De Re Metallica Part 15

Slough = Drainage tunnel.

Sole = Lowest drift.

Stool = Face of a drift or stope.

Winds } Turn } = Winze.

Dippas} Grove = Shaft.

Dutins = Set of timber.

Stemple = Post or stull.

Laths = Lagging.

As examples of the author's coinage and adaptations of terms in this book we may cite:--

_Fossa latens_ = Drift.

_Fossa latens transversa_ = Crosscut.

_Tectum_ = Hangingwall.

_Fundamentum_ = Footwall.

_Tigna per intervalla posita_ = Wall plate.

_Arbores dissectae_ = Lagging.

_Formae_ = Hitches.

We have adopted the term "tunnel" for openings by way of outlet to the mine. The word in this narrow sense is as old as "adit," a term less expressive and not so generally used in the English-speaking mining world. We have for the same reason adopted the word "drift" instead of the term "level" so generally used in America, because that term always leads to confusion in discussion of mine surveys. We may mention, however, that the term "level" is a heritage from the Derbyshire mines, and is of an equally respectable age as "drift."

[2] See note on p. 46-47. The _ca.n.a.les_, as here used, were the openings in the earth, in which minerals were deposited.

[3] This statement, as will appear by the description later on, refers to the depth of winzes or to the distance between drifts, that is "the lift." We have not, however, been justified in using the term "winze,"

because some of these were openings to the surface. As showing the considerable depth of shafts in Agricola's time, we may quote the following from _Bermannus_ (p. 442): "The depths of our shafts forced us to invent hauling machines suitable for them. There are some of them larger and more ingenious than this one, for use in deep shafts, as, for instance, those in my native town of Geyer, but more especially at Schneeberg, where the shaft of the mine from which so much treasure was taken in our memory has reached the depth of about 200 fathoms (feet?), wherefore the necessity of this kind of machinery. _Naevius_: What an enormous depth! Have you reached the Inferno? _Bermannus_: Oh, at Kuttenberg there are shafts more than 500 fathoms (feet?) deep.

_Naevius_: And not yet reached the Kingdom of Pluto?" It is impossible to accept these as fathoms, as this would in the last case represent 3,000 feet vertically. The expression used, however, for fathoms is _pa.s.sus_, presumably the Roman measure equal to 58.1 inches.

[4] _Cavernos_. The Glossary gives _drusen_, our word _drusy_ having had this origin.

[5] _Purum_,--"pure." _Interpretatio_ gives the German as _gedigen_,--"native."

[6] _Rudis_,--"Crude." By this expression the author really means ores very rich in any designated metal. In many cases it serves to indicate the minerals of a given metal, as distinguished from the metal itself.

Our system of mineralogy obviously does not afford an acceptable equivalent. Agricola (_De Nat. Foss._, p. 360) says: "I find it necessary to call each genus (of the metallic minerals) by the name of its own metal, and to this I add a word which differentiates it from the pure (_puro_) metal, whether the latter has been mined or smelted; so I speak of _rudis_ gold, silver, quicksilver, copper, tin, bis.m.u.th, lead, or iron. This is not because I am unaware that Varro called silver _rudis_ which had not yet been refined and stamped, but because a word which will distinguish the one from the other is not to be found."

[7] The reasons for retaining the Latin weights are given in the Appendix on Weights and Measures. A _centumpondium_ weighs 70.6 lbs.

avoirdupois, an _uncia_ 412.2 Troy grains, therefore, this value is equal to 72 ounces 18 pennyweights per short ton.

[8] Agricola mentions many minerals in _De Re Metallica_, but without such description as would make possible a hazard at their ident.i.ty. From his _De Natura Fossilium_, however, and from other mineralogies of the 16th Century, some can be fully identified and others surmised. While we consider it desirable to set out the probable composition of these minerals, on account of the s.p.a.ce required, the reasons upon which our opinion has been based cannot be given in detail, as that would require extensive quotations. In a general way, we have throughout the text studiously evaded the use of modern mineralogical terms--unless the term used to-day is of Agricola's age--and have adopted either old English terms of pre-chemistry times or more loose terms used by common miners.

Obviously modern mineralogic terms imply a precision of knowledge not existing at that period. It must not be a.s.sumed that the following is by any means a complete list of the minerals described by Agricola, but they include most of those referred to in this chapter. His system of mineralogy we have set out in note 4, p. 1, and it requires no further comment here. The grouping given below is simply for convenience and does not follow Agricola's method. Where possible, we tabulate in columns the Latin term used in _De Re Metallica_; the German equivalent given by the Author in either the _Interpretatio_ or the Glossary; our view of the probable modern equivalent based on investigation of his other works and other ancient mineralogies, and lastly the terms we have adopted in the text. The German spelling is that given in the original.

As an indication of Agricola's position as a mineralogist, we mark with an asterisk the minerals which were first specifically described by him.

We also give some notes on matters of importance bearing on the nomenclature used in _De Re Metallica_. Historical notes on the chief metals will be found elsewhere, generally with the discussion of smelting methods. We should not omit to express our indebtedness to Dana's great "System of Mineralogy," in the matter of correlation of many old and modern minerals.

