THE PATH OF EVOLUTION 



by appropriate means, made to assume many forms, 

 such as physical motion or the generation of electricity, 

 etc. ; but whatever form it might assume, its origin was 

 the same. The carbon and hydrogen, dissociated 

 from their earlier combinations by the solar energy 

 transmitted through the Ether, had been stored up 

 as cellulose in the living plant, and afterwards, when 

 excluded from atmospheric oxygen, remained as 

 woody tissue or was changed into mineral coal. Heat 

 thus became the form of energy in which the dead 

 tissues of the once living plant were now available. 

 It was different when the plant was living. An 

 example of its mode of action then, may be taken 

 from a contrivance in mechanics. 



It often happens that it is desirable to raise to the 

 top of a hill a part of the water that in a brook runs 

 to waste at the foot thereof. This is conveniently 

 done by causing a portion of the water to flow in a 

 large tube for some distance down the declivity of the 

 brook, the water escaping through a valve at the end. 

 Just above this valve is another valve opening into 

 a closed air chamber, to which is attached a small 

 tube leading to the top of the hill. In operation the 

 water flows down through the large tube and valve 

 until the friction caused by its rapid flow raises and 

 suddenly closes the exit valve. The momentum of 

 the column of water, being instantaneously checked, 



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