and their Ccmnexion with Volcanos. 61i 



ping away in all directions from the centre towards the circum- 

 ference. Several valleys in Westphalia exhibit this remarkable 

 structure, but none more strikingly than that in which the cold 

 chalybeate of Pyrmont is situated. In this instance the rocks 

 are composed of the variegated sandstone, the muschelkalk lime- 

 stone, and the keuper, which are seen overlapping each other in 

 the hills bounding the valley, but dipping in opposite directions 

 on opposite sides of it, so as to present every where escarp- 

 ments fronting each other. From the bottom of the valley, car- 

 bonic acid is constantly issuing in large quantities, impregnating 

 the springs of water, and accumulating in dry pits and caverns. 

 The valley of Dryburg, and other spots in the same country, 

 noted for the occurrence of cold carbonated springs, exhibit a 

 similar conformation of their strata. (Vide PI. III. Fig. 3.) 



Professor Buckland, in his Memoir on Valleys of Elevation, 

 published in the Transactions of the Geological Society*, had 

 previously pointed out the occurrence of such valleys in this 

 country ; and it is remarkable, that the most important of our 

 chalybeates, that of Tunbridge, is found in this kind of situa- 

 tion. Now, the relative position of the strata in these valleys 

 just as obviously suggests the idea of their having been affected 

 by some convulsion of nature, as the highly inclined rocks of al- 

 pine countries ; and it is impossible to conceive, either that they 

 could have been deposited in the first instance at so high an 

 angle, and with such a variety of dip, or that there should have 

 been such a coincidence between the elevation of their escarp- 

 ments on the opposite sides of the valley, if the beds had not 

 been once in continuity. This inference is further corroborated 

 by observing that carbonated springs are the common, and per- 

 haps the almost universal, concomitant of volcanos, especially of 

 those called extinct. Thus, they abound near Bonn and Cob- 

 lentz among the extinct volcanos of the Rhenish provinces, and 

 in the mountains of Nassau contiguous. The same country, 

 too, it has been observed, which throws out hot springs at a low 

 level, or at a point more contiguous to the supposed focus of the 

 volcanic action, affords cold carbonated ones at a higher level, 

 or at a point more remote. Thus the hot springs of Ems and 



• Vol. ii. New Series.. 



