FOOTNOTES:

FOOTNOTES:[Pg 353][1]The history of the fusion of ores and of metals is the history of individual processes, and such information as we have been able to discover upon the individual methods previous to Agricola we give on the pages where such processes are discussed. In general the records of the beginnings of metallurgy are so nebular that, if one wishes to shirk the task, he can adopt the explanation of William Pryce one hundred and fifty years ago: "It is very probable that the nature and use of Metals were not revealed to Adam in his state of innocence: the toil and labour necessary to procure and use those implements of the iron age could not be known, till they made part of the curse incurred by his fall: 'In the sweat of thy face shalt thou eat bread, till thou return unto the ground; in sorrow shalt thou eat of it all the days of thy life' (Genesis). That they were very early discovered, however, is manifest from the Mosaick account of Tubal Cain, who was the first instructor of every artificer in Brass [sic] and Iron" (Mineralogia Cornubiensis, p. 2).It is conceivable that gold could be found in large enough pieces to have had general use in pre-historic times, without fusion; but copper, which was also in use, must have been smelted, and therefore we must assume a considerable development of human knowledge on the subject prior to any human record. Such incidental mention as exists after record begins does not, of course, extend to the beginning of any particular branch of the art—in fact, special arts obviously existed long before such mention, and down to the complete survey of the state of the art by Agricola our dates are necessarily "prior to" some first mention in literature, or "prior to" the known period of existing remains of metallurgical operations. The scant Egyptian records, the Scriptures, and the Shoo King give a little insight prior to 1000B.C.The more extensive Greek literature of about the 5th to the 3rd centuriesB.C., together with the remains of Greek mines, furnish another datum point of view, and the Roman and Greek writers at the beginning of the Christian era give a still larger view. After them our next step is to the Monk Theophilus and the Alchemists, from the 12th to the 14th centuries. Finally, the awakening of learning at the end of the 15th and the beginning of the 16th centuries, enables us for the first time to see practically all that was known. The wealth of literature which exists subsequent to this latter time makes history thereafter a matter of some precision, but it is not included in this undertaking. Considering the great part that the metals have played in civilization, it is astonishing what a minute amount of information is available on metallurgy. Either the ancient metallurgists were secretive as to their art, or the ancient authors despised such common things, or, as is equally probable, the very partial preservation of ancient literature, by painful transcription over a score of centuries, served only for those works of more general interest. In any event, if all the direct or indirect material on metallurgy prior to the 15th century were compiled, it would not fill 40 pages such as these.[Pg 354]It may be of service to give a tabular summary indicating approximately the time when evidence of particular operations appear on the historical horizon:Gold washed from alluvialPrior to recorded civilizationCopper reduced from ores by smeltingPrior to recorded civilizationBitumen mined and usedPrior to recorded civilizationTin reduced from ores by smeltingPrior to 3500 B.C.Bronze madePrior to 3500 B.C.Iron reduced from ores by smeltingPrior to 3500 B.C.Soda mined and usedPrior to 3500 B.C.Gold reduced from ores by concentrationPrior to 2500 B.C.Silver reduced from ores by smeltingPrior to 2000 B.C.Lead reduced from ores by smeltingPrior to 2000 B.C. (perhaps prior to 3500 B.C.)Silver parted from lead by cupellationPrior to 2000 B.C.Bellows used in furnacesPrior to 1500 B.C.Steel producedPrior to 1000 B.C.Base metals separated from ores by water concentrationPrior to 500 B.C.Gold refined by cupellationPrior to 500 B.C.Sulphide ores smelted for leadPrior to 500 B.C.Mercury reduced from ores by (?)Prior to 400 B.C.White-lead made with vinegarPrior to 300 B.C.Touchstone known for determining gold and silver finenessPrior to 300 B.C.Quicksilver reduced from ore by distillationPrior to Christian EraSilver parted from gold by cementation with saltPrior to "Brass made by cementation of copper and calaminePrior to "Zinc oxides obtained from furnace fumes by construction of dust chambersPrior to "Antimony reduced from ores by smelting (accidental)Prior to "Gold recovered by amalgamationPrior to "Refining of copper by repeated fusionPrior to "Sulphide ores smelted