PHYSICAL SIGXS DRAWN FROM AUSCULTATION. 437 



(2) Bronchial or Tabular. — This is the sound normally 

 heard in connection with the larger air-tubes, only now un- 

 usually marked and hard, where in health it is absent. It is 

 the characteristic sound of absence of vesicular murmur, the 

 result of condensation. The existence of this tubal sound in 

 pulmonic tissue, following upon harsh respiration, is indicative 

 of the blocking up of the small bronchi and air- sacs with the 

 products of the morbid action ; but it also tells that the air- 

 conduits somewhat larger are still pervious. It is also met 

 with apart from condensation of lung-tissue, being sometimes 

 heard as an accompaniment of emphysema. 



Other manifestations of this sound, varying according to 

 distribution and other relations, have been spoken of as hloiu- 

 ing, from the variation detected in their pitch and intensity. 



Also, in rare instances, from the connection of the air-tubes 

 with cavities as abscesses or vomicre, we have particular modu- 

 lations of sound, varied in accordance with the impression 

 which they convey to the ear, as cavernous or amphoric. 

 These sounds seem to be formed in accordance with the nature, 

 relative size, and position of these cavities, and their tubal 

 communications. 



However, from the physical difficulties in connection with 

 minute and discriminate auscultation in the horse, these varia- 

 tions are not so well established, and have received less atten- 

 tion with us than they have with the practitioner of human 

 medicine. 



C. RhoncM, Rales, or Rattles. — Besides these alterations of 

 the natural respiratory sounds already mentioned, there are 

 occasionally encountered in pulmonary disorders, and having 

 their origin in pulmonary tissue or air-tubes, a class of sounds 

 known by the name of ' Rales,' 'Rattles,' or ' Rhonchi.' 



Various classifications of these sounds, according to taste 

 and opinion, have been adopted. With too many and minute 

 divisions there is apt to be confusion. 



In further regarding these sounds, we purpose speaking of 

 them by the terms of ' Dry Rales ' and ' Moist or Humid 

 Rales, in accordance with the impression which is conveyed to 

 the ear of sound travelling along a dry surface or one covered 

 with fluid. 



1. Dry Rales, or Vihratonj Rdles. — These owe their exist- 



