BROKEN WIND. 8. 



the most commua appearance of the hiogs in 

 broken winded horses is a gc;nerar thickenmg 

 of their substance, by which then' elasticity is 

 in great measure destroyed, and their weight 

 specifically increased, at the same time that 

 their capacity for air is diminished. During 

 Hfe the lungs entirely fill the cavity of the 

 chest, so as to leave no space between their 

 outward surface and the inward surface of the 

 ribs. (See Structure of the Lungs.) Thus 

 they dhate and contract, following up by tiieir 

 own elasticity the action of the ribs and dia- 

 pnra,gai. It the chest be punctured in the dead 

 Subject, the air rushes in, and the lungs col- 

 lapse : but if the horse were broken winded, 

 the lungs do not coDapse. This state of -the 

 lungs sul^cicnily acr-ounts for tiie cnfficultv of 

 respu'atijii ; for as thair JlicuLy tf dilatatmi is 

 destroy/, a, the ribs canuot expo, rid without form- 

 ing a -vacuum in the chest, which the pressure 

 of the external an' prevents, which luay be 

 reaciiiy perceived in die case of broken whid; 

 for then the inti^rcoscai muscies are to strongly 

 retracted, as to form a deep furrow betvveen 

 every rib, as well as a depression in the iianks. 

 On trtts account air is received into the lurni's 

 'WUit> ^leuL dijficuitjj \ utu as expulsion IS not so 