for copperPrior to "Vitriol (blue and green) madePrior to "Alum madePrior to "Copper refined by oxidation and polingPrior to 1200 A.D.Gold parted from copper by cupelling with leadPrior to 1200 A.D.Gold parted from silver by fusion with sulphurPrior to 1200 A.D.Manufacture of nitric acid andaqua regiaPrior to 1400 A.D.Gold parted from silver by nitric acidPrior to 1400 A.D.Gold parted from silver with antimony sulphidePrior to 1500 A.D.Gold parted from copper with sulphurPrior to 1500 A.D.Silver parted from iron with antimony sulphidePrior to 1500 A.D.First text book on assayingPrior to 1500 A.D.Silver recovered from ores by amalgamationPrior to 1500 A.D.Separation of silver from copper by liquationPrior to 1540 A.D.Cobalt and manganese used for pigmentsPrior to 1540 A.D.Roasting copper ores prior to smeltingPrior to 1550 A.D.Stamp-mill usedPrior to 1550 A.D.Bismuth reduced from orePrior to 1550 A.D.Zinc reduced from ore (accidental)Prior to 1550 A.D.Further, we believe it desirable to sketch at the outset the development of metallurgical appliances as a whole, leaving the details to special footnotes; otherwise a comprehensive view of the development of such devices is difficult to grasp.We can outline the character of metallurgical appliances at various periods in a few words. It is possible to set up a description of the imaginary beginning of the[Pg 355]"bronze age" prior to recorded civilization, starting with the savage who accidentally built a fire on top of some easily reducible ore, and discovered metal in the ashes, etc.; but as this method has been pursued times out of number to no particular purpose, we will confine ourselves to a summary of such facts as we can assemble. "Founders' hoards" of the bronze age are scattered over Western Europe, and indicate that smelting was done in shallow pits with charcoal. With the Egyptians we find occasional inscriptions showing small furnaces with forced draught, in early cases with a blow-pipe, but later—about 1500B.C.—with bellows also. The crucible was apparently used by the Egyptians in secondary melting, such remains at Mt. Sinai probably dating before 2000B.C.With the advent of the Prophets, and the first Greek literature—9th to 7th centuryB.C.—we find frequent references to bellows. The remains of smelting appliances at Mt. Laurion (500-300B.C.) do not indicate much advance over the primitive hearth; however, at this locality we do find evidence of the ability to separate minerals by specific gravity, by washing crushed ore over inclined surfaces with a sort of buddle attachment. Stone grinding-mills were used to crush ore from the earliest times of Mt. Laurion down to the Middle Ages. About the beginning of the Christian era the writings of Diodorus, Strabo, Dioscorides, and Pliny indicate considerable advance in appliances. Strabo describes high stacks to carry off lead fumes; Dioscorides explains a furnace with a dust-chamber to catchpompholyx(zinc oxide); Pliny refers to the upper and lower crucibles (a forehearth) and to the pillars and arches of the furnaces. From all of their descriptions we may conclude that the furnaces had then reached some size, and were, of course, equipped with bellows. At this time sulphide copper and lead ores were smelted; but as to fluxes, except lead for silver, and lead and soda for gold, we have practically no mention. Charcoal was the universal fuel for smelting down to the 18th century. Both Dioscorides and Pliny describe a distillation apparatus used to recover quicksilver. A formidable list of mineral products and metal alloys in use, indicate in themselves considerable apparatus, of the details of which we have no indication; in the main these products were lead sulphide, sulphate, and oxide (red-lead and litharge); zinc oxide; iron sulphide, oxide and sulphate; arsenic and antimony sulphides; mercury sulphide, sulphur, bitumen, soda, alum and potash; and of the alloys, bronze, brass, pewter, electrum and steel.From this period to the period of the awakening of learning our only light is an occasional gleam from Theophilus and the Alchemists. The former gave a more detailed description of metallurgical appliances than had been done before, but there is little vital change apparent from the apparatus of Roman times. The Alchemists gave a great stimulus to industrial chemistry in the discovery of the mineral acids, and described distillation apparatus of approximately modern form.The next period—the Renaissance—is one in which our descriptions are for the first time satisfactory, and a discussion would be but a review ofDe Re Metallica.[2]Seefootnote 2, p. 267, on verbs used for roasting.