^^5^ JA«?aSS IxJ^lV 63 



would require 5';; full pails of fresh air each minute, or a total of 7,718 palls 

 each t\venty-four hours. 



This amount of fresh air would contain 3 pails of carbon dioxide; after the 

 co\\- breathed the air it would contain 307',; pails of carbon dioxide; and 

 almost a pail of water would be gnen off by the cow through her lungs and 

 pores. 



A cow consumes TWICE the WEIGHT of pure air that she does of 



FOOD AND WATER COMBINED. 



Can \ou realize what an amount that is? 



Pile up a days ration of hay and silage and grain; beside it put the pails 

 of water a cow will usually dnnk. in a day. 



The WEIGHT of that food and water equals just about ONE-HALF 

 the WEIGHT of the air the cow requires during the twenty-four hours. And 

 that IS figured on the basis of pure, fresh air at that. 



To phrase it in another \\'ay : 



The a\ erage co\\- requires for six months" rations about 2' i tons rough 

 feed. 3' 1 tons silage, I ton concentrates and 13' i tons \\ater, a total of 

 201 , tons, or 41,000 lbs. 



For the same period, the cow requires 82,000 lbs. of air, or 41 tons. 



The 20' 2 tons of feed each, above mentioned, for 20 cows would fill 

 40,000 cu. ft., or the loft of a barn 36 ft. x 60 ft. with 14-ft. side posts and 

 gambrel roof. 



The 41 tons of air each for 20 cows \vould fill the loft of such a barn 

 36 ft. wide with 14-ft. side posts and gambrel roof, 10 miles long. 



The scientists tell us that air is not a simple substance, but consists of a 

 mechanical mixture of the gases oxygen and nitrogen with about I per cent by 

 volume of argon. Atmospheric air of ordinary purity almost always contains 

 a little carbon dioxide together with more or less vapor of water, and a very 

 acti^■e form of oxygen known as ozone. The a\erage composition of air is 

 gnen as follo\vs : 



Oxygen 20.588 



Nitrogen 76.765 



Carbon Dioxide 0.039 



Water 1.686 



Argon and other constituents 0.922 



100.00 



The air as thrown off by the lungs at 90 to 98 degrees Fahr. is nearly 

 saturated with water, and contains from 3 to 5 per cent carbon dioxide; hence, 

 it is from 1 to 3 per cent lighter than the air inhaled. 



