De Re Metallica Part 16

Blue and green copper minerals were distinguished by all the ancient mineralogists. Theophrastus, Dioscorides, Pliny, etc., all give sufficient detail to identify their _cya.n.u.s_ and _caeruleum_ partly with modern azurite, and their _chrysocolla_ partly with the modern mineral of the same name. However, these terms were also used for vegetable pigments, as well as for the pigments made from the minerals. The Greek origin of _chrysocolla_ (_chrysos_, gold and _kolla_, solder) may be blamed with another and distinct line of confusion, in that this term has been applied to soldering materials, from Greek down to modern times, some of the ancient mineralogists even a.s.serting that the copper mineral _chrysocolla_ was used for this purpose. Agricola uses _chrysocolla_ for borax, but is careful to state in every case (see note xx., p. x): "_Chrysocolla_ made from _nitrum_," or "_Chrysocolla_ which the Moors call Borax." Dioscorides and Pliny mention substances which were evidently copper sulphides, but no description occurs prior to Agricola that permits a hazard as to different species.

LEAD MINERALS.

_Plumbarius lapis_ _Glantz_ Galena Galena

_Galena_ _Glantz und Galena Galena pleiertz_

_Plumb.u.m nigrum } _Pleiertz oder Cerussite Yellow lead ore lutei coloris_ } pleischweis_ (PbCO_{3}) } _Plumbago } metallica_ }

_Cerussa_ _Pleiweis_ Artificial White-lead (see White-lead note 4, p. 440)

_Ochra facticia_ _Pleigeel_ Ma.s.sicot (Pb O) *Lead-ochre (see or _ochra note 8, p. 232) plumbaria_

_Molybdaena_ } _Herdplei_ Part litharge Hearth-lead (see } note 37, p. 476) _Plumbago } fornacis_ }

_Spuma argenti_ } _Glett_ Litharge Litharge (see note } on p. 465) _Lithargyrum_ }

_Minium _Menning_ Minium Red-lead (see note secundarium_ (Pb_{3}O_{4}) 7, p. 232)

So far as we can determine, all of these except the first three were believed by Agricola to be artificial products. Of the first three, galena is certain enough, but while he obviously was familiar with the alteration lead products, his descriptions are inadequate and much confused with the artificial oxides. Great confusion arises in the ancient mineralogies over the terms _molybdaena_, _plumbago_, _plumb.u.m_, _galena_, and _spuma argenti_, all of which, from Roman mineralogists down to a century after Agricola, were used for lead in some form.

Further discussion of such confusion will be found in note 37, p. 476.

Agricola in _Bermannus_ and _De Natura Fossilium_, devotes pages to endeavouring to reconcile the ancient usages of these terms, and all the confusion existing in Agricola's time was thrice confounded when the names _molybdaena_ and _plumbago_ were a.s.signed to non-lead minerals.

TIN. Agricola knew only one tin mineral: _Lapilli nigri ex quibus conflatur plumb.u.m candidum_, _i.e._, "Little black stones from which tin is smelted," and he gives the German equivalent as _zwitter_, "tin-stone." He describes them as being of different colours, but probably due to external causes.

ANTIMONY. (_Interpretatio_,--_spiesglas_.) The _stibi_ or _stibium_ of Agricola was no doubt the sulphide, and he follows Dioscorides in dividing it into male and female species. This distinction, however, is impossible to apply from the inadequate descriptions given. The mineral and metal known to Agricola and his predecessors was almost always the sulphide, and we have not felt justified in using the term antimony alone, as that implies the refined product, therefore, we have adopted either the Latin term or the old English term "grey antimony." The smelted antimony of commerce sold under the latter term was the sulphide. For further notes see p. 428.

BIs.m.u.tH*. _Plumb.u.m cinereum_ (_Interpretatio_,--_bis.m.u.t_). Agricola states that this mineral occasionally occurs native, "but more often as a mineral of another colour" (_De Nat. Fos._, p. 337), and he also describes its commonest form as black or grey. This, considering his localities, would indicate the sulphide, although he a.s.signs no special name to it. Although bis.m.u.th is mentioned before Agricola in the _Nutzliche Bergbuchlin_, he was the first to describe it (see p. 433).

QUICKSILVER. Apart from native quicksilver, Agricola adequately describes cinnabar only. The term used by him for the mineral is _minium nativum_ (_Interpretatio_,--_bergzin.o.ber_ or _cinnabaris_). He makes the curious statement _(De Nat. Fos._ p. 335) that _rudis_ quicksilver also occurs liver-coloured and blackish,--probably gangue colours. (See p.

432).

a.r.s.eNICAL MINERALS. Metallic a.r.s.enic was unknown, although it has been maintained that a substance mentioned by Albertus Magnus (_De Rebus Metallicis_) was the metallic form. Agricola, who was familiar with all Albertus's writings, makes no mention of it, and it appears to us that the statement of Albertus referred only to the oxide from sublimation.