[Pg 356][3]Agricola has here either forgotten to take into account his three-palm-thick furnace walls, which will make the length of this long wall sixty-one feet, or else he has included this foot and a half in each case in the six-foot distance between the furnaces, so that the actual clear space is only four and a half feet between the furnace with four feet on the ends.[Pg 358][4]The paucity of terms in Latin for describing structural members, and the consequent repetition of "beam" (trabs), "timber" (tignum), "billet" (tigillum), "pole" (asser), with such modifications as small, large, and transverse, and with long explanatory clauses showing their location, renders the original very difficult to follow. We have, therefore, introduced such terms as "posts," "tie-beams," "sweeps," "levers," "rafters," "sills," "moulding," "braces," "cleats," "supports," etc., as the context demands.[Pg 361][5]This set of rafters appears to start from the longitudinal beam.[Pg 362][6]Devices for creating an air current must be of very old invention, for it is impossible to conceive of anything but the crudest melting of a few simple ores without some forced draft. Wilkinson (The Ancient Egyptians,II, p. 316) gives a copy of an illustration of a foot-bellows from a tomb of the time of Thotmes III. (1500B.C.). The rest of the world therefore, probably obtained them from the Egyptians. They are mentioned frequently in the Bible, the most pointed reference to metallurgical purposes being Jeremiah (VI, 29): "The bellows are burned, the lead is consumed in the fire; the founder melteth in vain; for the wicked are not plucked away." Strabo (VII, 3) states that Ephorus ascribed the invention of bellows to Anacharsis—a Thracian prince of about 600B.C.[Pg 366][7]This whole arrangement could be summarized by the word "hinge."[Pg 371][8]The rim of this wheel is obviously made of segments fixed in two layers; the "disc" meaning the aggregate of segments on either side of the wheel.[Pg 376][9]It has not been considered necessary to introduce the modern termtwyerin these descriptions, as the literal rendering is sufficiently clear.[10]Ferruminata. These accretions are practically always near the hearth, and would correspond to English "sows," and therefore that term has been adopted. It will be noted that, like most modern metallurgists, Agricola offers no method for treating them. Pliny (XXXIV, 37) describes a "sow," and uses the verbferruminare(to weld or solder): "Some say that in the furnace there are certain masses of stone which become soldered together, and that the copper fuses around it, the mass not becoming liquid unless it is transferred to another furnace; it thus forms a sort of knot, as it were, of the metal."[Pg 377][11]What are known in English as "crucible," "furnace well," "forehearth," "dipping-pot," "tapping-pot," "receiving-pot," etc., are in the text allcatinus,i.e., crucible. For easier reading, however, we have assigned the names indicated in the context.[Pg 379][12]Panes ex pyrite conflati. While the termmattewould cover most cases where this expression appears, and in many cases would be more expressive to the modern reader, yet there are instances where the expression as it stands indicates its particular origin, and it has been, therefore, considered advisable to adhere to the literal rendering.[13]Molybdaena. Seenote 37, p. 476. It was the saturated furnace bottoms from cupellation.[14]The four elements were earth, air, fire, and water.[Pg 380][15]"Stones which easily melt in the fire." Nowhere inDe Re Metallicadoes the author explain these substances. However in theInterpretatio(p. 465) he gives three genera or orders with their German equivalents, as follows:—"Lapides qui igni liquescunt primi generis,—Schöne flüsse; secundi,—flüsse zum schmeltzen flock quertze; tertii,—quertze oder kiselstein."We confess our inability to make certain of most of the substances comprised in the first and second orders. We consider they were in part fluor-spar, and in any event the third order embraced varieties of quartz, flint, and silicious material generally. As the matter is of importance from a metallurgical point of view, we reproduce at some length Agricola's own statements on the subject fromBermannusandDe Natura Fossilium. In the latter (p. 268) he states: "Finally there now remain those stones which I call 'stones which easily melt in the fire,' because when thrown into hot furnaces they flow (fluunt). There are three orders (genera) of these. The first resembles the transparent gems; the second is not similar, and is generally not translucent; it is translucent in some part, and in rare instances altogether translucent. The first is sparingly found in silver and other mines; the second abounds in veins of its own. The third genus is the material from which glass is made, although it can also be made out of the other two. The stones of the first order