De Re Metallica Part 17

_Cobaltum -- Smallite* } _Cadmia metallica_ cineraceum_ (CoAs_{2}) } } _Cobaltum nigrum_ -- Abolite* } } _Cobaltum ferri -- Cobalt.i.te } colore_ (Coa.s.s) }

_Zinc.u.m_ _Zinck_ Zinc Zinc

_Liquor Candidus _Conterfei_ Zinc See note 48, p. 408 ex fornace ...

etc._

_Atramentum -- Goslarite *Native white sutorium, (Zn SO_{4}) vitriol candidum, potissimum reperitur Goselariae_

_Spodos _Geeler zechen } Either natural { Grey _spodos_ subterranea rauch_ } or artificial { cinerea_ } zinc oxides, { } no doubt { _Spodos _Schwartzer } containing { Black _spodos_ subterranea zechen rauch, } a.r.s.enical { nigra_ auff dem } oxides { Altenberge } { nennet man in } { kis_ } { } { _Spodos _Grauer zechen } { Green _spodos_ subterranea rauch_ } { viridis_ } { } { _Pompholyx_ _Huttenrauch_ } { _Pompholyx_ (see } { note 26, p. 394)

As seen from the following quotations from Agricola, on _cadmia_ and cobalt, there was infinite confusion as to the zinc, cobalt, and a.r.s.enic minerals; nor do we think any good purpose is served by adding to the already lengthy discussion of these pa.s.sages, the obscurity of which is natural to the state of knowledge; but we reproduce them as giving a fairly clear idea of the amount of confusion then existing. It is, however, desirable to bear in mind that the mines familiar to Agricola abounded in complex mixtures of cobalt, nickel, a.r.s.enic, bis.m.u.th, zinc, and antimony. Agricola frequently mentions the garlic odour from _cadmia metallica_, which, together with the corrosive qualities mentioned below, would obviously be due to a.r.s.enic. _Bermannus_ (p. 459). "This kind of pyrites miners call _cobaltum_, if it be allowed to me to use our German name. The Greeks call it _cadmia_. The juices, however, out of which pyrites and silver are formed, appear to solidify into one body, and thus is produced what they call _cobaltum_. There are some who consider this the same as pyrites, because it is almost the same. There are some who distinguish it as a species, which pleases me, for it has the distinctive property of being extremely corrosive, so that it consumes the hands and feet of the workmen, unless they are well protected, which I do not believe that pyrites can do. Three kinds are found, and distinguished more by the colour than by other properties; they are black (abolite?), grey (smallite?), and iron colour (cobalt glance?). Moreover, it contains more silver than does pyrites...."

_Bermannus_ (p. 431). "It (a sort of pyrites) is so like the colour of galena that not without cause might anybody have doubt in deciding whether it be pyrites or galena.... Perhaps this kind is neither pyrites nor galena, but has a genus of its own. For it has not the colour of pyrites, nor the hardness. It is almost the colour of galena, but of entirely different components. From it there is made gold and silver, and a great quant.i.ty is dug out from Reichenstein which is in Silesia, as was lately reported to me. Much more is found at Raurici, which they call _zinc.u.m_; which species differs from pyrites, for the latter contains more silver than gold, the former only gold, or hardly any silver."

(_De Natura Fossilium_, p. 170). "_Cadmia fossilis_ has an odour like garlic" ... (p. 367). "We now proceed with _cadmia_, not the _cadmia fornacis_ (furnace accretions) of which I spoke in the last book, nor the _cadmia fossilis_ (calamine) devoid of metal, which is used to colour copper, whose nature I explained in Book V, but the metallic mineral (_fossilis metallica_), which Pliny states to be an ore from which copper is made. The Ancients have left no record that another metal could be smelted from it. Yet it is a fact that not only copper but also silver may be smelted from it, and indeed occasionally both copper and silver together. Sometimes, as is the case with pyrites, it is entirely devoid of metal. It is frequently found in copper mines, but more frequently still in silver mines. And there are likewise veins of _cadmia_ itself.... There are several species of the _cadmia fossilis_ just as there were of _cadmia fornac.u.m_. For one kind has the form of grapes and another of broken tiles, a third seems to consist of layers.

