HOW PLANTS BEGAN TO BE). 19 



hydrogen, closely locked up with one atom of 

 oxygen. It takes an amount of sunlight, which 

 we will call B, to unlock this union and separate 

 the atoms. The oxygen once more goes off free 

 into the air, and the hydrogen joins in a loose 

 union with the carbon already spoken of. Now, 

 burn the material resulting from these two acts, 

 and what happens ? Two atoms of oxygen 

 once more unite with the one atom of carbon, to 

 form a particle of carbonic acid ; one atom of 

 oxygen once more unites with the two atoms of 

 hydrogen to form a particle of water, and there 

 is given out in the act of union an amount of 

 light and heat exactly equal to the A and B 

 originally locked up in the act of separating 

 them. 



I have now made it clear, I hope, what plant 

 life really is in its final essence. In nature at 

 large, the elements which chiefly compose it— 

 namely, carbon and hydrogen — exist only in very 

 close union with oxygen ; the plant is a machine 

 for separating these elements from oxygen under 

 the influence of sunlight, and building them up 

 into fresh forms, whose great peculiarity is that 

 they possess energy or dormant motion. 



Now the animal is the exact opposite of all 

 this. He is essentially a destroyer, as the plant 

 is a builder. The plant produces ; the animal 

 consumes ; the plant makes living matter, the 

 animal breaks it down again. He is, in fact, 

 a slow fire, where plant products like grasses, 

 fruits, nuts, or grains, are consumed by degrees 

 and reduced once more to their original condition. 



The animal eats what the plant laid by. He 



