PHYSICAL SIGNS DRAWN FROM AUSCULTATION. 435 



Alterations in the tracheal sounds are chiefly the result of 

 the presence of adventitious materials in the tube. Where 

 liquids and mucus have been poured into the bronchi, the 

 natural sound is modified to a mucus rale, or probably it may 

 be more of a sibilant vibratory character depending on the 

 nature of the contained material. In some cases of asthma a 

 mild wheezing or vibratory noise may be plainly heard along 

 the whole tube. 



2. Lotver Air Passages, Thoracic or Chest Sounds. — The 

 abnormal thoracic sounds distinguishable are eithersuch as may 

 be viewed merely as altered normal sounds, or as sounds added 

 to the ordinarily existing ones, and of a different character. 



The vesicular or true pulmonic sound is liable to modifica- 

 tion — (a) As to its duration or intensity ; (h) As to its extent 

 or area over ivhich it may be heard ; (c) As to its rhythm or 

 regidarity ; (d) As to its quality or character. 



a. Changes as to Duration or Intensity. (1) Augmented. — 

 In this there is simply an exaggeration of the natural vesicular 

 sound ; it may be extensive or complete when it is spoken of as 

 general, and as partial when the increase is circumscribed ; 

 there is no variation in pitch or alteration in character. 



A general increase in the respiratory murmur will result 

 from any cause which for a time increases the act of breathing ; 

 it is observed in febrile disturbance 'per se, or when occurring 

 as a symptom of other diseased conditions. 



The term ' supplementary ' respiration has been given to in- 

 creased vesicular murmur over the whole or part of the lung- 

 surface, consequent on the exclusion of air by the existence of 

 some obstruction from a neighbouring portion of lung-tissue. 

 When heard over portions of the thoracic cavity, where in 

 health it is not usually encountered, it is indicative of the in- 

 filtration or solidification of pulmonary tissue, which thus be- 

 comes a better conductor of sound. 



(2) Diminution in the intensity of the respiratory murmur 

 may, like the opposite condition, be general or partial. General 

 diminution depends on many causes, and these are often such as 

 are not directly connected with thoracic changes ; very often 

 with diseased conditions of other and distant organs, which, 

 by nervous and other influences, operate indirectly on the 

 activity of the pulmonic function. Of this class are the 



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