are not only transparent, but are also resplendent, and have the colours of gems, for some resemble crystal, others emerald, heliotrope, lapis lazuli, amethyst, sapphire, ruby,chrysolithus,morion(cairngorm?), and other gems, but they differ from them in hardness.... To the first genus belongs thelapis alabandicus(modern albandite?), if indeed it was different from the alabandic carbuncle. It can be melted, according to Pliny, in the fire, and fused for the preparation of glass. It is black, but verging upon purple. It comes from Caria, near Alabanda, and from Miletus in the same province. The second order of stones does not show a great variety of colours, and seldom beautiful ones, for it is generally white, whitish, greyish, or yellowish. Because these (stones) very readily melt in the fire, they are added to the ores from which the metals are smelted. The small stones found in veins, veinlets, and the spaces between the veins, of the highest peaks of the Sudetic range (Suditorum montium), belong partly to this genus and partly to the first. They differ in size, being large and small; and in shape, some being round or angular or pointed; in colour they are black or ash-grey, or yellow, or purple, or violet, or iron colour. All of these are lacking in metals. Neither do the little stones contain any metals which are usually found in the streams where gold dust is collected by washing.... In the rivers where are collected the small stones from which tin is smelted, there are three genera of small stones to be found, all somewhat rounded and of very light weight, and devoid of all metals. The largest are black, both on the outside and inside, smooth and brilliant like a mirror; the medium-sized are either bluish black or ash-grey; the smallest are of a yellowish colour, somewhat like a silkworm. But because both the former and the latter stones are devoid of metals, and fly to pieces under the blows of the hammer, we classify them as sand or gravel. Glass is made from the stones of the third order, and particularly from sand. For when this is thrown into the heated furnace it is melted by the fire.... This kind of stone is either found[Pg 381]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 transparent, 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 fromBermannus(p. 458) can leave little doubt as to the first or second order being in part fluor-spar. Agricola derived the namefluoresfromfluo"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 themfluores, 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 redfluores, 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,fluoresof 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 dissimilar, 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 offluores?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 Breitenbrunn, which is near Schwarzenberg. Moreover, fromfluoresthey can make colours which artists use."[Pg 384][16]Stannum. (Interpretatio,—werck, modernwerk). This term has been rendered throughout as "silver-lead" or "silver-lead alloy." It was the argentiferous lead suitable for cupellation. Agricola, in using it in this sense, was no doubt following his interpretation of its use by Pliny. Further remarks upon this subject will be found innote 33, p. 473.[Pg 386][17]Expirare,—to exhale or blow out.[Pg 388][18]Rhetos. The ancient Rhaetia comprised not only the greater part of Tyrol, but also parts of Switzerland and Lombardy. The mining section was, however, in Tyrol.[19]Noricumwas a region south of the Danube, embracing not only modern Styria, but also parts of Austria, Salzberg, and Carinthia.[20]Onedrachmaof gold to acentumpondiumwould be (if we assume these were Roman weights) 3 ozs. 1 dwt. Troy per short ton. One-halfunciaof silver would be 12 ozs. 3 dwts. per short ton.[Pg 390][21]For discussion of these fluxes see note page232.[22]Carni. Probably the people of modern Austrian Carniola, which lies south of Styria and west of Croatia.[23]Historical Note on Smelting Lead and Silver.—The history of lead and silver smelting is by no means a sequent array of exact facts. With one possible exception, lead does not appear upon the historical horizon until long after silver, and yet their metallurgy is so inextricably mixed that neither can be considered wholly by itself. As silver does not occur native in any such quantities as would have supplied the amounts possessed by the Ancients, we must, therefore, assume its reduction by either (1) intricate chemical processes, (2) amalgamation, (3) reduction with copper, (4) reduction with lead. It is impossible to conceive of the first with the ancient knowledge of chemistry; the second (seenote 12, p. 297) does not appear to have been known until after Roman times; in any event, quicksilver appears