Our word "a.r.s.enic" obviously takes root in the Greek for orpiment, which was also used by Pliny (x.x.xIV, 56) as _arrhenic.u.m_, and later was modified to _a.r.s.enic.u.m_ by the Alchemists, who applied it to the oxide.

Agricola gives the following in _Bermannus_ (p. 448), who has been previously discussing realgar and orpiment:--"_Ancon_: Avicenna also has a white variety. _Bermannus_: I cannot at all believe in a mineral of a white colour; perhaps he was thinking of an artificial product; there are two which the Alchemists make, one yellow and the other white, and they are accounted the most powerful poisons to-day, and are called only by the name _a.r.s.enic.u.m_." In _De Natura Fossilium_ (p. 219) is described the making of "the white variety" by sublimating orpiment, and also it is noted that realgar can be made from orpiment by heating the latter for five hours in a sealed crucible. In _De Re Metallica_ (Book X.), he refers to _auripigmentum factic.u.m_, and no doubt means the realgar made from orpiment. The four minerals of a.r.s.enic base mentioned by Agricola were:--

_Auripigmentum_ _Operment_ Orpiment Orpiment (As_{2}S_{3})

_Sandaraca_ _Rosgeel_ Realgar (As S) Realgar

_a.r.s.enic.u.m_ _a.r.s.enik_ Artificial White a.r.s.enic a.r.s.enical oxide

_Lapis subrutilus _Mistpuckel_ a.r.s.enopyrite *Mispickel atque ... (Fe As S) splendens_

We are somewhat uncertain as to the identification of the last. The yellow and red sulphides, however, were well known to the Ancients, and are described by Aristotle, Theophrastus (71 and 89), Dioscorides (V, 81), Pliny (x.x.xIII, 22, etc.); and Strabo (XII, 3, 40) mentions a mine of them near Pompeiopolis, where, because of its poisonous character none but slaves were employed. The Ancients believed that the yellow sulphide contained gold--hence the name _auripigmentum_, and Pliny describes the attempt of the Emperor Caligula to extract the gold from it, and states that he did obtain a small amount, but unprofitably. So late a mineralogist as Hill (1750) held this view, which seemed to be general. Both realgar and orpiment were important for pigments, medicinal purposes, and poisons among the Ancients. In addition to the above, some a.r.s.enic-cobalt minerals are included under _cadmia_.

IRON MINERALS.

_Ferrum purum_ _Gedigen eisen_ Native iron *Native iron

_Terra ferria_ _Eisen ertz_ } Various soft and } Ironstone } hard iron } _Ferri vena_ _Eisen ertz_ } ores, probably } } mostly hemat.i.te} _Galenae genus _Eisen glantz_ } } tertium omnis } } metalli } } inanissimi_ } } } } _Schistos_ _Glaskopfe oder } } blutstein_ } } } } _Ferri vena _Leber ertz_ } } jecoris colore_ } }

_Ferrugo_ _Rust_ Part limonite Iron rust

_Magnes_ _Siegelstein Magnet.i.te Lodestone oder magnet_

_Ochra nativa_ _Berg geel_ Limonite Yellow ochre or ironstone

_Haemat.i.tes_ _Blut stein_ { Part hemat.i.te Bloodstone or { Part jasper ironstone

_Schistos_ _Glas kopfe_ Part limonite Ironstone

_Pyrites_ _Kis_ Pyrites Pyrites

_Pyrites argenti _wa.s.ser oder Marcasite *White iron coloris_ weisser kis_ pyrites

_Misy_ _Gel atrament_ Part copiapite _Misy_ (see note on p. 573)

_Sory_ _Graw und Partly a _Sory_ (see note schwartz decomposed iron on p. 573) atrament_ pyrite

_Melanteria_ _Schwartz und Melanterite _Melanteria_ (see grau atrament_ (native vitriol) note on p. 573)

The cla.s.sification of iron ores on the basis of exterior characteristics, chiefly hardness and brilliancy, does not justify a more narrow rendering than "ironstone." Agricola (_De Nat. Fos._, Book V.) gives elaborate descriptions of various iron ores, but the descriptions under any special name would cover many actual minerals.

The subject of pyrites is a most confused one; the term originates from the Greek word for fire, and referred in Greek and Roman times to almost any stone that would strike sparks. By Agricola it was a generic term in somewhat the same sense that it is still used in mineralogy, as, for instance, iron pyrite, copper pyrite, etc. So much was this the case later on, that Henckel, the leading mineralogist of the 18th Century, ent.i.tled his large volume _Pyritologia_, and in it embraces practically all the sulphide minerals then known. The term _marcasite_, of mediaeval Arabic origin, seems to have had some vogue prior and subsequent to Agricola. He, however, puts it on one side as merely a synonym for pyrite, nor can it be satisfactorily defined in much better terms.

