284 The true Nature of Sand-stones and Gov glomer ales. 



ham, by Biustleton, Ferrv-hill, Coxhoe, Pittington^ Painshar, 

 Hilton, West Bovvden and South Shields, and thence by North 

 Shields, to Whitcbum in Northumberland. 



I have observed, that upon the buif or lower magnesian Lime- 

 stoneRock, a middle Red Marl, of considerable thickness, occurs 

 through this extensive line of Country. On this, the upper or 

 hght straw-coloured free Limestone occurs : and then the upper 

 Red Marl *, perhaps imbedding towards its lower part, the very 

 irregularly coarse and irregularly stratified sandstone of Sher- 

 wood Forest?, &c.: — in short, much remains yet to be known, 

 before Dr. G. can safely j-roceed in his favourite course, of sy- 

 steuiizing; before which, he will I doubt not see the foilv, of 

 dubbing our Strata with gcognostic names and distinctions : — 

 every Country nmst work out its own Geology, and not import 

 it, read made. 



Wl-.ere is NessP, mentioned p. 188, and where has Dr. Kidd 

 spoken of this place ?. 



In the rote at foot of p. 183, Dr. Kidd is rather severely chid 

 by Dr. G., for not ascribing to Mr. Jameson the whole merit, of 

 correcting the former absurd notions and theories (they made 

 part of the Geogiiosy, seeWern. Trans, i. 290), Avhich ascribed 

 all the grams of silex composing sandstones, to the meclianical 

 abrasion oi former Rocks, and the same, witli respect to the se- 

 parate masses composing covglomtraie Rocks : if he will turn 

 to p. 179 of my Report, and p. 253 of your xlivth volume, he 

 may perhaps perceive, that something more than justice has 

 l)een contended for, in tliis case, in behalf of his friend Mr. Jame- 

 son. When I was in Sutherland, in August 1812, and had 

 perfectly satisfied myself from very repeated and minute inspection 

 of the conglomerate Rock there, of its true nature, I had oppor- 

 tunities of conversing with Sir Humphrv Davy on the subject, 

 and finding him most decided in the prevailing notions, as to 

 the origin or mode of formation of these Rocks, and seeing that 

 he daily passed by them, in his anghng Excuisious, I pressingly 

 invited him to devote an hour, to examining with me, the newly , 

 expostd faces, wliich the blocks that had been recently cleaved, 

 and quarries w'liich had been opened, bv thci parliamentary Road- 

 makers, in this conglomerate Rock, so readily and numerously 

 presented for our inspection : but this he declined, and even ri- 

 diculed the idea and proposal, before the companv we were in ! : 

 this however did not discourage me, from pretty fully stating my 

 observations and conclusions on this head, to Mr. Jameson, on 

 my return through Edinburgh. Mr, J. with great candour heard 

 and replied to my statements ; and whence I conclude, that at 



*" See my recent enumeration of tlie chief British Strata, at the end of 

 Mr. Sowcrby's 1st volume of" Mineral Coiichology," No. 19. 



that 