only at about 400B.C.The third was impossible, as the parting of silver from copper without lead involves metallurgy only possible during the last century. Therefore, one is driven to the conclusion that the fourth case obtained, and that the lead must have been known practically contemporaneously with silver. There is a leaden figure exhibited in the British Museum among the articles recovered from the Temple of Osiris at Abydos, and considered to be of the Archaic period—prior to 3800B.C.The earliest known Egyptian silver appears to be a necklace of beads, supposed to be of the XII. Dynasty (2400B.C.), which is described in the 17th Memoir, Egyptian Exploration Fund (London, 1898, p. 22). With this exception of the above-mentioned lead specimen, silver articles antedate positive evidence of lead by nearly a millennium, and if we assume lead as a necessary factor in silver production, we must conclude it was known long prior to any direct (except the above solitary possibility) evidence of lead itself. Further, if we are to conclude its necessary association with silver, we must assume a knowledge of cupellation for the parting of the two metals. Lead is mentioned in 1500B.C.[Pg 391]among the spoil captured by Thotmes III. Leaden objects have frequently been found in Egyptian tombs as early as Rameses III. (1200B.C.). The statement is made by Pulsifer (Notes for a History of Lead, New York 1888, p. 146) that Egyptian pottery was glazed with lead. We have been unable to find any confirmation of this. It may be noted, incidentally, that lead is not included in the metals of the "Tribute of Yü" in the Shoo King (The Chinese Classics, 2500B.C.?), although silver is so included.After 1200 or 1300B.C.evidences of the use of lead become frequent. Moses (NumbersXXXI, 22-23) directs the Israelites with regard to their plunder from the Midianites (1300B.C.): "Only the gold and the silver, the brass [sic], the iron, the tin, and the lead. Everything that may abide the fire, ye shall make it go through the fire, and it shall be clean; nevertheless, it shall be purified with the water of separation, and all that abideth not the fire ye shall make go through the water." Numerous other references occur in the Scriptures (PsalmsXII, 6; ProverbsXVII, 3;XXV, 4; etc.), one of the most pointed from a metallurgical point of view being that of Jeremiah (600B.C.), who says (VI, 29-30): "The bellows are burned, the lead is consumed of the fire; the founder melteth in vain; for the wicked are not plucked away. Reprobate silver shall men call them because the Lord hath rejected them." From the number of his metaphors in metallurgical terms we may well conclude that Jeremiah was of considerable metallurgical experience, which may account for his critical tenor of mind. These Biblical references all point to a knowledge of separating silver and lead. Homer mentions lead (IliadXXIV, 109), and it has been found in the remains of ancient Troy and Mycenae (H. Schliemann, "Troy and its Remains," London, 1875, and "Mycenae," New York, 1877). Both Herodotus (I, 186) and Diodorus (II, 1) speak of the lead used to fix iron clamps in the stone bridge of Nitocris (600B.C.) at Babylon.Our best evidence of ancient lead-silver metallurgy is the result of the studies at Mt. Laurion by Edouard Ardaillon (Mines du Laurion dans l'Antiquité, Paris, 1897). Here the very extensive old workings and the slag heaps testify to the greatest activity. The re-opening of the mines in recent years by a French Company has well demonstrated their technical character, and the frequent mention in Greek History easily determines their date. These deposits of argentiferous galena were extensively worked before 500B.C.and while the evidence of concentration methods is ample, there is but little remaining of the ancient smelters. Enough, however, remains to demonstrate that the galena was smelted in small furnaces at low heat, with forced draught, and that it was subsequently cupelled. In order to reduce the sulphides the ancient smelters apparently depended upon partial roasting in the furnace at a preliminary period in reduction, or else upon the ferruginous character of the ore, or upon both. See notes p.27and p.265. Theognis (6th centuryB.C.) and Hippocrates (5th centuryB.C.) are frequently referred to as mentioning the refining of gold with lead; an inspection of the passages fails to corroborate the importance which has been laid upon them. Among literary evidences upon lead metallurgy of later date, Theophrastus (300B.C.) describes the making of white-lead with lead plates and vinegar. Diodorus Siculus (1st centuryB.C.), in his well-known quotation from Agatharchides (2nd centuryB.C.) with regard to gold mining and treatment in Egypt, describes the refining of gold with lead. (Seenote 8, p. 279.) Strabo (63B.C.