Mr. Bakewell's Lectures. 427 



or rather the account of them that you have published, 

 permit me to mention, that I still with additional reason, 

 as I conceive, arlhere to my former position, in the Derby 

 Report, &c. with respect to the metalo-basaltic Limestone 

 Rocks of Derbyshire, having lower places in the series than 

 any other Rocks that I have seen, or know by the Reports 

 of others, in the British Islands; and still conclude, as 

 I mentioned in your 102d page (vol. xxxix.), that the same 

 do not appear in the north-west of Yorkshire, in particular, 

 as Mr. Bakewell is made to assert, p. 236 ; since on inquiry, 

 I am told, that his reasons for so saying are, that " the 

 quality of the Limestone and the Mineral Veins are the 

 same," which I hold to be very inadequate marks of the 

 identity of strata: surely Mr. B. might have done, or can 

 now tell us, whether the succession upwards, from what 

 he calls the 4th Limestone, is the same, or at all allied, 

 to that I have described in Derbyshire ? but above all, 

 whether he was able to detect, all or any considerable pro- 

 portion of the species of shells and other Reliquia in the 

 Yorkshire Limestones, that the late Mr. William Martin 

 has figured and described in his " Petrificata Derbiensia" ? 

 Shropshire or North Wales, I have not seen, except in the 

 distant horizon, but from what I have read of Mr. Arthur 

 Aikin's on those districts, and learnt from my valuable 

 friend Mr. John Lloyd, of Wygfair, {who descended into 

 Elden Hole, many years ago,) and others, I conclude the 

 limestone Rocks there, to be the same with that which un- 

 derlies the great South Wales Coal-bason, of which I have 

 made mention in the preface to my Report, p. xiii, and 

 which overlies a Red-Marl series, such as I have described 

 at p. 270, in your 39th volume, but not the same pro- 

 bably. 



That the Caverns in Limestone Rocks, were not generally 

 formed by the washing of subterranean currents, at least, 

 are not now enlarging or deepening by that means (as I 

 hear that Mr. B. maintains respecting certain Caves in or 

 near Cumberland), must be abundantly evident, to those 

 who will examine the bottoms of such Derbyshire caverns 

 or opens, as are connected together, and which will he 

 found in great part filled up with mud, sand, shale-grit and 

 quartz gravel, &c., washed into them from the surface of 

 the shale, by means ot some o\ the Water-swallows that 

 I have mentioned, Rtp. i, p. 2L)5 : Merlin's Cave, in the 

 Land occupied bv the late William Langsdon, Esq. (but as 

 1 am told, not belonging to him, as I have staled) and now 

 Ec 2 by 



