the whole country, there lies a bed of sandstone; over the sandstone
lies a bed o f alum-slate; over the alum-slate, and constituting the
uppermost bed in the district, lies a bed of limestone. This consitu-
tion of the floetz part of Nerike is represented in Plate XIII. fig. 4 . The
reader will be able to form some notion o f the structure of Nerike
from the geological map by Hermelin, which we have prefixed to
this chapter.
I was informed that rocks of mica-slate make their appearance in
the southern parts of Nerike, but as I did not visit any o f the spots
where these rocks are to be seen, and indeed was not aware of the
circumstance till after I had left the district altogether and gone to
Stockholm, I had no oportunity of verifying these accounts by my
own examination.
There are several mines in Nerike, chiefly iron mines. They are
situated in the floetz tract, but very near the gneiss rocks,- which may
be traced within a few miles o f them. The most remarkable of these
mines lie near Yinterosa, upon the banks o f the Black River which runs
into the lake Hjelmar; it is called Hesselkulla. The ore is a magnetic
ironstone; the veinstones are quartz, garnet, lime, and felspar.
Hence I conceive this mine to lie in the gneiss; though from the
nature of the country it is scarcely possible to determine the point by
actual inspection. But the gneiss may be seen distinctly within less
than an English mile of the mine. The limestone is sometimes
crystallized, and the most usual varieties o f the crystals are the
chaux corbonatee dodecahedre & metastique of Haiiy. Fluor spar
occurs in this mine, a circumstance that deserves to be mentioned,
because it is a rare mineral in Sweden. It was from this mine also
that a mineral analysed by Ekeberg, and considered by him as a
species o f natrolite, was obtained. It has no resemblance to the
natrolite of the Germans. At first sight it has a striking similarity to
felspar; but whether it possesses the real characters of that mineral
I have not yet assertained. This is one o f many points left for
decision till my specimens arrive. Its colour is greenish-grey ; it
is not ciystallized, but is distinctly foliated, and exhibits a double
cleavage. So that there is reason to believe that its primitive form
may be made out with tolerable accuracy. It scratches glass but is
scratched by felspar; its specific gravity is 2 -746. It melts before the
blowpipe with difficulty into a semitransparent globule. According
to the analysis of Ekeberg its constitutents are as follows:
Silica.............................. 4600
Alumina............................... 2875
Lime. . .............................................................. ...
Oxide o f iron • ° '7 5
Soda...................... |H • • - • • • • • • • - • 5-25
W a t e r . . . . '...................................... 2'25
9&5
The result of this analysis is sufficient to shew us that the mineral
in question is not natrolite. The great proportion of lime is equally
inconsistent with the opinion that it is a variety of felspar. The loss
of weight, which is uncommonly great, was probably owing either
to a portion of soda which escaped, or to an acid which was not
suspected.
There is another iron mine in the neighbourhood called Sanna,
remarkable for the great quantity of arsenic pyrites which it contains.
There were formerly some other iron mines in the neighbourhood of
Orebro ; but they have been abandoned for some time.
To the north of Orebro about ten miles, at a place called Dylta,
there is a depot of pyrites lodged in a quartz rock. From this pyrites
sulphur is separated by means of heat. There is a work erected for
the distillation o f the pyrites and the obtaining o f the sulphur. The process
followed is very simple: the pyrites is exposed to heat in a kind
of low chamber from which there runs a long flue along the surface
of the earth, this flue is lined with wood; when the process is at an
end, the upper covering is removed; and the sulphur swept out. It is
afterwards melted and cast into rolls.
A little to the north of Yinterosa, at Tyslinge, upon the borders o f
a small lake, the structure of the floetz part of Nerike, such as I have
described it, may be distinctly seen. Every person that examines this