Diseases of the chest, throat and nasal cavities : including physical diagnosis and diseases of the lungs, heart and aorta, laryngology and diseases of the pharynx, larynx, nose, thyroid gland, and œsophagus / by E. Fletcher Ingals.

  • Ingals, E. Fletcher (Ephraim Fletcher), 1848-1918.
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: Diseases of the chest, throat and nasal cavities : including physical diagnosis and diseases of the lungs, heart and aorta, laryngology and diseases of the pharynx, larynx, nose, thyroid gland, and œsophagus / by E. Fletcher Ingals. Source: Wellcome Collection.

    50/710 (page 22)
    Pleximeters are made of various materials, as rubber, bone, -wood, ivory, or leatlier. Some of tliem are graduated in order tliat they may be iised in mensuration. The one which I think the best consists of a narrow oval disc of hard rubber, with large ears at each extremity. It should be narrow enough to be placed between the ribs, and should have a large projection at each end, that it may be firmly grasped. I have frequently used a small cylinder of soft rubber about two inches long and half an inch in diameter. It has the advantage of being easily adapted to the intercostal spaces, and of emitting no sounds of its own when struck. For ordinary percussion it is best to use the middle or index finger of one hand in place of the pleximeter, and two or three fingers of the other, with their tips brought into line, as a hammer. The fingers used as a plexor should be brought as nearly as possible to a right angle at the second joint, that the terminal phalanges may strike perpendicularly upon the finger of the opposite hand. When the fingers are used, there is noticeable a certain sense of resistance which is not obtained with instruments. Often this would enable us to detect internal organic changes even with our ears com- pletely stopped. So valuable is it in intricate cases that, when there is difficulty in making an accurate diagnosis, I always employ the fingers instead of instruments for percussion. The sounds obtained by percussion are generally described as clear dull and tympanitic, but these terms are not sufficiently precise to aid us much in studying the method. I prefer a classification based upon acoustic properties. The elements of sound which concern us m per- cussion are intensity, pitch, quality, and duration. , , • . ^ , The intensity of a sound determines the distance at which the sound may be heard. Other things being equal, the intensity of a sound n pulmonary percussion varies with the force of the blow, the volume of air in the lung, and the thickness and elasticity of the chest walL ft is diminished by thick layers of fat or muscle, by rigidity cosUl cartilages, and by contraction or consolidation of the lung, and it is m- creased by the opposite conditions. , , ti^m^p fnmil The pitch of a percussion sound maybe high or low. Thosefarnil- iar with music will understand this, but a ^ornrnon Me .s^^^^^^ found pitch with intensity. Many students ^^VV'^^.f^^''^^^^^ pitch, the greater the intensity. The reverse o ^ ^^^^^^^^^^^^ pulmonary percussion, intense sounds being low pitched, and high pitched sounds possessing feeble intensity. This difference between pitch and intensity can be e»ily striking two notes at opposite ends ot Ty^jf;/ Cbe heL some dis- high note forcibly, one w,ll obtam a so ind 1™^/Si „ ^t,,,,^ „ ,„„„<i tance-then by gently tapping a key at the othe. end, one wi S'at ex Jl^the san,e distance, but ol a much lower p.tch. The pitch of the percnssion note over a health, lung .» always low.