MODE xi. GNEISS: $ I 3 



pansion, has broken the other stratifications. 

 However this he, it is certain that gneiss has, in 

 the grand example of the Alps, been found un- 

 der granite confessedly primitive; and they are 

 often found alternating with each other. The 

 lofty mountain of Rosa, which only yields in 

 height to Mont Blanc, instead of being com- 

 posed of arrects or uprights*, that is vertical 

 layers, or plates like the latter, presents, on 

 the contrary, horizontal beds of veined granite, 

 gneiss, and other schistose substances f. 



Intermixed with gneiss are sometimes three 

 principal rocks, all regarded as primitive; lime- 

 stone, siderite either solid or schistose, and por- 

 phyry. But these substances equally appear 

 intermixed with granite, only alternating verti- 

 cally; while in gneiss they present horizontal 

 beds. In the old Egyptian monuments nothing 

 is more common than to find large masses of 

 siderite intermixed with the granite; and even 

 basaltin often penetrates that substance. The 

 Egyptian monuments of mica slate, described 

 by Wad, may perhaps more properly belong to 



gneiss. 



* In a new science new words must be admitted. Saussure, 

 and others, have long lamented the absurdity of vertical leds or 

 layers. Arrects or uprights would supply the deficiency. 



f Sauss. 2138. 



