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44 SWEDENBORG’S TRAVELS AND DIARIES. [Doc. 205.
similar figures ; it is, however, in the inside very jagged and
streaky. It does not seem to contain any tin whatever, but,
on the contrary, does considerable injury to the tin, if it is
melted with the other ores ; therefore it is cast away as spur
ious and injurious. Thirdly, besides this useless kind of ore,
there is also another common kind, called hermaphrodite
(Zwitter) and maulwacke ; this consists of the meanest or
poorest kind of tin ore ; it looks like common grey rock, ex
cept that there are black or dark yellowish, angular spots in
it. The rock in which these spots occur is of a white and
yellowish colour; these spots appear also scattered over a
barren, shining rock, and they become more distinct, when once
the stone has been submitted to a calcining fire ; the white part
of the stone and the black part of the tin ore are then rendered
more manifest. There is another ore, which can scarcely be
distinguished by the eye from a grey stone with a horny as
pect. It is distinguished by trying it in a vessel by means of
water. In this case the ore is first ground into powder, and
then its heavier parts are separated from the lighter by wash
ings and shakings. By this means it can very easily be seen
how much real tin ore there is in it, and how much stone.
The metals which chiefly adhere to these tin ores, and usually
accompany them, are copper and marcasite, as well as iron ;
the marcasite is cast aside, because it renders the tin brittle
and hard. Some silver also is opened up around the tin ore,
but rarely, and only in the vicinity; a little lead, too, occurs,
but that very rarely.
1. This common kind of ore is calcined or burned for the
first time in the open air. The calcining hearths are almost
square, built of common rock, and larger or smaller at pleasure;
from five to six cords (klafter) of split wood, the pieces
being an ell and a half long, are usually placed under
them ; one klafter is about as much as one pair of horses can
pull. The larger pieces of ore are put on the sides of
the hearths, and the smaller, or sometimes the smaller and
larger mixed, into the interior of the heap. The powder is
likewise put in. In the front part of the heap there is an open
ing near the ground, which is kept open when the fire is first
lighted , but is afterwards closed, in order that the fire may
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