18 
room viil veyed from the Bay of Finland to St. Petersburg!!* 
Nat. Hist, and now forming the base of the equestrian 
statue of Peter the Great) ; granite in several 
stages of decomposition ; new or regenerated gra¬ 
nite from the Hartz, &c. ; binary aggregates, 
called Granitels by some authors (graphic stone 
from Scotland* Sweden) ; granite mixed with 
other minerals, such as common shorl, garnets, 
aotynolite, chlorite, (large polished pieces of 
granitic rocks, some of them passing over into 
sienite and porphyry)—gneiss of various approxi¬ 
mation to granite on one side, and to micaceous 
shistus on the other; gneiss with garnets, shorl, 
he .—micaceous shistus; the same approaching 
to gneiss on one hand, and clay slate on the 
other, (silvery variety of the latter used for 
roofing in Thuringia). 
(Div. 6.) Continuation of the rocks con¬ 
stituting the slate formation* Oldest or primitive 
clay slate of several colours; variegated (fruit 
or cuckoo slate). Subordinate beds in clay slate: 
novaculite or whet slate, chlorite slate, drawing 
slate, better known by the name of black chalk ; 
flinty slate and Lydian stone ; anthracolite or 
kohlenblende.— Transition slate, mostly from 
the Hartz mountains, (specimen, in which 
it is seen in immediate contact with grey 
wacke, a transition rock of the nature of old 
y v 
sand- 