-24A.D.) says (III, 2, 8): "The furnaces for[Pg 392]silver are constructed lofty in order that the vapour, which is dense and pestilent, may be raised and carried off." And again (III, 2, 10), in quoting from Polybius (204-125B.C.): "Polybius, speaking of the silver mines of New Carthage, tells us that they are extremely large, distant from the city about 20 stadia, and occupy a circuit of 400 stadia; that there are 40,000 men regularly engaged in them, and that they yield daily to the Roman people (a revenue of) 25,000 drachmae. The rest of the process I pass over, as it is too long; but as for the silver ore collected, he tells us that it is broken up and sifted through sieves over water; that what remains is to be again broken, and the water having been strained off it is to be sifted and broken a third time. The dregs which remain after the fifth time are to be melted, and the lead being poured off, the silver is obtained pure. These silver mines still exist; however, they are no longer the property of the State, neither these nor those elsewhere, but are possessed by private individuals. The gold mines, on the contrary, nearly all belong to the State. Both at Castlon and other places there are singular lead mines worked. They contain a small proportion of silver, but not sufficient to pay for the expense of refining" (Hamilton's Trans.). Dioscorides (1st centuryA.D.), among his medicines, describes several varieties of litharge, their origin, and the manner of making white-lead (see on pp.465,440), but he gives no very tangible information on lead smelting. Pliny, at the same period in speaking of silver, (XXXIII, 31), says: "After this we speak of silver, the next folly. Silver is only found in shafts, there being no indications like shining particles as in the case of gold. This earth is sometimes red, sometimes of an ashy colour. It is impossible to melt it except with lead ore (vena plumbi), calledgalena, which is generally found next to silver veins. And this the same agency of fire separates part into lead, which floats on the silver like oil on water." (We have transferred lead and silver in this last sentence, otherwise it means nothing.) Also (XXXIV, 47) he says: "There are two different sources of lead, it being smelted from its own ore, whence it comes without the admixture of any other substance, or else from an ore which contains it in common with silver. The metal, which flows liquid at the first melting in the furnace, is calledstannumthat at the second melting is silver; that which remains in the furnace isgalena, which is added to a third part of the ore. This being again melted, produces lead with a deduction of two-ninths." We have, despite some grammatical objections, rendered this passage quite differently from other translators, none of whom have apparently had any knowledge of metallurgy; and we will not, therefore, take the several pages of space necessary to refute their extraordinary and unnecessary hypotheses. From a metallurgical point of view, two facts must be kept in mind,—first, thatgalenain this instance was the same substance asmolybdaena, and they were both either a variety of litharge or of lead carbonates; second, that thestannumof the Ancients was silver-lead alloy. Therefore, the metallurgy of this paragraph becomes a simple melting of an argentiferous lead ore, its subsequent cupellation, with a return of the litharge to the furnace. Pliny goes into considerable detail as to varieties of litharge, for further notes upon which see p.466. The Romans were most active lead-silver miners, not only in Spain, but also in Britain. There are scores of lead pigs of the Roman era in various English museums, many marked "ex argent." Bruce (The Roman Wall, London, 1852, p. 432) describes some Roman lead furnaces in Cumberland where the draught was secured by driving a tapering tunnel into the hills. The Roman lead slag ran high in metal, and formed a basis for quite an industry in England in the early 18th century (Hunt, British Mining, London, 1887, p. 26, etc.). There is nothing in mediæval literature which carries us further with lead metallurgy than the knowledge displayed by Pliny, until we arrive at Agricola's period. The history of cupellation is specially dealt with in note on p.465.[Pg 394][25]Cadmia. In the German Translation this is given askobelt. It would be of uncertain character, but no doubt partially furnace calamine. (See note on p.112.)