MurcMson s Silurian System. 17 



tion of combustible matter, whether termed lignite or im- 

 pure coal, worthy of the name of a bed. To convince the 

 resident gentry and speculators of northern Salop who are not 

 aware of the value of the evidence afforded by organic re- 

 mains, of the hopelessness of their search after coal, I beg to 

 repeat, that the black shale is underlaid by the saliferous 

 marls of the New Red Sandstone. In addition to the instances 

 already given, I may state, that the sinkings of Sir Corbet 

 Corbet at Adderley, opposite Kent's Rough, and near 

 the northern edge of the basin, proved this fact ; for 

 upon piercing the black shale to the depth of 300 feet, a 

 brine spring was reached ! Lastly, an examination of the 

 annexed wood cut* and the map will show, that the basin 

 not only rests upon marls and other strata of the New Red 

 System, but is surrounded by them ; and a reference to 

 the general tabular view attached to this work will prove 

 that the whole of the enormously thick system of new red 

 sandstone (as fully expanded here as in any part of England) 

 lies between the black shale and the true coal measures. If 

 coal really passes beneath any portion of this country, it 

 ought to be first sought for at points nearer to Oswestry, 

 Wrexham, Shrewsbury, Wellington, Newport, and Madeley 

 in Staffordshire ; in short, towards the out crop of the coal 

 measures which rise nearly on all sides from beneath the 

 new red sandstone. Now as this tract lies in the centre of 

 the circle above mentioned, it is necessarily the very spot in 

 the whole area where the search for coal is most hope- 

 less, being that were the overlying deposits are thickest." 

 25. — On another occasion Mr. Murchison observes, that 

 he had learnt that sinkings for coal had been carried 

 on for some extent between Whitchurch and Market Dray- 

 ton; but on examining the district, he soon found that 

 the black shale supposed by the inhabitants to be coal- 

 shale, was nothing more than Lias, as was proved by an 

 abundance of fossils, and separated from the coal measures 



* We regret we have not the means of introducing this cut. 



