S()2 Scientific NoticeS'^Chmistry. [A'piiii^ 



basalt, upon which they rest. The basalt finally disappears 

 south-east of Darmstadt, and is succeeded by primitive rocks. 

 There are strong salt-springs at Soden, and various mineral 

 waters near Frankfort and Hadnigstein. 



The Falkenstein mountain, though composed of talc-slate, 

 protrudes through the high table land in the form of basalt. To 

 the north of this the older rocks disappear, and the district is 

 occupied by grauwacke. The grauwacke is divided intoquartzy 

 grauwacke and grauwacke slate ; the latter is very distinct from 

 micaceous slate, and contains casts of Spiriferi, of the Pleuro- 

 branchi of Cuvier, &c. ; the former offers encrinites, and unknown 

 coralloids. The valley of the Lahn, between Coblentz and 

 Diety, affords the best sections of grauwacke, and higher up that 

 river the transition limestone appears at Baldowinstein. The 

 schalstein (or problematic stone of Von Buch) is seen in all its 

 varieties in the valley of the Aar, and with it are associated por- 

 phyry, carbonate of hme in veins, iron, and copper. At Diety 

 and Baldowinstein, porphyry seems to rise through the lime- 

 stone. Crystalline dolomite, resting upon transition limestone, 

 is the most recent formation observable in the mountainous 

 ranges of Nassau. No diluvial detritus is seen in any part of 

 the duchy, but quartz pebbles in sand occur in the elevated 

 plain between Selters and Nassau : these are supposed to have 

 been torn from the grauwacke by local causes, and to have been 

 deposited prior to the elevation of that formation. The author, 

 reflecting upon the marine fossils on the summits of some of 

 these mountains, infers, that the horizontal strata were formed 

 at the bottom of a sea, and were subsequently elevated ; and he 

 is inclined to attribute the origin of the grauwacke to the attri- 

 tion of the primitive rocks during the period of their elevation. 



E.W.B. 



Article XIII. 



SCIENTIFIC NOTICES. 



Chemistry. 

 1 . Vegetable Principle in Saponaria Officinalis. 

 We are informed that Dr. Osborne of this city has detected a 

 principle in the Saponaria oflicinaUs, or Soap-wort, which in 

 some of its characters more nearly resembles picrotoxia than any 

 other proximate vegetable principle hitherto described, but is 

 sufficiently distinguished from it in others. It was obtained 

 from the decoction. It has an extremely bitter taste, is of a 

 whitish colour, and crystallizes in prisms, both radiated and 

 plumose. On the application of a low heat it fuses ; and when 

 the heat is increased, swells and blackens. It possesses neither 



