16 The Silurian System. 



Mr. Murchison begins the investigation by a description 

 of the Oolitic beds which cross England from Dorsetshire 

 to Yorkshire, forming the high districts of Oxfordshire and 

 Gloucestershire, traces the limits of these beds, and points 

 out the peculiar fossils by which the inferior part of the 

 series is distinguished. 



In a work devoted to philosophical objects, our readers 

 will hardly be prepared to expect observations of so much 

 practical importance as those which we are about to quote 

 regarding the importance of geological science in guiding 

 the operations of the practical miner, which we hope will 

 have good effect in pointing out the error of being guided 

 altogether by practical men in our investigations for coal. 

 " In the vicinity of Burley-Dam some of the beds of 

 Lias are so hard as to have induced Lord Combermere 

 to quarry them for slating purposes, and others in the 

 same vicinity being slightly bituminous have very much 

 the aspect of Kimmeridge coal. The mineralogical cha- 

 racters of this formation so closely resemble coal shale, 

 that those unacquainted with its stratigraphical position 

 and zoological contents, particularly in Oxfordshire and 

 other interior parts of the kingdom, have frequently sunk 

 into it in search of coal." And a little further on, after enu- 

 merating the list of fossils in the lower Lias, Mr. Murchison 

 observes, " it was gratifying to observe in this detached basin 

 of North Salop shells identical with certain unpublished 

 species first brought to notice by my visit to Brora, Suther- 

 landshire, the strata of which distant tract, containing a 

 sort of coal, were by means of their organic remains identi- 

 fied with similar carbonaceous strata of the Oolitic System, 

 in the eastern moorlands of Yorkshire. Had the Lias of this 

 Salopian tract contained coal as good as that found in the 

 Oolitic formations of Whitby and of Brora, it might have 

 been questionable whether in a country so distant from any 

 deposit of the old or true coal, it would have been worth 

 extraction; but no trials have brought to light any por- 



