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ADDITION TO NOTE AT PAGE 17. 



IF the atmosphere possessed, in its whole extent, the 

 same density as it does on the surface of the sea, it would 

 have a height of 24,555 Parisian feet; but it contains the 

 vapour of water, so that we may assume its height to be 

 one geographical mile = 22,843 Parisian feet. Now the 

 radius of the earth is equal to 860 geographical miles ; 

 hence the 



Volume of the Atmosphere =9,307,500 cubic miles = cube of 210-4 miles. 

 Volume of Oxygen . . =1,954,578 cubic miles = cube of 125' miles. 

 Volume of Carbonic Acid = 3,862-7 cubic miles = cube of 15*7 miles. 



The maximum of the carbonic acid contained in the 

 atmosphere has not here been adopted, but the mean, which 

 is equal to 0-000415. 



A man daily consumes 45,000 cubic inches (Parisian). 



A man yearly consumes 9505-2 cubic feet. 



1000 million men yearly consume 9,505,200,000,000 

 cubic feet. 



1 cubic mile is equal to 11,919,500,000,000 cubic feet. 



Hence a thousand million men yearly consume 79745 

 cubic miles of oxygen. But the air is rendered incapable 

 of supporting the process of respiration, when the quantity 

 of its oxygen is decreased 12 per cent.; so that a thousand 

 million men would make the air unfit for respiration in a 

 million years. The consumption of oxygen by animals, 

 and by the process of combustion, is not introduced into 

 the calculation. 



C C 



