6 COMPENDIUM OF THE VETERINARY ART. 



the pleura, which will be blown up, and ap- 

 pear like an inflated bladder on the surface 

 of the lungs. If this be punctured, the air 

 will soon escape, and the lungs will return to 

 their original size. This circumstance is no- 

 ticed, as it is supposed to happen spmetimes in 

 the living animal, and to be the cause of broken 

 wind. (See Broken Wind and Chronic Cough.) 

 The lungs are divided into two parts, or lobes, 

 one of which is situate in each cavity of the 

 thorax : this division seems to have been pro- 

 vided in case of accidents, it having been 

 proved, that when one lobe is incapable of per- 

 forming its function in consequence of injury 

 or disease, the other has been found adequate 

 to the support of life. 



The lungs are the organs of respiration or 

 breathing ; but they do not appear to be actively 

 concerned in the performance of this oflice: 

 when the diaphragm and the muscles of the 

 belly and ribs contract, the cavity of the 

 thorax is considerably diminished, and the 

 lungs so compressed, that all the air contained 

 in them is forced out through the windpipe ; 

 when this has been effected, the muscles relax, 

 and the thorax returns to its oriq-inai size. 

 There would now be a vacuum between the in- 



