BEVAN — ON THE ANTHRACITE-COAL. 



79 



111 luu pans. 



Bitu- 

 Carbon. minous 

 Matter. 



In 100 parti 



In 100 parts. 



Bitu- 



Carbon. minous 



Cyfartha, cont. — Matter. 

 Cmn-mwyn. . . . 88.87 9.00 

 Crom-y-gls .... 89.29 6.58 

 Gelly-deg .... 91.86 6.14 



Big Vein .... 82.33 13.17 



Ras-las or Bydellog . 82.79 12.96 



Yard Vein .... 80.92 16.20 



Four Foot Coal . . 80.15 15.10 



Red Coal .... 84.25 12.75 



8. Hirwain — 



Big Vein .... 88.94 7.18 

 Four Foot Coal . . 90.26 7.86 



6. Doivlais — 



Big Vein .... 85.00 11.87 



Ras-las 85.02 13.23 



Upper Four Foot . 85.75 12.75 



Cwm Cenol .... 88.63 9.74 



Little Vein. . . . 86.90 11.72 



9. Onlwyn and Neath Valley — 



10. Swansea Valley — 



Eighteen Foot Coal. 91.43 6.24 



Nine Foot Coal . . 93.12 5.22 



Big Vein .... 92.89 5.61 

 Brass Vein .... 92.46 6.04 

 Black Vein .... 93.14 5.36 



7. Cyfartha — 



Big Vein .... 90.28 7.97 



Cwm-ddu .... 88.78 9.22 



The next point is rather a quoestio vexata, viz. the causes which have 

 produced anthracite. Many geologists consider the causes to be 

 purely chemical, and that they are in action at the present time, — 

 causes involving the existence of an immense internal heat, which is 

 gradually changing the whole basin. Dr. Schafhaeutl considered that 

 the anthracite was altogether a distinct and separate formation ; that 

 it never was bituminous, but that it derived its distinctive features 

 from a different chemical composition of the original vegetable 

 matter. I cannot myself agree with either of these theories ; nor do 

 I consider that the cause of the change was chemical, or that it is 

 still in progress. With the second hypothesis I still less agree ; for 

 under the seams of anthracite-coal we find the same underclays as 

 underlie the bituminous seams, proving, at all events, that the same 

 conditions of soil and growth existed in one as the other ; added to 

 which, I have frequently found in the anthracite fossil plants identical 

 with those of the bituminous coal, the only difference being that the 

 former appear to have been subjected to greater heat. 



The facts,, too, which I have stated about the gradual commencement 

 at Rhymney, and the subsequent increase of the anthracitic condition, 

 do not seem to be compatible with the totally distinct chemical opera- 

 tions. It is generally stated that the proximity of trap-rocks, <fec. is 

 a common cause of the change to anthracite. In the South Wales 

 basin there are no visible trap-rocks (except in Pembrokeshire, where 

 they have nothing to do with the present question), but, nevertheless, 

 I cannot help imagining that the changes have been caused by trap- 



