THE IIORSE-KEEPER S GUIDE. 



283 



other sort of gas, which is expelled by his nostrils, termed 

 carbonic acid gas, and which contaminates and makes im- 

 pure the air into which it is breathed. Without a contin- 

 uous supply of good air, it is impossible for the purity of 

 the atmosphere of the stable to be maintained ; and unless 

 it be kept up, the blond of the animal which inhales an 

 impure air, becomes vitiated, and the system diseased ; <jr, 

 in other words, the horse becomes predisposed to a num- 

 ber of diseases, and his constitution is readily acted upon 

 bv any change in the weather, or other exciting causes, 

 that under a more healthy state of the blood, would not af- 

 fect the animal. 



Having shown some of the evil consequences of a \vant 

 of ventilation, we now proceed to advise as to how this de- 

 sirable end may be obtained. Many orrooms acknowledge 

 that the stable is too hot ; and to remedy the inconvenience, 

 make holes in the door or walls, to cool it. Now this is 

 only an aggravation of the previous evil : it is not cold 

 draughts oFair that will do any good— they rather do _mis- 

 chief^in producing colds, coughs, and a host of other disea- 

 ses of the chest and lungs : it is the purification of the at- 

 mosphere that is required, that the horses may breaths a 

 pure and not a tainted air. 



We have shown that the atmosphere of a stable, under 

 the most favourable circumstances, does not contain moie 

 than one part out of three of pure oxygen, the gas essen- 

 tial to health and life ; we have also shown that the horse 

 inhales a portion of this oxygen every time he breathes, 

 and that he exhales from his lungs another kind of gas, 

 termed carbonic acid gas, which mixes with the air of tlie 

 stable, and deteriorates its purity. Ventilation, properly 

 effected, will remedy this defect, or impurity, by allowing 

 the escape of the impure air, and substituting good in its 



stead. ^ 



The impure air which is exhaled from the horse s lungs, 

 IS necessarily warmer, and of course lighter, than the sur- 

 rounding atmosphere ; for this reason, it ascends or rises 

 "jpwards: if there be means for its escape, it will do so j 

 .f there are no such means of escape, it becomes cooler, 

 and so soon as it loses its heat it descends, mixes with the 

 air which fills the lower part of the stable, and is breathed 

 and re-breathed again and again, until so little pure oxy- 

 een is left in the air of tlie stable, that the quantity which 

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