POSTERIOR AND LATERAL REGIONS OF THE CHEST - in comparing together the amount of percussion resonance and the modification of breath and voice-sounds, we find ourselves much limited by the various circumstances already mentioned as interfering with the application of percussion at the lower por tions of the chest, and the indistinctness of its results upon the scapula; but here we have fortunately to deal less with disease of small amount and limited extent, more with general conditions of whole lobes, or the entire side of the chest. The breathing differs in intensity most materially in different patients, and the student should first endeavor to catch the sound about the inner edge and angle of the scapula on the healthy side, if he suspect one to be diseased ; then to compare this with the other ; from thence he may trace it upwards and downwards, and to either side, listening at the same time to the sound of the voice. It is a good plan to get the patient to talk continuously on some sub ject; because, not only is the voice thus heard, but at the end of each sentence a deeper inspiration is made, which thus becomes audible, when, as sometimes happens, the natural murmur is so weak as scarcely to be heard at all: practically, I think this plan more convenient than causing him to count one, two, three, &o., as many auscultators do ; the latter gives more equal intensity to the sound of the voice than general conversation, but minute dif ferences in vocal resonance are not of much value ; it is important, however, in all cases to hear the natural respiration if possible, without the intermixture of the sound of the voice.
§ 1. Percussion elicits a marked difference in resonance between the two sides, with much resistance on the duller side.
A. There is no breathing at all to be heard at the base of the lung, on the dull side; at a higher level, varying in different cases, it first becomes audible; and at the upper part prolonged expiration is heard louder on the dull side posteriorly just as it • is in the clavicular region (Div. I., § 1, A): the voice-sound is exaggerated and ringing at the upper part, and at one particular elevation it has a peculiar tremor and shakiness, which has re ceived the name of sagophony. These circumstances indicate
that the absence of breath-sound is caused by the effusion of fluid and consequent compression of the lung.
B. The breath-sound is nowhere wholly inaudible, or at all events is heard so low down that there must be a doubt whether it be anywhere abolished; it has a blowing sound, and is harsh and distinct, the expiration being especially prolonged; the voice sound is heard low down in the chest, with a ringing, brassy quality, which is constantly taken for sagophony, but it is diffuse and nowhere exhibits the true characteristic vibration of that sound. It is to be observed that the marked dulness and resist ance are more than consolidation alone could produce, and yet the characters of the voice and breath-sound are such as have been already mentioned as indicative of increased conducting power of lung-tissue by which the sounds produced in the larger tubes are conveyed to the ear; it is, therefore, reasonable to con clude that there is effusion of fluid along with consolidation of lung.
c. In chronic cases, the breath-sound may be nowhere inau dible, with considerable dulness on one side, when the want of resonance is caused by a thickened pleura after an attack of pleurisy has subsided. It is chiefly marked by the extent of surface over which the dulness is traceable, while the breathing is pretty uniform throughout. When the subjacent lung is healthy, the breath-sound is only weaker than that of the oppo site side; when other signs of disease are present, it may be a cause of considerable obscurity.
D. The percussion sound is superficially somewhat resonant, but very distinct dulness is observed when the stroke is firm and forcible; the breath and voice-sounds are not much changed, ex cept that the vesicular breathing is generally weak on the affected side, and is combined with a sound of distant blowing. The phe nomena are the same as those referred to in the clavicular region (Div. I., § 1, B, c); and the diagnosis of deep-seated tumor, so far as auscultation is concerned, really rests simply on such a state of things being found pretty generally throughout one lung.