Volume 3

A system of practical medicine : comprised in a series of original dissertations / arranged and edited by Alexander Tweedie.

  • Tweedie, Alexander, 1794-1884.
Date:
1840
Catalogue details

Licence: Public Domain Mark

Credit: A system of practical medicine : comprised in a series of original dissertations / arranged and edited by Alexander Tweedie. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

    28/402 (page 16)
    But the most perfect and equal crackling is that of peripneumony, and is therefore called the crepitant rhonchus; it exactly resembles the sound pro- duced by rubbing slowly and firmly between the finger and thumb a lock of one’s hair near the ear. We believe that this sound depends on the forcible passage of air through a little viscid mucus in the finest tubes, narrowed by congestion and deposit around them, but we shall have occasion to investigate this subject under the head of Pnkumonia. Of all these difierent rhonchi, we may repeat what we said of the morbid sounds of respiration, that they may occupy the whole of the respiratory move- ments, or be confined to part of them. Thus, an obstruction which is sufficient, at the commencement of inspiration, to cause a rhonchus, may be insufficient when the tubes are dilated by the distension of a full breath, or there may be the converse ; an obstruction which is total in low degrees of respiration and stops all sound, in forced or extensive efforts, as in coughing, occasions a rhonchus. This suggests to us the propriety of using these different degrees of respiration to test the nature and extent of bronchial obstructions. It may also be inferred from what has been said, that the different stages and degrees of force in respiration may change the note of the different rhonchi, and thus produce such a variety as that which we hear in the chests of some catarrhal and asthmatic patients. Laennec used to call this combination of piping sounds rhonchus canorus. It may be readily conceived, too, that these several rhonchi may be variously combined, or exist at the same time in different parts of the lung, and give rise to numerous combinations which it is needless to dwell on. It has been stated that the loudness of a sonorous or sibilant rhonchus is no proof of the severity of the disease ; nor is the fact of its being audible over the whole chest, unless the respiratory murmur be at the same time absent or very feeble in parts. But the presence of the bubbling or crepitant rhonchi does imply mischief proportioned to its extent; and if they are heaid over a large space, and accompanying the whole act of lespiration, diminishing oi destroying the natural murmur, they denote disease of a very serious character, because, as our hearing informs us, there is an obstructing liquid in the tubes where there ought to be only air, and the function of respiiation must be in- jured in proportion. . i i x- Auscultation of the voice. We now proceed to examine another class ot sounds — those of the voice as transmitted through the chest. We have found that the sounds of respiration, which are chiefly produced by air passing in the lungs, are transmitted to the air on the surface of the chest. In like manner the sounds of the voice, which are strongly communicated to the same air, are transmitted modified by the size of the tubes, and the nature of the substance through which they pass ; and thus these sounds also become signs of the con- dition of the organs that transmit them. . j- -1 1 On applying the ear to the throat or upper part of the sternum of an individual whilst he is speaking, the voice is heard so loud that it seems as if he w'ere speaking into the ear, only the articulation is not so distinct. 1 he reason of this is obvious : the sound of the voice, although originating in the vibration of the glottis, is propagated to the air above and below it; that below, being pent up is not heard without bringing the ear into contact with the parts where the tubes run, and it there resounds with all its force. This is called tra- cheophony, or the natural tracheal voice. , . But when the trachea divides and subdivides, there is not only a division of the sound into smaller tubes, and a consequent diffusion of it and reduction of its strength, but at this division the tubes plunge into the spongy tissue ot the lung which, as we have before found, is a bad conductor, and tends to stop the sound Hence over the chief bronchial ramifications, as on each side ot the unner part of the sternum, at and between the scapulsc and in the axillse, the voice is still heard, but more diffused and distant than at the throat and steiTiuin, and the articulation is still less distinct. This is natural bronchophony, or bronchial resonance.