442 DISEASES OF THE RESPIRATORY ORGANS. 



The gurgling noises, it lias been suggested, arc due to the 

 disentanglement of air from the effused material in the form 

 of bubbles, or they may be the result of sounds generated else- 

 where, and propagated through the partly condensed and 

 partly fluid contents of the sac. 



F. Cough Resonance. — Some further indications of diseased 

 conditions, as revealed by sound, may in certain instances be 

 obtained by causing the animal affected to cough ; the sound 

 of which is propagated through the air contained in the 

 minute air-tubes to the surface of the chest. 



In health, the sound elicited is of a soft, dull, indistinct 

 character. In consolidation of the pulmonary structures, the 

 result either of hepatization or of compression from effusion, 

 the sound, as heard by the application of the ear over the 

 chest, and resulting from enforced coughing, is somewhat 

 louder and harder, and is communicated to a more or less 

 extensive surface according to structural changes. 



In cases following the progress of gangrene, or other de- 

 structive changes, where previously the ' cavernous rhonchus ' 

 formerly spoken of was heard, a considerable modification in 

 sound is obtained. It is generally of greater resonance, vary- 

 ing in accordance Avith the extent of the cavity in the lung, 

 and with the nature of its communication with the bronchi 

 and its position as related to the surface. 



CHAPTER XV. 



OF CERTAIN SYMPTOMS ASSOCIATED WITH CHANGE AND DIS- 

 TURBANCE OF THE RESPIRATORY ORGANS. 



In addition to the physical signs of change and disturbance in 

 the organs of respiration, there are also presented for our con- 

 sideration some not unimportant symptoms associated Avitli 

 these organs which will be useful to notice, however shortly. 

 These are grunting, coughing, dyi<pnoea, roaring, whistling. 



Any, or probably all, of these conditions may exist as tem- 

 porary infirmities, the result of very varying causes, and of a 

 nature not likely to be persistent, but removable by therapeutic 