GOLD MINERALS. Agricola apparently believed that there were various gold minerals, green, yellow, purple, black, etc. There is nothing, however, in his works that permits of any attempt to identify them, and his cla.s.sification seems to rest on gangue colours.

SILVER MINERALS.

_Argentum purum in _Gedigen silber_ -- *Native silver venis reperitur_

_Argentum rude_ _Gedigen silber -- _Rudis_ silver, or ertz_ pure silver minerals

_Argentum rude _Glas ertz_ Argent.i.te *Silver glance plumbei coloris_ (Ag_{2}S)

_Argentum rude _Rot gold ertz_ Pyrargyrite *Red silver rubrum_ (Ag_{3}SbS_{3})

_Argentum rude _Durchsichtig Proust.i.te *Ruby silver rubrum rod gulden (Ag_{3}a.s.s_{3}) translucidum_ ertz_

_Argentum rude _Weis rod gulden -- White silver alb.u.m_ ertz: Dan es ist frisch wie offtmals rod gulden ertz pfleget zusein_

_Argentum rude _Gedigen Part Bromyrite Liver-coloured jecoris leberfarbig (Ag Br) silver colore_ ertz_

_Argentum rude _Gedigen -- Yellow silver luteum_ geelertz_

_Argentum rude _Gedigen graw } { *Grey silver cineraceum_ ertz_ } Part Cerargurite { } (Ag Cl) (Horn { _Argentum rude _Gedigen } Silver) Part { *Black silver nigrum_ schwartz ertz_ } Stephanite { } (Ag_{5}SbS_{4}) { _Argentum rude _Gedigen braun } { *Purple silver purpureum_ ertz_ } {

The last six may be in part also alteration products from all silver minerals.

The reasons for indefiniteness in determination usually lie in the failure of ancient authors to give sufficient or characteristic descriptions. In many cases Agricola is sufficiently definite as to a.s.sure certainty, as the following description of what we consider to be silver glance, from _De Natura Fossilium_ (p. 360), will indicate: "Lead-coloured _rudis_ silver is called by the Germans from the word gla.s.s (_glasertz_), not from lead. Indeed, it has the colour of the latter or of galena (_plumbago_), but not of gla.s.s, nor is it transparent like gla.s.s, which one might indeed expect had the name been correctly derived. This mineral is occasionally so like galena in colour, although it is darker, that one who is not experienced in minerals is unable to distinguish between the two at sight, but in substance they differ greatly from one another. Nature has made this kind of silver out of a little earth and much silver. Whereas galena consists of stone and lead containing some silver. But the distinction between them can be easily determined, for galena may be ground to powder in a mortar with a pestle, but this treatment flattens out this kind of _rudis_ silver. Also galena, when struck by a mallet or bitten or hacked with a knife, splits and breaks to pieces; whereas this silver is malleable under the hammer, may be dented by the teeth, and cut with a knife."

COPPER MINERALS.

_Aes purum _Gedigen kupfer_ Native copper Native copper fossile_

_Aes rude _Kupferglas ertz_ Chalcocite *Copper glance plumbei (Cu_{2}S) coloris_

_Chalcitis_ _Rodt atrament_ A decomposed _Chalcitis_ (see copper or notes on p. 573) iron sulphide

_Pyrites aurei } _Geelkis oder { Part chalcopyrite Copper pyrites colore_ } kupferkis_ { (Cu Fe S) part } { bornite _Pyrites aerosus_ } { (Cu_{3}FeS_{3})

_Caeruleum_ _Berglasur_ Azurite Azure

_Chrysocolla_ _Berggrun und { Part chrysocolla Chrysocolla (see schifergrun_ { Part Malachite note 7, p. 560)

_Molochites_ _Molochit_ Malachite Malachite

_Lapis aerarius_ _Kupfer ertz_ -- Copper ore

_Aes caldarium } _Lebeter kupfer_ { When used for rubrum fusc.u.m_ } { an ore, is *Ruby copper ore or } { probably _Aes sui coloris_ } _Rotkupfer_ { cuprite

_Aes nigrum_ _Schwartz kupfer_ Probably CuO from *Black copper oxidation of other minerals

In addition to the above the Author uses the following, which were in the main artificial products:

_Aerugo_ _Grunspan oder Verdigris Verdigris Spanschgrun_

_Aes luteum_ _Gelfarkupfer_ } Impure blister { Unrefined copper } copper { (see note 16, } { p. 511) _Aes caldarium_ _Lebeterkupfer_ } {

_Aeris flos_ _Kupferbraun_ } Cupric oxide { Copper flower } scales { } { _Aeris squama_ _Kupferhammer- } { Copper scale (see schlag_ } { note 9, p. 233)

_Atramentum _Blaw kupfer Chalcanthite Native blue sutorium wa.s.ser_ vitriol (see caeruleum_ or note on p. 572) _chalcanthum_