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 dif- 

 ficult 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 

 oxygen 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 towards 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 

 motion displayed in its descent, but the form of the 

 motion depends on the character of the machinery 

 interposed in the path of the water. In a similar way, 

 the primary action of the sun's rays is qualified by the 

 atoms and molecules among which their energy is dis- 

 tributed. 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 oxy- 

 gen, the molecular machinery through which the com- 

 bining energy acts may, in one case, weave the texture 

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

 of a man. 



