CIRCULATION OF MATTER. 



433 



CHAPTER III. 



CIRCULATION OF MATTER. 



1070. The relations of the three king- 



What proves ,.."*' . , . 



the relation doms of nature have been already mciden- 



tall y considered in former parts of this 

 nature? work. It remains to present the subject 



in a single view. It is obvious, at a glance, that the soil 

 does not furnish all the material which is required for the 

 wants of vegetable life. The level of our meadows 

 is not lowered by removal of successive crops, nor 

 does the forest dig its own grave at its roots as it lifts 

 its ponderous trunks into the air. The atmosphere, 

 as well as the soil, contributes to the increase of mass, 

 whether of wood or grain, and indirectly feeds all 

 races of animal existence. The relation of the three 

 kingdoms of nature is thus established. 



1071. Water is one of the principal 



How does wa- . 



ter serve in agents in the system of circulation of 

 a/matte?/ matter > which constitutes the life of the 

 globe we inhabit. In the fulfillment of its 

 office, it passes incessantly from sky to earth, now 

 mingling with the currents of the atmosphere, and 

 anon with those which form the arteries and veins 

 of the great world of waters. Lifted into the atmos- 



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