CHAPTER III 



METABOLISM 



Oxidation. It is known that oxygen exists in 

 two forms, ordinary atmospheric oxygen and ozone, 

 the molecule of the former consisting of two atoms 

 (written O 2 ), and that of the other of three (O 3 ). 

 During thunderstorms ozone is often formed from 

 oxygen by condensation, through the action of 

 electricity. Both gases are chemically active in 

 combining with other elements or compounds, a 

 process known as oxidation. The activity of ozone, 

 however, is much greater than that of ordinary 

 oxygen. It gives up its extra atom of O with facility, 

 and- is, therefore, spoken of as less stable than the 

 latter. But the resulting product of oxidation by 

 'either oxygen or ozone is 'exactly the same. The 

 only difference between the two must be the way 

 in which the atoms of O are combined to form the 

 molecule. In oxidation there is an evolution of 

 heat, which is the release of the intrinsic energy of 

 combination in the oxygen or ozone molecule. 

 Measurements have shown that in the oxidation of 

 finely divided platinum by ozone, some 72,400 

 calories 1 more of heat per gram is evolved than in 

 the corresponding oxidation by ordinary oxygen. 

 This figure must represent the additional amount of 



1 A calorie is the measure of heat required to raise one cubic centimeter 

 of water one degree. 



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