128 MANUAL OF EQUINE MEDICINE. 



larynx or lungs, but auscultation will tell us where the 

 sound is produced. 



Snoring is diagnostic of polypus, and snuffling sounds 

 indicate some disorder, accompanied by discharge from the 

 nose, such as catarrh, purpura hsemorrhagica or glanders, 

 scarlatina, etc. 



A dry wheezing or whistling sound, which persists, 

 indicates narrowing of the aperture of the larynx. 



In some cases of asthma a wheezing vibratory noise may 

 be heard along the trachea. 



2. In the Bronchi and Lungs. — In ausculting the chest, 

 the normal respiratory murmur may be heard to be aug- 

 mented, and this augmentation may be local or it may be 

 general. 



A general increase may be heard as the result of anything 

 which for a time enhances the activity of the breathing. 

 When it is increased over the surface, as the result of the 

 exclusion of air from a neighbouring portion of the lung, 

 it is termed supplementary. When heard over parts of 

 the chest, where it is not audible in health, the murmur 

 indicates an infiltration or solidification of the pulmonary 

 tissues. 



The respiratory murmur may also be diminished, and 

 this diminution may likewise be partial or general. 



General diminution may be due to various causes, for 

 example, to lessened respiratory action, such as occurs in 

 many cerebral disorders ; or it may be due to obstructions, 

 by which the normal expansion of the chest is lessened. 

 The murmur may be entirely suppressed from a variety of 

 causes. The suppression is one of the signs of consolida- 

 tion of the pulmonary tissues and of pleural effusion. 



Again, the murmur may lose its regularity and rhythmic 

 character. It may become oscillating or interrupted in 

 various ways in certain phases of pleurisy, or the expiration 



