same ore is soaked with water and smeared over it and beaten on with shovels ;
some workers, if they cannot obtain such fine sand, cover the pile with charcoal-dust, just as do charcoal-burners. But at Goslar, the pile, when it has
been built up in the form of a cone, is smeared with atr amentum sutorium
rubrum0, which is made by the leaching of roasted pyrites soaked with water.
In some districts the ore is roasted once, in others twice, in others three times,
as its hardness may require. At Goslar, when pyrites is roasted for the third
time, that which is placed on the top of the pyre exudes a certain greenish,
dry, rough, thin substance, as I have elsewhere written6 ; this is no more
easily burned by the fire than is asbestos. Very often also, water is put on
iAtramentum sutorium rubrum. Literally, this would be red vitriol. The German
translation gives rot kupferwasser, also red vitriol. We must confess that we cannot make
this substance out, nor can we find it mentioned in the other works of Agricola. It may be
the residue from leaching roasted pyrites for vitriol, which would be reddish oxide of iron.
6The statement " elsewhere " does not convey very much more information. It
is (De Nat. Fos., p. 253) : " When Goslar pyrites and Eisleben (copper) schists are placed on
" the pyre and roasted for the third time, they both exude a certain substance which is of a
"greenish colour, dry, rough, and fibrous (tenue). This substance, like asbestos, is not
" consumed by the fire. The schists exude it more plentifully than the pyrites." The
Interpretatio gives federwis, as the German equivalent of amiantus (asbestos). This term was
used for the feathery alum efflorescence on aluminous slates.