But the _cadmia fossilis_ has much stronger properties than that which is produced in the furnaces. Indeed, it often possesses such highly corrosive power that it corrodes the hands and feet of the miners. It, therefore, differs from pyrites in colour and properties. For pyrites, if it does not contain vitriol, is generally either of a gold or silver colour, rarely of any other. _Cadmia_ is either black or brown or grey, or else reddish like copper when melted in the furnace.... For this _cadmia_ is put in a suitable vessel, in the same way as quicksilver, so that the heat of the fire will cause it to sublimate, and from it is made a black or brown or grey body which the Alchemists call 'sublimated _cadmia_' (_cadmiam sublimatam_). This possesses corrosive properties of the highest degree. Cognate with _cadmia_ and pyrites is a compound which the Noricians and Rhetians call _zinc.u.m_. This contains gold and silver, and is either red or white. It is likewise found in the Sudetian mountains, and is devoid of those metals.... With this _cadmia_ is naturally related mineral _spodos_, known to the Moor Serapion, but unknown to the Greeks; and also _pompholyx_--for both are produced by fire where the miners, breaking the hard rocks in drifts, tunnels, and shafts, burn the _cadmia_ or pyrites or galena or other similar minerals. From _cadmia_ is made black, brown, and grey _spodos_; from pyrites, white _pompholyx_ and _spodos_; from galena is made yellow or grey _spodos_. But _pompholyx_ produced from copper stone (_lapide aeroso_) after some time becomes green. The black _spodos_, similar to soot, is found at Altenberg in Meissen. The white _pompholyx_, like wool which floats in the air in summer, is found in Hildesheim in the seams in the rocks of almost all quarries except in the sandstone. But the grey and the brown and the yellow _pompholyx_ are found in those silver mines where the miners break up the rocks by fire. All consist of very fine particles which are very light, but the lightest of all is white _pompholyx_."

QUARTZ MINERALS.

_Quarzum_ ("which _Quertz oder Quartz Quartz (see note Latins call kiselstein_ 15, p. 380) _silex_")

_Silex_ _Hornstein oder Flinty or jaspery Hornstone feurstein_ quartz

_Crystallum_ _Crystal_ Clear crystals Crystal

_Achates_ _Achat_ Agate Agate

_Sarda_ _Carneol_ Carnelian Carnelian

_Jaspis_ _Jaspis_ Part coloured _Jaspis_ quartz, part jade

_Murrhina_ _Chalcedonius_ Chalcedony Chalcedony

_Coticula_ _Goldstein_ A black silicious Touchstone (see stone note 37, p. 252)

_Amethystus_ _Amethyst_ Amethyst Amethyst

LIME MINERALS.

_Lapis } _Gips_ Gypsum Gypsum specularis_ } } _Gypsum_ }

_Marmor_ _Marmelstein_ Marble Marble

_Marmor _Alabaster_ Alabaster Alabaster alabastrites_

_Marmor glarea_ -- Calcite (?) Calc spar(?)

_Saxum calcis_ _Kalchstein_ Limestone Limestone

_Marga_ _Mergel_ Marl Marl

_Tophus_ _Toffstein oder Sintry _Tophus_ (see note topstein_ limestones, 13, p. 233) stalagmites, etc.

MISCELLANEOUS.

_Amiantus_ _Federwis, pliant Usually asbestos Asbestos salamanderhar_

_Magnetis_ _Silberweis oder } Mica *Mica katzensilber_ } } _Bracteolae -- } magnetidi simile_ } } _Mica_ _Katzensilber } oder glimmer_ }

_Silex ex eo ictu -- Feldspar *Feldspar ferri facile ignis elicitur....

excubus figuris_

_Medulla saxorum_ _Steinmarck_ Kaolinite Porcelain clay

_Fluores (lapides _Flusse_ Fluorspar *Fluorspar gemmarum simili)_ (see note 15, p. 380)

_Marmor in _Spat_ Barite *Heavy spar metallis repertum_

Apart from the above, many other minerals are mentioned in other chapters, and some information is given with regard to them in the footnotes.

[9] Three _librae_ of silver per _centumpondium_ would be equal to 875 ounces per short ton.

[10] As stated in note on p. 2, Agricola divided "stones so called" into four kinds; the first, common stones in which he included lodestone and jasper or bloodstone; the second embraced gems; the third were decorative stones, such as marble, porphyry, etc.; the fourth were rocks, such as sandstone and limestone.

LODESTONE. (_Magnes_; _Interpretatio_ gives _Siegelstein oder magnet_).

The lodestone was well-known to the Ancients under various names--_magnes_, _magnetis_, _heraclion_, and _sideritis_. A review of the ancient opinions as to its miraculous properties would require more s.p.a.ce than can be afforded. It is mentioned by many Greek writers, including Hippocrates (460-372 B.C.) and Aristotle; while Theophrastus (53), Dioscorides (V, 105), and Pliny (x.x.xIV, 42, x.x.xVI, 25) describe it at length. The Ancients also maintained the existence of a stone, _theamedes_, having repellant properties, and the two were supposed to exist at times in the same stone.

EMERY. (_Smiris_; _Interpretatio_ gives _smirgel_). Agricola (_De Natura Fossilium_, p. 265) says: "The ring-makers polish and clean their hard gems with _smiris_. The glaziers use it to cut their gla.s.s into sheets.

It is found in the silver mines of Annaberg in Meissen and elsewhere."

Stones used for polis.h.i.+ng gems are noted by the ancient authors, and Dana (Syst. of Mineralogy, p. 211) considers the stone of Armenia, of Theophrastus (77), to be emery, although it could quite well be any hard stone, such as Novaculite--which is found in Armenia. Dioscorides (V, 166) describes a stone with which the engravers polish gems.

