]40 DOMAIN I, SIDEROUS. 



contains fragments of porphyry, and also veins of 

 iron-stone, and manganese, and strata of coal, with 

 impressions of reeds, rushes, and other 'plants, 

 Lasius, 249 and 280. The red colour is evidently 

 from iron. 



" The semiprotolite of Wartburg, near Eisenach, 

 contains rounded lumps of granite and schistose 

 mica : substances found in the neighbouring moun- 

 tains. The semiprotolite of Goldlauter consists 

 entirely of porphyry, as do the primeval moun- 

 tains of that district. That of Kiffhauserberg, in 

 Thuringia, contains rounded argillites from the 

 neighbouring mountains of the Hartz. Petrified 

 wood is found in this last, Voigt's Letters, 19, 

 20. According to Voigt, the semiprotolite found 

 under coal has a siliceous cement, and contains 

 few primitive stones; Lettres sur les Montagnes, 

 3 1 . Saussure made the same observation on those 

 which he found on the descent of Trient, which 

 interceded between the primary and secondary 

 mountains, 2 Sauss. 699- He even remarked 

 long before, that primeval and secondary rocks 

 were almost always separated by a sand-stone or 

 farcilite, 1 Sauss. 594. Where the secondary 

 strata are calcareous, the semiprotolite has a cal- 

 careous cement; see Lehm. 168. Semiprotolite 

 is always red, by reason of the ferruginous par- 

 ticles by which it is cemented; its diffusion or 



