116 DR. REDFERN, ON THE TORBANEHILL 



of coal " are totally different, but both agreeing with cor- 

 responding sections of wood." 



First, the Torbanehill coal shows " no difference in struc- 

 ture whichever way the section is made." My conclusion is 

 exactly the reverse: — That there is always a remarkable dif- 

 ference in horizontal and vertical sections of Torbanehill coal ; 

 and to this I add, that that difference is of the same kind as 

 the difference which exists between horizontal and vertical 

 sections of other coals. 



In evidence of the correctness of my observation I refer, 

 1st, to the illustrations accompanying this paper ; 2nd, to 

 confirmatoi'y photographic representations of different sections 

 which I exhibited at the last meeting of the British Associa- 

 tion ; 3i-d, to all horizontal and vertical sections prepared in 

 the way I have directed, as they all show a very marked 

 difference even to the naked eye ; and, 4thly, to the fact that 

 the Torbanehill coal will only split in one direction ; in it- 

 self furnishing undeniable evidence of there being some 

 difference in the arrangement of the structure in different 

 directions. 



Second, a cubical fragment of coal " on four of its six sides, 

 in certain lights, will exhibit a fibrous appearance, like a 

 longitudinal section of wood ;" and " transverse and longitu- 

 dinal sections" of coal " are totally different, but both agreeing 

 with corresponding sections of wood." My conclusion is, that 

 a cubical fragment of coal on four of its six sides exhibits a 

 striated appearance altogether unlike that presented by a 

 cubical fragment of wood, and produced by the laminar 

 aggregation of the structures of the coal. To support my 

 conclusion, I simply draw attention to the fact, that if I cut 

 a piece of wood across the direction of the striae on one of its 

 surfaces I see a number of rings, which are the cut ends of 

 the woody fibres and vessels ; but if I cut a piece of coal in 

 the same way, I only find other striae produced by its laminae, 

 as if 1 were to cut in various directions across the leaves of a 

 book. Again, it is stated " that transverse and longitudinal 

 sections" of coal " are totally different, but both agreeing 

 with corresponding sections of wood." I conclude that, 

 though horizontal and vertical sections of coal differ, both are 

 also entirely and essentially different from corresponding sec- 

 tions of wood ; for, whilst all vertical sections of coal present 

 the same horizontally-striated appearance, corresponding sec- 

 tions of wood present striae arranged vertically. If we cut 

 across the striae of wood we see the ends of its fibres and 

 vessels ; but when sections are made across the direction of 

 the stri2e of coal, other striae appear ; for the simple reason 



