IS LIFE UNIVEKSAL? 131 



The leaves, under the stimulus of the sun's rays, 

 decompose carbonic acid, giving off part of the 

 oxygen, and " fix," as it is said, the carbon in union 

 with hydrogen, and sometimes with nitrogen, &c., to 

 form the various vegetable cells and their contents. 

 It is curious that the oxygen and hydrogen, thus 

 united with the carbon, are very often in the same 

 proportion in which they unite to form water. Starch 

 and sugar, for example, both consist of carbon and 

 (the elements of) water. 



An animal now consumes this plant. In digestion 

 there takes place again a precisely similar process to 

 that with which we started the germination of the 

 seed. The substance of the plant partially decom- 

 poses ; a portion of it sinks into a state approximating 

 to the inorganic, while another portion (doubtless, by 

 means of the force thus generated) becomes more 

 highly vitalized, and fitted to form part of the animal 

 structure. The germination of the seed, and animal 

 digestion, are parallel processes. Each of them is 

 twofold a decomposing and a vitalizing action going 

 on together, the latter having its origin in and de- 

 pending upon the former. 



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