VITALITY 55 



and in another case in the formation of an oakc 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. 



The matter of the animal body is that of inorganic 

 nature. 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 ques- 

 tion. It is the compounding, in the organic world, of 

 forces belonging equally to the inorganic, that consti- 

 tutes the mystery and the miracle 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 inorganic to the or- 

 ganic; and such a reversal is at least conceivable. The 

 tendency, indeed, of modern science is to break down the 

 wall of partition between organic and inorganic, and to 

 reduce both to the operation of forces which are the same 

 in kind, but which are differently compounded. 



Consider the question of personal identity, in relation 

 to that of molecular form. Thirty-four years ago, Mayer 

 of Heilbronn, with that power of genius which breathes 

 large meanings into scanty facts, pointed out that the 

 blood was "the oil of the lamp of life," the combustion 

 of which sustains muscular action. The muscles are the 

 machinery by which the dynamic power of the blood is 

 brought into play. Thus the blood is consumed. But 

 the whole body, though more slowly than the blood, 

 wastes also, so that after a certain number of years it 