Agricola apparently did not recognise the iron base of pyrites, for he says (_De Nat. Fos._, p. 366): "Sometimes, however, pyrites do not contain any gold, silver, copper, or lead, and yet it is not a pure stone, but a compound, and consists of stone and a substance which is somewhat metallic, which is a species of its own." Many varieties were known to him and described, partly by their other metal a.s.sociation, but chiefly by their colour.

CADMIA. The minerals embraced under this term by the old mineralogists form one of the most difficult chapters in the history of mineralogy.

These complexities reached their height with Agricola, for at this time various new minerals cla.s.sed under this heading had come under debate.

All these minerals were later found to be forms of zinc, cobalt, or a.r.s.enic, and some of these minerals were in use long prior to Agricola.

From Greek and Roman times down to long after Agricola, bra.s.s was made by cementing zinc ore with copper. Aristotle and Strabo mention an earth used to colour copper, but give no details. It is difficult to say what zinc mineral the _cadmium_ of Dioscorides (V, 46) and Pliny (x.x.xIV, 2), really was. It was possibly only furnace calamine, or perhaps blende for it was a.s.sociated with copper. They amply describe _cadmia_ produced in copper furnaces, and _pompholyx_ (zinc oxide). It was apparently not until Theophilus (1150) that the term _calamina_ appears for that mineral. Precisely when the term "zinc," and a knowledge of the metal, first appeared in Europe is a matter of some doubt; it has been attributed to Paracelsus, a contemporary of Agricola (see note on p.

409), but we do not believe that author's work in question was printed until long after. The quotations from Agricola given below, in which _zinc.u.m_ is mentioned in an obscure way, do not appear in the first editions of these works, but only in the revised edition of 1559. In other words, Agricola himself only learned of a substance under this name a short period before his death in 1555. The metal was imported into Europe from China prior to this time. He however does describe actual metallic zinc under the term _conterfei_, and mentions its occurrence in the cracks of furnace walls. (See also notes on p. 409).

The word cobalt (German _kobelt_) is from the Greek word _cobalos_, "mime," and its German form was the term for gnomes and goblins. It appears that the German miners, finding a material (Agricola's "corrosive material") which injured their hands and feet, connected it with the goblins, or used the term as an epithet, and finally it became established for certain minerals (see note 21, p. 214, on this subject).

The first written appearance of the term in connection with minerals, appears in Agricola's _Bermannus_ (1530). The first practical use of cobalt was in the form of _zaffre_ or cobalt blue. There seems to be no mention of the substance by the Greek or Roman writers, although a.n.a.lyses of old colourings show some traces of cobalt, but whether accidental or not is undetermined. The first mention we know of, was by Biringuccio in 1540 (_De La Pirotechnia_, Book II, Chap. IX.), who did not connect it with the minerals then called _cobalt_ or _cadmia_.

"_Zaffera_ is another mineral substance, like a metal of middle weight, which will not melt alone, but accompanied by vitreous substances it melts into an azure colour so that those who colour gla.s.s, or paint vases or glazed earthenware, make use of it. Not only does it serve for the above-mentioned operations, but if one uses too great a quant.i.ty of it, it will be black and all other colours, according to the quant.i.ty used." Agricola, although he does not use the word _zaffre_, does refer to a substance of this kind, and in any event also missed the relation between _zaffre_ and cobalt, as he seems to think (_De Nat. Fos._, p.

347) that _zaffre_ came from bis.m.u.th, a belief that existed until long after his time. The cobalt of the Erzgebirge was of course, intimately a.s.sociated with this mineral. He says, "the slag of bis.m.u.th, mixed together with metalliferous substances, which when melted make a kind of gla.s.s, will tint gla.s.s and earthenware vessels blue." _Zaffre_ is the roasted mineral ground with sand, while _smalt_, a term used more frequently, is the fused mixture with sand.

The following are the substances mentioned by Agricola, which, we believe, relate to cobalt and zinc minerals, some of them a.r.s.enical compounds. Other a.r.s.enical minerals we give above.

_Cadmia fossilis_ _Calmei_; _lapis Calamine Calamine calaminaris_

_Cadmia metallica_ _Kobelt_ Part cobalt *_Cadmia metallica_

_Cadmia fornacis_ _Mitlere und Furnace Furnace accretions obere accretions or offenbruche_ furnace calamine

_Bituminosa _Kobelt des (Mannsfeld copper _Bituminosa cadmia_ cadmia_ bergwacht_ schists) (see note 4, p. 273)

_Galena inanis_ _Blende_ Sphalerite* *Blende (Zn S)