1823.] Rothetodtliegende and Weissliegende. 331 



science ; and correct approximations can only be produced by 

 close comparisons, and a careful attention to those details that 

 are but too often overlooked. 



Mr. Conybeare has promised to produce detailed quotations 

 from Lehman, Karsten, Von Buch, Von Humboldt, Freiesleben, 



. Von Raumer, D'Aubuisson, and Keferstein (I place these names 

 nearly in chronological order), all of which shall concur in prov- 

 ing, that the great mass of the rothetodtliegende occupies a posi- 

 tion superior to the coal measures. Now, supposing even that 

 this were the case, it could be of no avail to the argument of 

 my opponent, as rothetodtliegende does not signify the new 

 conglomerate. It is doubtless owing to such a prepossession in 

 the mind of that gentleman, that he has ventured to assert that 

 the whole of the rothliegende (with its beds of limestone and 

 porphyry), extending from the Hartz to the Petersberge on the 

 Banks of the Saale, is in a position superior to the coal forma- 

 tion. I must, however, take the liberty of observing, that this 

 statement appears wholly unjustified, being an inversion of the 



fact, and decidedly at variance with the detailed descriptions 

 and general scope of Freiesleben's work. 



My opponent seems to have been misled, and to have adopted 

 this notion, partly by misconceiving the true import of a term, 

 and partly by taking an imperfect view of the series connected 

 with the coal in the Ihlefeld, Opperode, and Petersberge districts. 

 In the first of these, which ranges to the south-east past Neu- 

 stadt, the constituent members appear (so far as they are 

 exposed) arranged in the following ascending order :* 



1. Coarse grained rothliegende, becoming gradually finer. 



2. Fine grained rothliegende. 



3. Common indurated clay. 



4. Floor shale. 



5. Coal, divided by intervening shale into three layers, 10, 8, 

 and 6 inches thick respectively, forming altogether a seam 30 

 inches thick. 



6. Roof shale. 



The roof shale and floor shale, as well as that which divides 

 the coal seam, contain impressions of ferns and reeds. 



7. Thin slaty indurated clay. 



8. Trap, for a short distance, which is partly amygdaloidal. 



9. Porphyry, extensively, in abrupt cliffs, and in mountain 

 masses. 



10. Rothliegende. 



The real purport of the term rothliegende in this series has 

 been already explained ; and I need here only add, that the 

 group (being succeeded by the weissliegende or new conglome- 

 rate, and the cupriferous marl shale), gradually thins off to the 

 eastward, until in the district of Questenberg, the weissliegende 



• See Freiesleben, vol. iv, p. 175 — 178, and also p. 146, 147; likewise vol. i. 

 p. 43, 44. 



