426 Geology, 
I have said nothing about the metallurgy of the forma- 
tions, meaning this as a mere introduction to the follow- 
ing extract from Jameson, on the respective ages of the 
various metals and their ores. 
RELATIVE AGE OF METALS.— JAMESON. 
1. Molybdena appears to be the oldest of all the metals. 
It occurs imbedded, in six-sided tables, in granite of the 
oldest formation, in the mountains of Silesia, those of 
Sweden, and it is said also in the primitive granite of 
Cruachan in this country. It also occurs, along with 
tinstone, woolfram and tungsten, in the Saxon and Bohe- 
mian tin formation. That formation lies in granite, which 
from its characters, appears to belong to the newest gra- 
nite formation. This metal is also found in the famous 
iron-mines of Norway ; but we know so little of the geog- 
nostic relations of the rocks in these districts, that we 
cannot as yet determine with any certainty the exact date 
of the molybdena they contain. In Glenelg, I observed 
very small portions of it imbedded in chlorite- slate. Com. 
bined with oxygen, it occurs in small quantity in the 
form of molybdat of lead (yellow lead ore), in the oldest 
flcetz- limestone. 
2. Menachine , the Titanium of chemists. This metal 
appears to be next in age to molybdena, because one of 
its species, Rutile,* occurs in those drusy cavities which 
are not unfrequent in granite mountains of the highest an- 
tiquity, lying in or upon the rock-crystal, adularia, and 
foliated chlorite, with which these cavities are lined. The, 
same species occurs also imbedded in mica-slate and 
sienite. Dr. Reuss, the Bohemian mineralogist, affirms 
that he observed it in the newest ftetz-trap formation, im- 
bedded m basalt ; and this observation is strengthened 
* Frequent in Virginia. 