LAPIS JUDAICUS. (_Interpretatio_ gives _Juden stein_). This was undoubtedly a fossil, possibly a _pentremites_. Agricola (_De Natura Fossilium_, p. 256) says: "It is shaped like an acorn, from the obtuse end to the point proceed raised lines, all equidistant, etc." Many fossils were included among the semi-precious stones by the Ancients.

Pliny (x.x.xVII, 55, 66, 73) describes many such stones, among them the _balanites_, _phoenicitis_ and the _pyren_, which resemble the above.

TROCHITIS. (_Interpretatio_ gives _spangen oder rederstein_). This was also a fossil, probably crinoid stems. Agricola (_De Natura Fossilium_, p. 256) describes it: "_Trochites_ is so called from a wheel, and is related to _lapis judaicus_. Nature has indeed given it the shape of a drum (_tympanum_). The round part is smooth, but on both ends as it were there is a module from which on all sides there extend radii to the outer edge, which corresponds with the radii. These radii are so much raised that it is fluted. The size of these _trochites_ varies greatly, for the smallest is so little that the largest is ten times as big, and the largest are a digit in length by a third of a digit in thickness ...

when immersed in vinegar they make bubbles."

[11] The "extraordinary earths" of Agricola were such substances as ochres, tripoli, fullers earth, potters' clay, clay used for medicinal purposes, etc., etc.

[12] Presumably the ore-body dips into a neighbouring property.

[13] The various kinds of iron tools are described in great detail in Book VI.

[14] Fire-setting as an aid to breaking rock is of very ancient origin, and moreover it persisted in certain German and Norwegian mines down to the end of the 19th century--270 years after the first application of explosives to mining. The first specific reference to fire-setting in mining is by Agatharchides (2nd century B.C.) whose works are not extant, but who is quoted by both Diodorus Siculus and Photius, for which statement see note 8, p. 279. Pliny (x.x.xIII, 21) says: "Occasionally a kind of silex is met with, which must be broken with fire and vinegar, or as the tunnels are filled with suffocating fumes and smoke, they frequently use bruising machines, carrying 150 _librae_ of iron." This combination of fire and vinegar he again refers to (XXIII, 27), where he dilates in the same sentence on the usefulness of vinegar for breaking rock and for salad dressing. This myth about breaking rocks with fire and vinegar is of more than usual interest, and its origin seems to be in the legend that Hannibal thus broke through the Alps. Livy (59 B.C., 17 A.D.) seems to be the first to produce this myth in writing; and, in any event, by Pliny's time (23-79 A.D.) it had become an established method--in literature. Livy (XXI, 37) says, in connection with Hannibal's crossing of the Alps: "They set fire to it (the timber) when a wind had arisen suitable to excite the fire, then when the rock was hot it was crumbled by pouring on vinegar (_infuso aceto_). In this manner the cliff heated by the fire was broken by iron tools, and the declivities eased by turnings, so that not only the beasts of burden but also the elephants could be led down." Hannibal crossed the Alps in 218 B.C. and Livy's account was written 200 years later, by which time Hannibal's memory among the Romans was generally surrounded by Herculean fables. Be this as it may, by Pliny's time the vinegar was generally accepted, and has been ceaselessly debated ever since. Nor has the myth ceased to grow, despite the remarks of Gibbon, Lavalette, and others. A recent historian (Hennebert, _Histoire d'

Annibal_ II, p. 253) of that famous engineer and soldier, soberly sets out to prove that inasmuch as literal acceptance of ordinary vinegar is impossible, the Phoenicians must have possessed some mysterious high explosive. A still more recent biographer swallows this argument _in toto_. (Morris, "Hannibal," London, 1903, p. 103). A study of the commentators of this pa.s.sage, although it would fill a volume with sterile words, would disclose one generalization: That the real scholars have pa.s.sed over the pa.s.sage with the comment that it is either a corruption or an old woman's tale, but that hosts of soldiers who set about the biography of famous generals and campaigns, almost to a man take the pa.s.sage seriously, and seriously explain it by way of the rock being limestone, or snow, or by the use of explosives, or other foolishness. It has been proposed, although there are grammatical objections, that the text is slightly corrupt and read _infosso acuto_, instead of _infuso aceto_, in which case all becomes easy from a mining point of view. If so, however, it must be a.s.sumed that the corruption occurred during the 20 years between Livy and Pliny.

By the use of fire-setting in recent times at Konigsberg (Arthur L.

Collins, "Fire-setting," Federated Inst. of Mining Engineers, Vol. V, p.

82) an advance of from 5 to 20 feet per month in headings was accomplished, and on the score of economy survived the use of gunpowder, but has now been abandoned in favour of dynamite. We may mention that the use of gunpowder for blasting was first introduced at Schemnitz by Caspar Weindle, in 1627, but apparently was not introduced into English mines for nearly 75 years afterward, as the late 17th century English writers continue to describe fire-setting.