BOOK III.
REVIOUSLY I have given much information
concerning the miners, also I have discussed the
choice of localities for mining, for washing sands,
and for evaporating waters ; further, I described
the method of searching for veins. With such
matters I was occupied in the second book ; now I
come to the third book, which is about veins and
stringers, and the seams in the rocks1. The
term "vein" is sometimes used to indicate canales
in the earth, but very often elsewhere by this name I have described that
which may be put in vessels2 ; I now attach a second significance to
these words, for by them I mean to designate any mineral substances which
the earth keeps hidden within her own deep receptacles.
1Modern nomenclature in the description of ore-deposits is so impregnated with modern
views of their origin, that we have considered it desirable in many instances to adopt the
Latin terms used by the author, for we believe this method will allow the reader greater
freedom of judgment as to the author's views. The Latin names retained are usually
expressive even to the non-Latin student. In a general way, a vena profunda is a fissure vein,
a vena dilatata is a bedded deposit, and a vena cumulata an impregnation, or a replacement
or a Stockwerk.' The canales, as will appear from the following footnote, were ore channels.
" The seams of the rocks " (commtssurae saxorum) are very puzzling. The author states, as
appears in the following note, that they are of two kinds,—contemporaneous with the formation
of the rocks, and also of the nature of veinlets. However, as to their supposed relation to
the strike of veins, we can offer no explanation. There are passages in this chapter where
if the word "ore-shoot" were introduced for "seams in the rocks" the text would be intelligible. That is, it is possible to conceive the view that the determination of whether an
east-west vein ran east or ran west was dependent on the dip of the ore-shoot along the
strike. This view, however, is utterly impossible to reconcile with the description and
illustration of commtssurae saxorum given on page 54, where they are defined as the finest
stringers. The following passage from the Nützliche Bergbüchlin (see Appendix),
reads very much as though the dip of ore-shoots was understood at this time in relation to
the direction of veins. " Every vein (gang) has two (outcrops) ausgehen, one of the
" ausgehen is toward daylight along the whole length of the vein, which is called the ausgehen
" of the whole vein. The other ausgehen is contrary to or toward the strike (streichen) of
" the vein, according to its rock (gestein), that is called the gesteins ausgehen ; for instance,
" every vein that has its strike from east to west has its gesteins ausgehen to the east, and
" vice-versa."
Agricola's classification of ore-deposits, after the general distinction between alluvial
and in situ deposits, is based entirely upon form, as will be seen in the quotation below relating
to the origin of canales. The German equivalents in the Glossary are as follows :—
Fissure vein (vena profunda) ...... Gang.
Bedded deposit (vena dilatata) ...... Schwebender gang oder fleize.
Stockwerk or impregnation (vena cumulata)...... Geschute oder stock.
Stringer (fibra)
...... Klufft.
Seams or joints (commtssurae saxorum) ...... Absetzen des gesteins.
It is interesting to note that in De Natura Fossilium he describes coal and salt, and
later in De Re Metallica he describes the Mannsfeld copper schists, as all being venae dilatatae.
This nomenclature and classification is not original with Agricola. Pliny (xxxm, 21) uses
the term vena with no explanations, and while Agricola coined the Latin terms for various
kinds of veins, they are his transliteration of German terms already in use. The Nützliche
Bergbüchlin gives this same classification.
Historical Note on the Theory of Ore Deposits. Prior to Agricola there were
Three schools of explanation of the phenomena of ore deposits, the orthodox followers of the
Genesis, the Greek Philosophers, and the Alchemists. The geology of the Genesis—the
contemporaneous formation of everything—needs no comment other than that for anyone to
Hgtì|:jproposed an alternative to the dogma of the orthodox during the Middle Ages, required
The Latin vena, " vein," is also used by the author for ore ; hence this descriptive
warning as to its intended double use.
