VITALITY. 413 



reversals of these processes of reduction. We eat the vege- 

 table, 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 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 ques- 

 tion 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 charac- 

 ter 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 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 mo- 

 lecular 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. 



The matter of the animal body is that of inorganic Na- 

 ture. There is no substance in the animal tissues which is 

 not primarily derived from the rocks, the water, and the 

 air. Are the forces of organic matter, then, different in 

 kind from those of inorganic matter ? The philosophy of 

 the present day negatives the question. It is the com- 

 pounding in the organic world of forces belonging equally 

 to the inorganic that constitutes the mystery and the mir- 

 acle of vitality. Every portion of every animal body may 

 be reduced to purely inorganic matter. A perfect reversal 

 of this process of reduction would carry us from the inor- 

 ganic to the organic ; and such a reversal is at least con- 



