70 THE NATURE AND TEEATMENT OF 



insure combustion in the lungs, passes through the delicate 

 lining texture of the pulmonary cells, exhausts the carbon and 

 eliminates carbonic acid gas. The venous blood is thus de- 

 prived of its defiling elements and becomes oxygenized — 

 acquires an arterial hue. This is precisely what takes place 

 in the common stove when charcoal is used as fuel. Charcoal 

 in ij;s crude state may be compared to venous blood, unfit to 

 impart heat or vitality, until ignited or brought in contact with 

 oxygen, then carbonic acid gas is evolved. The burning car- 

 bon acquires a red appearance, like arterial blood, radiating 

 its life principle, oxygen, to surrounding bodies, while its dele- 

 terious properties, like those evolved from the lungs, mingle 

 M'ith the atmosphere and render it unfit for the purpose of res- 

 piration. Here lies the " ^awe ;" the " antidote " is simple — 

 consisting of nothing more than pure air. 



Now, suppose for example, we rate the number of res- 

 pirations in a healthy horse at 17 per minute, and the con- 

 sumption of air every time the lungs are inflated, at 80 inches ; 

 it requires 1360 cubic inches of air to vitalize the blood. So 

 that in the course of an hour one pair of lungs will, at this low 

 estimate, vitiate an immense volume of atmospheric air. 



The fatal effects of breathing such an objectionable atmos- 

 pliere, as is too often found within our barns and stables, may be 

 made the subject of a very simple yet convincing experiment. 

 Take, for example, a glass jar of about two quarts, capacity, 

 turn it mouth downwards, and place within it a live bird or 

 mouse. At fii-st the imprisoned animal experiences little in- 

 convenience, but in proportion as the consumption of oxygen 

 and liberation of carbonic acid gas proceeds, the creature 

 begins to show symptoms of uneasiness ; the respirations be- 

 come accelerated, and in the course of a short time it dies as 

 if drowned or strangulated. Now it requires no great stretch 

 of the imagination to liken a tight barn or stable, having 

 nc provision for the exit of impure nor admission of pure 

 air, to the glass jar ; the air-tight barn is to the cow, just what 

 tlie jar proves to be to the bird or mouse. The latter die 

 quicker, and thus endeth their siuTerings; but the poor swill- 



