Natural Theology. 



chemists named it vital air. No animal can live with- 

 out it. It not only enters into the tissues, forming 

 in the higher animals bone, and muscle, and nerve, 

 but it is also the great purifier of the animal system, 

 combining with the worn-out particles, giving them 

 the form best fitted for elimination from the body. 

 And by this very process, it gives that power to the 

 system which volition calls into play in every move- 

 ment of the body, and exercise of mind ; and as it 

 burns up the organic compounds, it becomes the 

 greatest agent in securing in the body that degree 

 of warmth which the functions of life demand. 



It is also the producer of artificial light and heat 

 in all ordinary combustion. Practically, artificial 

 light and heat would be impossible without just 

 such an element as oxygen is. We have indeed 

 light and heat from the combination of other ele- 

 ments, but their products are generally solids or 

 noxious compounds. It may be said that hydrogen 

 and carbon, the other elements concerned in ordi- 

 nary combustion, show as much design as oxygen ; 

 and so undoubtedly they do. They were created in 

 reference to each other ; and the office of each, and 

 the perfect adaptation of each one for that office, we 

 shall endeavor to show in another place. But all 

 will agree that oxygen is the great heat and light 

 producer. In vain were our coal-beds formed, or the 

 veins of the earth filled with oil, were it not for the 

 free oxygen of the air. For without this, they could 

 give no more light and heat than the granite of the 

 mountains, or the waters that gush from their sides. 



