212 THE CHEMISTRY OF CREATION. 



of chemical combination. It might be thought 

 it was thus formed, possibly with a view to 

 facilitate the innumerable decompositions into 

 which the gases of the air so largely enter. 

 When we remember with what extreme dif- 

 ficulty a true chemical compound of oxygen 

 and nitrogen gases is decomposed, the dissolu- 

 tion of union only taking place under the force 

 of violent chemical reactions, we believe there 

 is sufficient cause for admiration that the wisdom 

 of the Creator has otherwise ordered the com- 

 position of the air, in having formed it a mere 

 mechanical mixture of these gases. 



If we should stop for a moment to consider 

 the enormous loss of oxygen which the atmo- 

 sphere incessantly endures, thousands of tons of 

 this gas being withdrawn from it year by year, 

 and yet that by all attainable evidence* we are 

 assured that the composition of the air has not 

 altered from age to age, the reflection comes 

 upon the mind with overwhelming force, How 

 is this loss repaired? What can be that ex- 

 haustless spring which pours back the exact 

 equivalent of these abstracted quantities into 

 our beautiful air? Had not some means of its 

 restoration been preordained, there can be no 



* The air contained in a jar, buried in the destruction of 

 Pompeii, when analysed, showed no chemical difference from 

 air analysed at the same time on the surface of the earth. 



