436 DISEASES OF THE RESPIRATORY ORGANS. 



numerous cerebral disturbances, marked by diminished respi- 

 ratory activity. Also, it may exist in consequence of certain 

 mechanical interferences or obstructions by which the normal 

 expansive capability of the chest is lessened. 



(3) Sui^pression or Absence of the Respiratory Murrtiur. — 

 This may be permanent or intermittent ; and is an accom- 

 paniment of conditions similar to what are encountered in 

 diminution of respiration. It is valuable as a sign of pleuritic 

 effusion and lung-consolidation. 



b.' Alterations as to Extent or Area of Lung -structure over 

 which the Respiratory Sound is Heard. — These may include 

 an extended or diminished area, according to the expansion of 

 lung-tissue and condition of the thoracic walls. 



c. Modifications as to Regidarity or Rhythm. — The disturb- 

 ances in the regular or rhythmic movement of the respiratory 

 murmur which may be noticed in the horse are : 



(1) The oscillating or jerking, in which the respiratory 

 murmur is interrupted or broken in various ways, seen in cer- 

 tain stages of pleuritis. 



(2) The unequal, where the one part of the act, that accom- 

 plished during expiration, is unequally prolonged, bearing a 

 marked disproportion to the inspiratory action. This is often 

 detected over the middle section of the thorax in emphysema 

 of the lungs. 



d. Alterations as to Quality or Character — The changes 

 which we group under character of the sound are various ; 

 these, besides being altered in sonorousness, pitch, and regu- 

 larity, have other peculiarities attached to them, all rendering 

 them of importance in directmg our diagnosis of disease. In 

 character we may have the respiration — 



(1) Harsh or Rough. — This is simply the respiratory murmur 

 of a higher pitch and of greater intensity, with the soft breezy 

 character replaced in part by a blowing sound. It is more 

 prolonged in expiration than inspiration. 



This sound seems to indicate moderate changes of consistence 

 in lung-tissue, as trifling compression in the early part of bron- 

 chial and pneumonic inflammations. 



This harsh or broncho-vesicular respiration, if not gradually 

 subsiding and replaced by the normal vesicular murmur, 

 steadily becomes fainter, and is replaced by another sound. 



