17 



volume, have produced its ultimate entire solidification, at 

 a much earlier period — and the probable acceleration of its 

 mean motion within the period of human observation. 



Whether the giving off of heat and the consequent re- 

 duction of temperature and volume produces condensation, 

 or whether the slower succeeding combinations of chemical 

 affinity and finally of organic life tending to solidification, 

 results in a reduction of temperature is a complex and diffi- 

 cult question beyond the range of the present subject — the 

 existing temperature and conditions are matters of fact. 



The atmosphere, the waters, organic life, the solidifying 

 and solid crust of the earth are for the most part composed 

 of the same elements of matter. To acquire any definite 

 idea of the transformations of terrestrial matter that have 

 resulted in the solidification of a vast amount of native 

 gaseous elements, through their chemical liquefaction and 

 subsequent consolidation, since the creation of living or- 

 ganisms upon this sphere — the results of research in several 

 branches of science must be briefly collated, for these lose 

 their distinctiveness, and seem to converge as we draw 

 nearer and nearer the truth in investigating nature. 



III. 



Chemical and Geological Changes. 



There are only thirteen (13) of the sixty-five (65) ele- 

 ments, still supposed to be simple, that make up the great 

 bulk of terrestrial matter. Of these, only four (4) that are 

 really important in this connection. These are the organic 

 elements, oxygen, hydrogen, nitrogen, and the non-metallic 

 solid, carbon. 



Oxygen and nitrogen form the earth's atmosphere. 



Oxygen and carbon^ the carbonic acid gas mingled with it. 



Oxygen and hydrogen^ the invisible moisture, aqueous 

 vapor, and all the water in and upon the crust of the 

 earth. 8 



