A treatise on the diseases of the chest and on mediate auscultation / by R.T.H. Laennec.

  • Laennec, R. T. H. (René Théophile Hyacinthe), 1781-1826.
Date:
1827
Catalogue details

Licence: Public Domain Mark

Credit: A treatise on the diseases of the chest and on mediate auscultation / by R.T.H. Laennec. Source: Wellcome Collection.

Provider: This material has been provided by the Harvey Cushing/John Hay Whitney Medical Library at Yale University, through the Medical Heritage Library. The original may be consulted at the Harvey Cushing/John Hay Whitney Medical Library at Yale University.

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    Fatness, even when excessive, and anasarca of the chest, seem to have no effect in diminishing the pecuHar sound. The sound is more distinct in proportion as the respiration is more frequent. A very deep inspiration made very slowly will sometimes be scarcely audible, while an imperfect inspiration— such, for instance, as hardly at all elevates the chest, provided it be made quickly,—may produce a very loud sound. On this account, when examining a patient, more especially if we liave had but slight practice with the instrument, we should desire the respiration to be performed rather quickly. This is, however, a very unnecessary precaution in most diseases of the chest, as the frequent presence of dyspnoea necessarily renders the respiration quick. Tlie same is true of fever, and the agitation caused by nervous affections. Many other causes, and especially the age of the individual, alter the intensity of the sound. In chiklren, respiration is very sonorous, even noisy, and can be heard easily, even through very thick clothing. In them, the close and forcible application of the instrument, to prevent the friction of the garments, is unnecessary, as any noise that might arise from this cause is lost in the intensity of the other. The respira- tion of children differs, also, from that of adults in other re- spects besides its intensity. It is impossible to describe this peculiarity, but it will easily be understood by comparative trials, It appears as if, in children, we could distinctly hear the dilatation of all the air cells to their full extent j whilst, in adults, these seem as if, from their stiffness, they could only bear a partial dilatation. This difference of sound is much less marked in expiration than inspiration. The dilatation of the chest in inspiration is also greater in the child; and both tliese peculiarities are more remarkable as the child is young: tliey continue, in a greater or less degree, to the period of pu- berty or a little beyond it. The sound produced by respiration varies, also, very much in its intensity in different adults. In some men it is scarcely perceptible unless they make a very deep inspiration, and even then, although sufficiently distinct, it is not one-half so audi- ble as in the majority of persons. These individuals have ge- nerally a rather slow respiration, and are little subject to dysp- noea, or breathlessness, from any cause. Others, however, have the respiration very distinct even during a common in-