and on the Transmutation of Llms to S'dex. 39 



instances are here to be met with, covered by pieces of the 

 upper measures, sometimes ahnost detached from the mass 

 oi such covering: strata. 



Although 1 differ from Mr. VVhitehurst as to the fissure 

 under the face of the High Tor, and as to valleys being ge- 

 nerally so broken; yet J doubt not but this county furnishes 

 numerous ins-tances of valleys so broken, in places where 

 the plane of the strata takes a new direction or dip, as Mr. 

 W. supposed them to do on each side of the Tor (H) in his 

 section. — The front of the High Tor is in the range of the 

 Seven rakes Minej and almost the whole of the perpendi- 

 cular roclcs therein arc covered with spar, and other matters 

 peculiar to the skirts of veins, or are of the nature of riders, 

 which I find, not to consist of fragments of the adjoin- 

 ing rocks, as most authors liave described them to be, but 

 confusedly crystallized masses, occupying and filling the 

 cavities left between the skirtings of spar and ore, which 

 the sides of the vein had in the wider parts thereof pre- 

 viously received. A large portion of all the lime-stone 

 cliffs which I have examined in this county, seem to 

 owe their origin to rake-vcins running parallel to their 

 fices, and to have had their perpendicular facades pre* 

 served to the present lime, by the facing of vein-stuff and 

 rider, with which they are coated. 



Allow me, sir, the liberty here to notice the opinions of 

 Mr. Hume, ou the identity of silex and oxygen, which I 

 have read in the 29th and 30th volumes of your useful 

 work, for the purpose of mentioning, that however far his 

 doctrines may be repugnant to those, which chemists are at 

 present disposed to treat as orthodox, yet that such must, I 

 think, have to prepare themselves for still greater innova- 

 tions, on their lists of supposed elementary substances, when 

 the operations of Nature in her grand laboratory, wherein 

 the strata of the earth were formed, and were, by their mu- 

 tual action, reduced to their present state, come to be more 

 closely and minutely examined. 



The transmutation either of lime into silex, or silex info 

 lime, can, I think, be doubted by no one, who will atttn- 

 livcly examine and consider the surface, of cither of tho 



C 4 four 



