158 Mr. Poulett Scrope's observations on the Volcanic 



many points, the abrupt sections of these rocks, which are 

 only partially covered by a sprinkling of ashes, puzzolana, 

 pulverized slate, and other fragmentary matter. The bottom 

 of this cavity is occupied by water to about a third of its su- 

 perficial extent ; the remainder is a plain, on which the village 

 of Meerfeld is seated. 



The most southerly point of this district, on which volcanic 

 products have been met with, is the vicinity of the baths of 

 Bertrich, a village seated at the bottom of the deep and nar- 

 row mountain gorge of the river Isbach, which flows at the 

 distance of a few miles into the Moselle. 



Here a lava, which has congealed into an exceedingly hard, 

 tough, and compact basalt, full of crystals of olivin and augite, 

 appears to have been emitted from clefts in the grey wacke, on 

 three or four neighbouring points, upon the vei*y brink of 

 the steep slope, or rather precipice, which forms the northern 

 flank of the valley. Very few aeriform explosions seem to 

 have taken place, since scarcely any scoria 3 were ejected, and 

 the few that occur lie in beds upon the surface of the lava, 

 around its three principal sources, and were therefore thrown 

 up after its emission. At each of these points is a very small 

 cone. The most easterly, called the Fackerkohl, has an evi- 

 dent crater encircled by rocks of basalt covered by scoria?. 

 From hence a stream of basalt may be traced uninterruptedly 

 into the bottom of the valley, (which is here about 600 feet in 

 depth.) falling in a sort of indurated cascade over the almost 

 perpendicular cliffs of transition slate. 



The next cone, called Falkenlay, consists of a mass of ba- 

 salt covered by a deep bed of scoriae, and also gives rise to a 

 copious current of basalt, which descends into, and has usurp- 

 ed the channel of the Isbach to some distance, both up and 

 down the stream. The third point of eruption presents two 

 very low and small cones, formed entirely of scoriform basalt, 

 and appears to have produced a current of no great magnitude, 

 which may be traced at least part of the way down the nearest 

 ravine into the main valley below. 



The exceeding crispness of the scoria? of this locality, parti- 

 cularly of the Falkenlay, is remarkable. Fragments of grey- 

 wacke, greywacke slate, and quartz, partly fused, and gradu- 



