THE BEGINNINGS OF LIFE 



which must have attended the origin of living 

 aggregations of matter. By following out this 

 method new light will no doubt eventually be 

 thrown upon the past history of our planet, and 

 a sound basis will be obtained for conjectures re- 

 garding the existence of living organisms upon 

 some of our neighbour worlds. 



In this account of the matter we have com- 

 pleted, so far as is needful for the purposes of this 

 work, our exposition of the evolution of the earth. 

 Combining the results obtained in the three fore- 

 going chapters, we may contemplate in a single 

 view the wonderful advance in determinate multi- 

 formity which has resulted from the integration 

 of the earth's matter, with the accompanying dis- 

 sipation of its internal motion. We have wit- 

 nessed this process of evolution as manifested in 

 geologic and meterologic phenomena ; we have 

 followed the wondrous differentiations and inte- 

 grations of the molecular motion which the cool- 

 ing and consolidating earth has received from 

 the centre of our system, — and finally, from 

 that very cooling and consolidation upon which 

 all the foregoing phenomena are dependent, 

 we have shown that there must naturally have 

 ensued a progressive chemical heterogeneity, re- 

 sulting at last in the genesis of compounds 

 manifesting those properties which we distin- 

 guish as vital. Thus the continuity in cosmic 

 evolution is grandly exhibited, and we see more 

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