334 Notices and Extracts from the Minutes of the Geological Society. 



of the Jura, it is more reasonable to infer that the waters which are charged 

 with that salt, have acquired it in their passage through rocks of the forma- 

 tion of Muhlingen, or others analogous to them. 



The probability in favour of this idea approaches to demonstration, from the 

 fact, tliat the above saliferous formation is the same as that from which flow 

 the thermal waters of Baden and Schinznach, both abounding in the sulphates 

 of soda and lime. Those springs are about a league distant from Muhlingen, 

 the former to the east, the latter to the west, of that place. 



A simple and natural explanation of the origin of sulphate of soda in mi- 

 neral springs is the result of the new discovery which is the subject of this 

 notice ; affording also an additional example in favour of the philosophical 

 precept of Bacon :■ — " Non fingendum, aut excogitandum, sed inveniendum 

 quid Natura ferat aut fiat." 



Charles de Gimbernat. 



Geneva, September 29th, 1825. 



4.— -Extract of a Letter from B. de Basterot, Esq. to Dr. Pitton, V.P.G.S. 



[Read Dec. 1, 1826.] 



The attention of geologists having been recently directed in a peculiar 

 manner towards the beds below the chalk, I was glad to have it in my power 

 to examine the strata in the vicinity of Folkstone, about which I had under- 

 stood there still existed some uncertainty ; and I devoted to that purpose a 

 portion of the time, during which I was detained at Dover, at the close of the 

 year 1824. 



The beds of white chalk which form the cliffs for some distance on the 

 shore between Dover and Folkstone have been so well described by Mr. 

 Phillips, that I observed there nothing which it is necessary to mention. The 

 gray chalk rises gradually from beneath the white in approaching Folk- 

 stone, and the two beds are very closely connected together ; but a sort of 

 natural separation is intimated by a copious spring which issues from the cliff 

 about the place of junction. Towards the West of this place the real escarp- 

 ment retires from the shore, and the cliffs are formed solely by subsided 

 masses of white and gray chalk, the disposition of which sufficiently indicates 

 the presence of an argillaceous stratum beneath, although the latter is no 

 where visible either on the shore above the sea, or among the ruins at the 

 foot of the real escarpment. About a mile from the town of Folkstone I 

 observed for the first time, traces of green-sand among the subsided ruins, in 



