1825.] Mr. Webster's Reply to Dr. Fittvn. 4a 



and the calcareous rocky bed below tliis the green sand, the 

 latter bed resembling, indeed, in many particulars, the rock of 

 the Underclitl', Isle of Wight. It happens that tlie bed ofRei- 

 gate stone, which continues its course eastwards past Godstone, 

 appears not to reach to Maidstone, and is actually uanting at 

 Folkstone, at least in the i'orni of firestone : thus the chalk or 

 chalk marl is divided from the hard rock of Folkstone only by a 

 bed of blue marl; and since the true chalk marl is itself iVe- 

 quently grey, and as the liard rock below the blue marl resem- 

 bles some of the states of the original green sand, it is not at 

 all surprising that this error should have been fallen into. We 

 have no method of determining upon the identity of beds in. 

 places distant from each other, but by the correspondence in. 

 their nature and their order of superposition : there appeared, 

 therefore, considerable reasons for determining the Folkstone 

 rock to be the g/'tT// sand. This being supposed to be estab- 

 lished, it followed necessarily, that although the rest of this 

 latter range, from Coxheath all round the weald, varied almost 

 entirely m its character, so as to be 'd.J'errttgi)ioi(s sand (mine- 

 ralogically) ; yet (since according to the principles of geognostic 

 nomenclature, beds do not change their names in different 

 places according to the qualities of the substances forming them,) 

 the whole bed acquired (he name of nvif?,' ^aiid which had thus; 

 been given to a part. This is my view of the way in which I 

 conceive so good an observer as iMr. Conybeare mioht have 

 been led to give to a stratum a name whicii did not properly 

 belong to it. I have thus stated frankly my opinion on this 

 subject; and it will remain for him to say how far 1 am rights 

 It is, I am aware, putting his candour to a severe test; but ia 

 that I have the fullest coniidence. 



I must now return to Dr. Fittun. In p. 36G, line 12, he 

 observes, that Mr. (Jouybeare " adopted my arrangement of the 

 strata of the Isle of Wight, and regarded the lower part of that 

 island as composed oi one sciies oiili/ of ferruginous t^.and v.hich 

 he identities with those of Haslings." He then proceeds to 

 show, in p. o07, that there are two distinct series of sands below 

 what I have called green sand, which are separated from each 

 other by a stratum of clay. In this passage I am under the ne- 

 cessity of pointing out a double oversight ; for, in the lirst place, 

 he must have been aware that I had two ierruginous sands in my 

 arraiigenumt, since he actually states it in hi.^ table, p. 3(i9. In 

 the second place, he might have seen that Mr. ('o)iybeare does 

 not adopt my arranaemenl, but distinctly confines /mfeiriiginons 

 sand to my lon-er one oulij. 



Dr. Fitton has also stated, erroneously, that I mention the 

 Purbeck beds as existing in the Isle ofVv'ight. Since 1 had 

 never expressed this decidedly, and as I had long known that 

 they are not to be found there (having several years ago exa-' 



