TRAVELS IN BRAZIL. 



201 



sandstone, but mostly the Jura or shell limestone, which we 

 consider the last member of the first formation, primitive 

 clay-slate, and limestone. At Bodenwehr, the principal mass 

 is a thick clay flotz, in which there is more clay' iron-stone 

 than brown iron-stone. In the base, which, as well as the 

 roof, is quadersandstein, there is also magnetic iron-stone, 

 parti}" disseminated, partly in reniform pieces, in a variety of 

 clay iron-stone mingled with green earth. On the Schin- 

 delloh, near Pullenreuth, on the eastern foot of the Fichtel 

 mountain, there is frequently, instead of the clay, what is 

 called earthy talc of a greyish white, yellow, and red colour, 

 according to its mixture with oxyde of iron. In the cavities 

 of the iron, greyish white amethyst, which often passes into 

 chalcedony, is found on the brown haematite; sometimes, 

 too, green iron- earth is observed on tuberous horn-stone. 

 Who does not here recognise the identity of the iron-stone 

 flotz in Bavaria with that in Brazil, though in the former 

 there are no topazes, no gold, and no pieces of ironglance; 

 and the yellow earth, and the lumps of hardened lithomarge, 

 and the coloured clay, as well as the earthy talc, supply 

 the place of the lithomarge which is so frequent and so 

 variously modified in Brazil ? The parallel between these 

 two formations becomes more complete by the discovery of 

 wavellite in the iron-stone flotz near Villa Rica (Von Esch- 

 wege's Gemalde, p. 31), which has been confirmed to us by 

 the verbal communications of Dr. Pohl. 



Note 4, 



We consider Mr. Von Eschwege's iron mica-slate to 

 be no more an independent kind of rock than the tapanho- 

 acanga. In many parts of Bavaria, for instance, the 

 Fichtelberg, and at Floss, there is granite in which iron- 

 mica supplies the place of the common mica ; but no geo- 

 logist has ever thought of taking it for a distinct kind of 

 rock. It forms layers and partly also Stiickgebirge which 

 belong to the common granite, and are to be considei'ed as 



