Geological Sketch of the Thuringerwald. Bi/ 

 M. de HoFF, Counsellor of Legation at 

 Gotha. 



' (Extracted from M. Leonhard's Annuaire Mineralogique, by M. de 



'- Bonnard, Engineer in Chief of the Mines.) 



no 



(Annales des Mines for 1817.) 



M. de HoFF has published a descriplioiij in two volumes, 

 of the Thuringerwald, a small chain of mountains, having a 

 direction from N.W. to S.E. and separating Franconia from 

 the Duchies of Saxony, the whole of which is also knowu 

 under the ancient name of Thuringia. The geological part 

 of this work has been extracted in M. Leonhard's Annuaire 

 Mineralogique for 1815; of that extract we are about to 

 give the substance. "We shall also extract some notices: 

 1st, of a memoir by the same author on the secondary lime- 

 stone of the northern side of the Thuringerwald, inserted in 

 the Annuaire Mineralogique of 1810 ; 2dly, of a letter from 

 M. de Hoff to M. Leonhard, inserted in the same work for 

 1811, page 375, &c. 



The most elevated parts of the Thuringerwald are formed 

 of granite, porphyry, and slate ; the granite principally forms 

 the western extremity and all the southern slope from the 

 crest. It sometimes rises as high as the summit, and appears 

 here and there on the northern slope, or on the Thuringian 



