110 DISEASES OF CATTLE. 



dition can be easily diagnosed by physical signs. A loss of the respi- 

 ratory murmur \vill be noticed on auscultation, and on percussion dull- 

 ness or flatness on a line as high as the effusion has taken place. 

 When there is a large amount of effusion present, tapping with the 

 trocar and canula is generally resorted to. The proper method of per- 

 forming this operation will be found uuker the head of Pleurisy. 



PNEUMOTHORAX. 



Aii accumulation of gas in the pleural sac is known as pneumothorax. 

 The presence of air may either result from an injury of the lung or a 

 wound communicating from the exterior. The indications for treat- 

 ment are to exclude the further entrance ,of the air into the cavity by 

 the closure of the external opening. The air already in the cavity will 

 in most cases be absorbed. 



