BOOK IX.
381
which the nozzle of the bellows is placed, and by a downward movement
dislodges the ore and the sows from around it.
After a quarter of an hour, when the lead which the assistant has placed
in the forehearth is melted, the master opens the tap-hole of the furnace
with a tapping-bar. This bar is made of iron, is three and a half feet long,
the forward end pointed and a little curved, and the back end hollow so that
into it may be inserted a wooden handle, which is three feet long and thick
enough to be well grasped by the hand. The slag first flows from the furnace
into the forehearth, and in it are stones mixed with metal or with the metal
adhering to them partly altered, the slag also containing earth and solidified
juices. After this the material from the melted pyrites flows out, and then the
molten lead contained in the forehearth absorbs the gold and silver. When
that which has run out has stood for some time in the forehearth, in order
to be able to separate one from the other, the master first either skims off
the slags with the hooked bar or else lifts them off with an iron fork ; the
slags, as they are very light, float on the top. He next draws off the cakes of
melted pyrites, which as they are of medium weight hold the middle place ;
he leaves in the forehearth the alloy of gold or silver with the lead, for these
being the heaviest, sink to the bottom. As, however, there is a difference
" in its own veins, which are occasionally very wide, or else scattered through the mines. It
" is less hard than flint, on account of which no fire can be struck from it. It is not trans" parent, but it is of many colours—that is to say, white, yellowish, ash-grey, brown, black,
" green, blue, reddish or red. This genus of stones occurs here and there in mountainous
" regions, on banks of rivers, and in the fields. Those which are black right through to the
" interior, and not merely on the surface, are more rare ; and very frequently one coloured
" vein is intersected by another of a different colour—for instance, a white one by a red one ;
" the green is often spotted with white, the ash-grey with black, the white with crimson.
" Fragments of these stones are frequently found on the surface of the earth, and in the
" running water they become polished by rubbing against stones of their own or of another
" genus. In this way, likewise, fragments of rocks are not infrequently shaped into spherical
" forms. . . . This stone is put to many uses ; the streets are paved with it, whatever its
" colour ; the blue variety is added to the ash of pines for making those other ashes which are
" used by wool-dyers. The white variety is burned, ground, and sifted, and from this they
" make the sand out of which glass is made. The whiter the sand is, the more useful it is."
Perusal of the following from Bermannus (p. 458) can leave little doubt as to the first or
second order being in part fluor-spar. Agricola derived the name fluorés from fluo "to flow," and
we in turn obtain " fluorite," or "fluorspar," from Agricola. " Bermannus. These stones are
" similar to gems, but less hard. Allow me to explain word for word. Our miners call them
" fluorés, not inappropriately to my mind, for by the heat of fire, like ice in the sun, they
" liquefy and flow away. They are of varied and bright colours. Naevius.—Theophrastus
" says of them that they are made by a conflux in the earth. These red fluorés, to employ
" the words just used by you, are the ruby silver which you showed us before. Bermannus.—At
" the first glance it appears so, although it is not infrequently translucent. Naevius.—Then
" they are rubies ? Bermannus.—Not that either. Naevius.—In what way, then, can they be
" distinguished from rubies ? Bermannus.—Chiefly by this sign, that they glitter more
"feebly when translucent. Those which are not translucent may be distinguished from
" rubies. Moreover, fluorés of all kinds melt when they are subject to the first fire ; rubies
" do not melt in fire. Naevius.—You distinguish well. Bermannus.—You see the other
" kind, of a paler purple colour ? Naevius.—They appear to be an inferior kind of amethyst,
" such as are found in many places in Bohemia. Bermannus.—Indeed, they are not very dis" similar, therefore the common people who do not know amethysts well, set them in rings
" for gems, and they are easily sold. The third kind, as you see here, is white. Naevius.—I
" should have thought it a crystal. Bermannus.—A fourth is a yellow colour, a fifth ash colour,
" a sixth blackish. Some are violet, some green, others gold-coloured. Anton.—What is the
" use of fluorés ? Bermannus.—They are wont to be made use of when metals are smelted,
" as they cause the material in the fire to be much more fluid, exactly like a kind of stone
" which we said is made from pyrites (matte) ; it is, indeed, made not far from here, at Breiten" brunn, which is near Schwarzenberg. Moreover, from fluorés they can make colours which
** artists use."
