value, or because they have been not as yet sufficiently practised to render the physician familiar with the indications derivable from them. The measurements which it is of real consequence for the student to understand, and in all doubtful cases to practise, are distinguished by italics: at the same time, it would be a mistake to imagine that all the others may not occasionally furnish more or less useful information, either confirmatory or corrective of results otherwise obtained. § I.-MENSURATION IN REST. A. GENERAL MEASUREMENTS.-(a) Circular, (1.) on the level of the sixth cartilage.-Circular measurement of the chest, as commonly performed with a single graduated tape passed round the thorax from the middle line anteriorly, is a troublesome process, requiring the patient to be raised to the sitting posture, and the co-operation of two persons. Besides, the difficulty of ascertaining the precise point of the measure, corresponding to the spine, renders the process inaccurate. These difficulties have been removed by a very simple plan, suggested, I believe, by Dr. Hare, that of joining together two such tapes at the commencement of their scales, and fixing them, as the patient reclines, at their line of union, to the spine: each side of the chest has thus its separate measure. By padding the inner surface of both measures, close to their line of junction, a sort of saddle is made, which readily fixes itself to the spinous processes. - The circular capacity of the chest varies so widely in healthy individuals, that there is little practical utility in attempting to fix its mean value. I have known it in the adult male so high, on the level of the sixth cartilage, as forty-four inches, and so low as twenty-eight. Perhaps thirty-three inches may be mentioned as the fairest adult average; but it varies with age (long after the height has become stationary,) gradually increasing from the age of sixteen to sixty: so that the mean being thirty inches from the age of sixteen to twenty, it is thirty-four from that of fifty-one to sixty. The circumference increases, but not in any fixed proportion, with the robustness, stoutness, and height of individuals. The female circumference is, absolutely, less than the male. According to M. Woillez, the circumference is greatest in persons following trades that require active exertion of the whole frame, but not of the upper extremities in particular. Far from this, were his number of cases sufficient for the final decision of the question, the latter class of artisans must be held to have the lowest average circumference of thorax. But the absolute measurement is of less importance than might appear, for width is not an index of expansile power; far from this, these statical and dynamical conditions may (as in fat people especially) be inversely as each other. The relationship of pectoral to abdominal circumference varies with age. In infancy and childhood the latter is greater than the former; in the male adult (less so in the female) the chest exceeds the abdomen in width. In cases of abdominal obesity the natural ratio becomes perverted. The two sides of the chest are of unequal semi-circumference in about five-sixths of healthy adults; a mean excess of about half an inch existing on the right side in right-handed individuals;* in left-handed persons the left side sometimes measures more, or more frequently the same as, the right. These propositions hold true of both sexes; but the difference is slightly greater in males than females. In infancy and youth the two sides scarcely differ. I have not traced any special influence of trade on the measurements; but accidental circumstances (unconnected with disease of the thoracic organs) are liable to modify their ratio. Thus, distension of the stomach with flatus or food may equalize the measurement, for the time it lasts, on the two sides; and I am led to believe, from a case observed at University College Hospital, that the deficiency of motion, kept up by fractured ribs in some cases for a very lengthened period, perhaps for a life-time, may in the end diminish the dimensions of the side,-the lung probably (as in cases where its activity is impaired by bronchial pressure) becoming more or less atrophous, and the thoracic walls falling in proportionally.† The most important morbid conditions of circular dimensions are increase or diminution of width of either side, as compared with the other. They occur respectively in the same diseases (already enumerated under these heads) as morbid expansion and retraction. 2. Of circular width midway between the nipple and clavicle little is known. The scapulæ prevent the real measures from being taken, and in some persons raise the circumference here above that on the level of the sixth cartilage; as far as is now known, the ratio of the two circumferences does not appear to me sufficiently constant to be trusted to clinically. It is matter of general belief that the size of the upper part, compared with the base, is greater in proportion as the muscular and osseous systems, especially the latter, are strongly developed, and the constitution of the individual free from the taint of predisposition to phthisis. Though not prepared to say positively whether the excess of width, existing at the lower part of the chest on the This excess becomes more remarkable when the frequency of slight convexity of the dorsal spine to the right, in health, is considered. † Case of Bassett (Males, vol. ii. p. 214;) the right side (the man being right handed and free from pulmonary disease, capable of explaining the fact,) measured (opposite the sixth cartilage) 163 inches, the left 18 inches: he had old fractured ribs on the right side. ANE LIBRARY right side, holds here also, I am inclined, from a limited number of observations, to believe that it does, though to a less amount than inferiorly. (b) Transverse.-Respecting mensuration of the transverse diameters of the chest, I have no precise information to offer. It should be made with a pair of callipers, and there can be little question that diagnostic data of importance might occasionally be derived from its employment. It would, however, in the greater number of cases, do little more than confirm the results of inspection; for diminution of the transverse diameter, in respect of the antero-posterior, the change which, it may be presumed, would most frequently present itself, is one of those alterations of shape which most readily attract the eye. (c) Antero-posterior.-A pair of common steel callipers is the simplest instrument for determining the antero-posterior diameter of the chest. The difficulties, in comparing the diameters of the two sides, are to apply the blades of the callipers with exactly the same force, and (what is far from easy, on account of the slope of the surface of the chest,) to exactly corresponding points on both sides. In measuring the antero-posterior diameter of the apex of the chest on either side, the extremity of one blade should be placed immediately under the centre of the clavicle, the other upon the corresponding point of the spine of the scapula, the equi-distance of both extremities from the middle line being at the same time carefully ensured. The diameter of the right side in this situation (as also over the sixth rib) will be found, in the greater number of healthy persons, to exceed that of the left, but by so very small an amount that it need scarcely be taken into consideration where an excess at all marked is detected on that side. In other words, such an excess (for example, a fourth of an inch) on the right side, furnishes sufficient evidence of morbid depression or diminished diameter on the left: though the existence of a similar excess on the left will be still more strongly conclusive of contraction on the right. The morbid states discoverable by the measurement now described are, diminution and increase of the antero-posterior diameter. The latter change occurs in pleurisy with effusion, pneumonia, hypertrophy of the lung, emphysema, intra-thoracic tumour and aneurism, various heart-affections, and possibly at the very outset of tuberculization. Diminution, on the other hand, arises in the more advanced stages of tubercle, in simple chronic |