Diseases of the Respiratory Organs. 93 



mit the air from without -while the chest is dilating, but 

 close like a valve when it is contracting. A little thus 

 entering with each breath and none escaping, the lung 

 is soon compressed into a small solid mass against the 

 lower end of the windpipe. The same may happen from 

 a broken rib having torn the surface of the lung even 

 without any external wound. A little air escaping from 

 the lung with each respiration the cavity soon becomes 

 filled and the lung compressed and collapsed. 



Treatment is limited to the prevention of the introduc- 

 tion of air through an external wound, should such exist ; 

 the relief of pain by opium and other anodynes ; the man- 

 agement of the resulting pleurisy on ordinary principles ; 

 and the drawing off of the accumulated air by a needle- 

 like tube and aspirator, or even by a small cannula and 

 trocar. Spontaneous recovery often takes place, the 

 wound being closed by inflammatory exudation and the 

 air absorbed. In cases dependent on decomposition of 

 the products, both gas and hquid should be drawn off and 

 a weak solution of carbolic acid (one part to two or three 

 hundred water) thrown in, in small quantity. 



ABSCESS OF THE INTEECOSTAL SPACES. 



This occurs especially in the horse as a result of pleu- 

 risy, a diffuse swelling appearing at some part of the walls 

 of the chest, tender and pitting on pressure, and, finally, 

 softening in the centre, bursting and discharging a yellow- 

 ish or whitish matter. The patient should be weU fed, 

 and poultices or warm fomentations continuously apphed 

 to the part until there is softening in the centre, when it 

 may be freely laid open. Continue to support the patient 

 by nourishing food, stimulants and tonics. 



DBOPSY OP THE LUNG. 



This is mainly a result of valvular and other diseases of 

 the heart. To percussion and auscultation it gives nearly 

 the same symptoms with pneumonia, but there is an (mtire 



