63 



subject, their size, in the living subject, is 

 equally the same, whether healthy or diseased; 

 for no vacuum can exist between the lung's and 

 the surface of the chest. 



No animal can be healthy that does not enjoy 

 free respiration. Hence, tJie digestive powers 

 of the stomach, being weaker in horses that 

 are broken-winded, flatulency takes place, and 

 the air which is accumulated in tlie intestines, 

 makes its escape backwards whenever the 

 animal coughs. From this circumstance arose 

 the ridiculous custom of makino-an artificial or 

 supplementary anus, by dividing the sphincter 

 ani, with a view to let the wind escape more 

 readily. 



Hor'ses that are great feeders never breathe 

 freely until they have gone a mile or two, or 

 begin to sweat; but many of this description 

 are sometimes stouter horses in constitution, 

 and able to perform more work, than others that 

 do not labour under the same difficulty. Tlie 

 variation of the atmosphere will also have con- 

 siderable influence on respiration. Thus a horse, 

 beino- brouo'ht out of the stable in a cold foo-o-y 

 morning, will agitate his nostrils so as to pro- 

 duce a kind of half snorting sound at e\ery 

 action of his lungs. Rut it would be unfair to 

 deem either of the above cases as constituting 

 unsoundness. 



