126 CLINICAL DIAGNOSTICS. 



confined to certain portions of a lung, 

 and is observed when the free entrance of air into the vesicles 

 is made difficult by a contraction or occlusion of the bronchi 

 (bronchitis ). 



b. Bronchial tones. The bronchial respiratory sound 

 is normal in the larynx and trachea ; i t s appearance in 

 the chest is always a sign of disease. It 

 is audible only when the bronchi are free and the vesicles con- 

 tain no air. 



Bronchial respiration displaces vesicular respiration : 



1. If .the vesicles are filled with exudate, therefore in all 

 pneumonias, especially in contagious pleuropneumonia of tlie 

 horse and in contagious pleuropneumonia of the ox. To be 

 heard, however, the hepatized portion of the lung must be of 

 the size of a double clenched fist and lie next to the costal 

 wall. 



2. If the lungs are compressed by pleuritic exudate 

 (atelectasis). The compression must be complete, for if the 

 vesicles contain air at all a feeble vesicular murmur can still 

 be heard. 



A special v a r i c t }• of bronchial r e s p i r - 

 a t i o n is the amphoric respiration, which is a bruit, of a char- 

 acter like the sound produced by gentl}- blowing across the 

 mouth of a narrow-necked bottle. In animals it is rare, l;ut 

 appears if large caverns in the lung communicate with bronch.i 

 (pulmonary gangrene ) . ( ) n percussion, i n p lace 

 of the d ul 1 e d s o u n d which is usual w h e n 

 the respiration is bronchial, a t }• m p a n i t i c 

 tone or a c r a c k e d - p o t resonance is heard. 



That bronchial respiration may become audible the bronclii 

 must not be occluded; if they are filled with masses of exu- 

 date, no respiratory sound is heard. A forcible cough, how- 

 ever, may dislodge and eject the exudate and the i:ronchi be- 

 come free a-^rain. 



c. The vague cr indefinite respiratory sounds. Sv;c!i 



