SECTION C.—GEOLOGY. 
SOME GEOLOGICAL ASPECTS OF 
RECENT RESEARCH ON COAL 
ADDRESS BY 
PROF. H. G. A. HICKLING, 
PRESIDENT OF THE SECTION. 
TRADITION almost demands that a Sectional President shall embark on 
that salutary though often painful process known in the outer world as 
stocktaking ; and in my own case the historic succession seems to point 
with no uncertain finger to the department of the geological store where 
the accounting is to be done. My predecessor at Leicester led us to the 
Carboniferous rocks ; at Aberdeen we reviewed the investigation of the 
plants which they contain ; and so it falls to my lot at this meeting to 
take stock of our knowledge of the rock which the plants themselves 
have formed. 
I shall attempt this the more willingly because I believe that this rock 
is not only in itself worthy of more attention at the hands of the geologist 
than it has been generally accorded, but is likely to repay that attention 
by shedding light on some of the major problems of the science. Later 
in the address I shall revert to the conception of coal as a metamorphic 
rock. ‘The idea is ancient, but the data necessary for its establishment 
and more precise definition have been lacking. Perhaps they are now to 
hand. If that be so, we have in this familiar rock an indicator of crustal 
conditions far more delicate than any of the index minerals of the meta- 
morphic petrologist ; so delicate indeed, that should it come within range 
of even the lowest grade of metamorphism, as usually understood, it is 
completely shrivelled up and leaves only a trace of graphite as witness of 
its former self. 
But before this aspect of the matter can be seriously discussed, it is 
necessary to know the nature of the rock itself; or, rather, rocks, since 
there are many kinds of coal. And this is where our knowledge has been 
most deficient. Any text-book will furnish a body of more or less con- 
vincing circumstantial evidence concerning the conditions under which 
certain deposits of coal have been formed. It may discuss at length 
the question whether the deposits have been formed by the growth of 
vegetation im situ or out of ‘ drifted’ plant material; but as to the rock 
itself, the most we are likely to learn is that it contains recognisable 
fragments of plant tissue and, frequently, plant-spores. As to the nature 
and condition of the general mass of the rock, we shall probably learn 
nothing. 
