ON RESPIRATION. 125 



pand without forming a vacuum in the chest, 

 which the pressure of the external atmosphere 

 prevents, and which may be readily perceived 

 in the case of broken wind, for then the inter- 

 costal muscles are so strongly retracted, as to form 

 a deep furrow between every rib, as well as a de- 

 pression in the flanks. On this account, air is re- 

 ceived into the lungs with great difficulty, but 

 its expulsion is not so difficult as the return of 

 the ribs and diaphragm naturally force it out by 

 their pressure. Thus, in broken-winded horses. 

 Inspiration is very slow, but expiration is sudden 

 and rapid, as may be seen by the flanks return- 

 ing with a jerk. If there is water in the chest, 

 the horse never lies down, as the pressure which 

 would take place in that situation, would pro- 

 duce suffocation instantly. 



The foregoing are the general symptoms 

 attendant on broken wind : it remains to inquire 

 into the less violent affections of the lungs. 

 The most frequent of these are manifested by 



coughs. 



