Sonorous • sounds, of a local character, sometimes exist along with the slighter dulness and exaggerated voice of early phthisis ; they greatly obscure the character of the breath-sound ; and in contrasting such a case with the next, it is of the utmost import ance to observe that they are heard on that side which is relatively the least resonant. Friction and creaking are both occasionally heard ; the former coexists with either form of consolidation, the latter always with tubercles : crumpling sound is generally re garded as a very certain token of tubercular deposit ; but to give force to either of these signs, the breath and voice-sounds should also be conformable to such an hypothesis.
B. When the lung, over which dulness is observed, happens to be healthy, the other being emphysematous, the absence of any superadded sound on the duller side, and the existence of sonorous sounds on the more resonant one, are important aids to diagnosis; but the latter are only audible when there is also bronchitis. They are not entirely limited to the clavicular region when em physema is present ; and this circumstance may be of use in judging of an obscure case, when a dilated bronchus produces auscultatory phenomena, resembling those of an empty cavity ; moist sounds may be heard with very severe bronchitis, but are never limited to the apex, and are generally audible there only at the very end of the expiration.
§ 4. No difference being detected in percussion resonance.
A. If the lungs be healthy at their apices, there will be no superadded sound. When very extensive bronchitis exists, both moist and sonorous sounds may be audible, but especially the latter: if either be heard at one apex only, while posteriorly the superadded sound, of whatever character prevails to about the same extent in both lungs, or if it continue to be heard at either apex after it has ceased in other parts of the chest, we have reason to suspect at least a tendency to phthisis, if not the actual pre sence of tubercle.
B. When both sides of the chest equally indicate increased resonance on percussion, in the clavicular region, a similar con dition is sure to be found in the rest of the chest. It very gene rally happens that a patient applying for relief in such circum stances is at the time also suffering from bronchitis, and sonorous, or sibilant, or even moist sounds, are to be heard on both sides ; and then their value in the clavicular region is chiefly negative, inasmuch as they are heard less distinctly there than elsewhere.
c. When both sides of.the chest equally deficient in reso nance, and superadded sounds heard in the clavicular region may also be detected elsewhere, they will consist of the varieties of moist sounds indicating bronchitis, or very generally distributed tubercular disease. The diagnosis between these states depends so much upon the contrast between the upper and lower portions of the lung, that their consideration must be postponed for the present. When the superadded sounds are confined to the apex,
there must be in reality a difference in percussion, and the case belongs to the next subdivision.
D. Some difference on percussion exists between the two clavi cular regions, but the ear fails in detecting it. To the student this class is necessarily a larger one than to the experienced aus cultator : it is one which repiires more than any other the exercise of careful discrimination in pronouncing a judgment, and it is important, because to it belong the instances of incipient disease. In no class of cases is superadded sound of more value in forming a diagnosis, provided it be taken in connection with the alteration of the breath and voice-sounds. Moist sounds, especially those which have a squeaking or clicking character when found along with jerking or wavy breathing, or prolonged expiration and increased vocal resonance, indicate most certainly the presence of tubercular deposit, which perhaps never affects both lungs equally. Coarse moist sounds, or anything approaching to gurgling, can scarcely exist without very decided dulness. Very fine moist sounds approach so near to crepitation that they are apt to be mistaken for it : if dulness be not pronounced, it is scarcely pos sible that such a phenomenon should find its explanation in the existence of pneumonia; a more probable solution is that capil lary bronchitis has been set up by the presence of tubercle. Sonorous or sibilant sounds, when only heard at one apex, are also evidence of local bronchitis ; and whether the prolonged sonorous expiration be due to the distension of the tissue by em physema, or its consolidation by tubercle, is a question that must be solved by the relative characters of the breath and voice-sounds detailed in the previous chapter. It is one of vast importance in diagnosis, which the character of the superadded sound alone cannot decide, and, in fact, any preconceived ideas of the asso ciation of sonorous sound with emphysema may very possibly lead us into error. A creaking or friction-sound, with exaggera tion of the voice and prolonged expiration, and still more de cidedly, a crumpling sound at either apex, are of much value in determining early tubercular deposit before dulness on percussion becomes very perceptible. The presence of any strictly local morbid sound at either apex, as it points out the certainty of structural change there, comes to have immense significance when other symptoms indicate the possibility of tubercular disease, and, still more, when the other indications of percussion and aus cultation give countenance to the idea of, consolidation at the apex, where the local sound is heard.