VITALITY. 49 



these different names must not mislead us regarding 

 the qualitative identity of the two forces. They are 

 both attractions; and, to the intellect, the falling of 

 carbon atoms against oxygen atoms is not more diffi- 

 cult of conception than the falling of water to the 

 earth. 



The building up of the vegetable, then, is effected 

 by the sun, through the reduction of chemical com- 

 pounds. The phenomena of animal life are more or 

 less complicated reversals of these processes of reduc- 

 tion. We eat the vegetable, and we breathe the oxy- 

 gen of the air; and in our bodies the oxygen, which 

 had been lifted from the carbon and hydrogen by the 

 action of the sun, again falls toward them, producing 

 animal heat and developing animal forms. Through 

 the most complicated phenomena of vitality this law 

 runs: the vegetable is produced while a weight rises, 

 the animal is produced while a weight falls. But the 

 question is not exhausted here. The water employed 

 in our first illustration generates all the motiou dis- 

 played in its descent, but the form of the motion de- 

 pends on the character of the machinery interposed 

 in the path of the water. In a similar way, the pri- 

 mary action of the sun's rays is qualified by the atoms 

 and molecules among which their energy is distributed. 

 Molecular forces determine the form which the solar 

 energy will assume. In the separation of the carbon 

 and oxygen this energy may be so conditioned as to 

 result in one case in the formation of a cabbage, and in 

 another case in the formation of an oak. So also, as 

 regards the reunion of the carbon and the oxygen, the 

 molecular machinery through which the combining 

 energy acts may, in one case, weave the texture of a 

 frog, while in another it may weave the texture of a 

 man. 



