198 AUSCULTATION. 



In immediate auscultation, the ear should be closely 

 applied over the surface of the skin, to prevent the entrance 

 of any extraneous sound. The right or left ear should be 

 employed, according as one or other can be most accurately 

 applied to the part, a preference being, at the same time, 

 given to that in which the sense of hearing is most acute. 

 If a cloth is placed over the skin, it should only be in a 

 single fold, since the rubbing of two folds on each other may 

 give rise to the production of adventitious sounds. In mediate 

 auscultation, not only must the funnel-shaped end of the 

 instrument be accurately applied to the chest, but the oppo- 

 site end ought to be likewise retained in perfect apposition 

 to the ear. The instrument should accordingly be applied 

 perpendicularly to the surface examined; it should be mode- 

 rately pressed, to diminish the bulk of the soft parts, and 

 fix it more firmly upon the solid structures beneath. Care 

 should be taken that no long hairs pass into the stethoscope, 

 and thereby modify the sound. 



In either case, the following precautions should be 

 attended to : 1st. A quiet place and time should be 

 selected. Thus, at an early morning or late night visit, there 

 will be fewer sounds to distract the attention, and such 

 accordingly are to be preferred. 2nd. In the summer season 

 we should endeavour to prevent irritation from insects, which 

 would excite movements entirely subversive of our efforts. 

 3rd. Auscultation ought not to be practised over any muscle 

 in a state of contraction, as the sound of the contracting 

 fibres is a frequent source of fallacy. In certain cases, where 

 the respiratory sounds are feeble or indistinct, they may be 

 rendered more prominent by exercise, which may be walking, 

 trotting, or galloping, according to the necessities of 

 the case. 



Each of the two methods of auscultation possesses merits 



