ORIGIN AND NATURE OF COAL, 85 
mencement of new successions of change and of activity. 
Set free from their long imprisonment, they return to their 
native atmosphere, from which they were absorbed by the 
primeval vegetation of the earth. To-morrow they may 
contribute to the substance of timber, in the trees of our 
existing forests; and having for a while resumed their place 
in the living vegetable kingdom, may, ere long, be applied 
a second time to the use and benefit of man. And when 
decay or fire shall once more consign them to the earth, or 
to the atmosphere, the same elements will enter on some 
further department of their perpetual ministration in the 
economy of the material world.” * 
* Ba. p. 481. 