[26]Pompholyx. (Interpretatiogives the German asWeisser hütten rauch als ober dem garherde und ober dem kupfer ofen). This was the impure protoxide of zinc deposited in the furnace outlets, and is modern "tutty." The ancient products, no doubt, contained arsenical oxides as well. It was well known to the Ancients, and used extensively for medicinal purposes, they dividing it into two species—pompholyxandspodos. The first adequate description is by Dioscorides (V, 46): "Pompholyxdiffers fromspodosin species, not in genus. Forspodosis blacker, and is often heavier, full of straws and hairs, like the refuse that is swept from the floors of copper smelters. Butpompholyxis fatty, unctuous, white and light enough to fly in the air. Of this there are two kinds—the one inclines to sky blue and is unctuous; the other is exceedingly white, and is extremely light. Whitepompholyxis made every time that the artificer, in the preparation and perfecting of copper (brass?) sprinkles powderedcadmiaupon it to make it more perfect, for the soot which rises being very fine becomespompholyx. Otherpompholyxis made, not only in working copper (brass?), but is also made fromcadmiaby continually blowing with bellows. The manner of doing it is as follows:—The furnace is constructed in a two-storied building, and there is a medium-sized aperture opening to the upper chamber; the building wall nearest the furnace is pierced with a small opening to admit the nozzle of the bellows. The building must have a fair-sized door for the artificer to pass in and out. Another small building must adjoin this, in which are the bellows and the man who works them. Then the charcoal in the furnace is lighted, and the artificer continually throws broken bits ofcadmiafrom the place above the furnace, whilst his assistant, who is below, throws in charcoals, until all of thecadmiainside is consumed. By this means the finest and lightest part of the[Pg 396]stuff flies up with the smoke to the upper chamber, and adheres to the walls of the roof. The substance which is thus formed has at first the appearance of bubbles on water, afterward increasing in size, it looks like skeins of wool. The heaviest parts settle in the bottom, while some fall over and around the furnaces, and some lie on the floor of the building. This latter part is considered inferior, as it contains a lot of earth and becomes full of dirt."Pliny (XXXIV, 33) appears somewhat confused as to the difference between the two species: "That which is calledpompholyxandspodosis found in the copper-smelting furnaces, the difference between them being thatpompholyxis separated by washing, whilespodosis not washed. Some have called that which is white and very lightpompholyx, and it is the soot of copper andcadmia; whereasspodosis darker and heavier. It is scraped from the walls of the furnace, and is mixed with particles of metal, and sometimes with charcoal." (XXXIV, 34.) "The Cyprianspodosis the best. It is formed by fusingcadmiawith copper ore. This being the lightest part of the metal, it flies up in the fumes from the furnace, and adheres to the roof, being distinguished from the soot by its whiteness. That which is less white is immature from the furnace, and it is this which some call 'pompholyx.'" Agricola (De Natura Fossilium, p. 350) traverses much the same ground as the authors previously quoted, and especially recommends thepompholyxproduced when making brass by melting alternate layers of copper and calamine (cadmia fossilis).[27]Oleo, ex fece vini sicca confecto. This oil, made from argol, is probably the same substance mentioned a few lines further on as "wine," distilled by heating argol in a retort. Still further on, salt made from argol is mentioned. It must be borne in mind that this argol was crude tartrates from wine vats, and probably contained a good deal of organic matter. Heating argol sufficiently would form potash, but that the distillation product could be anything effective it is difficult to see.[28]Aqua valens. No doubt mainly nitric acid, the preparation of which is explained at length inBook X, p. 439.[Pg 397][29]Quod cum ignis consumit non modo una cum eo, quae ipsius stibii vis est, aliqua auri particula, sed etiam argenti, si cum auro fuerit permistum, consumitur.The meaning is by no means clear. On p.451is set out the old method of parting silver from gold with antimony sulphide, of which this may be a variation. The silver combines with sulphur, and the reduced antimony forms an alloy with the gold. The added iron and copper would also combine with the sulphur from the antimony sulphide, and no doubt assist by increasing the amount of free collecting agent and by increasing the volume of the matte. (Seenote 17, p. 451.)

[Pg 353][1]The history of the fusion of ores and of metals is the history of individual processes, and such information as we have been able to discover upon the individual methods previous to Agricola we give on the pages where such processes are discussed. In general the records of the beginnings of metallurgy are so nebular that, if one wishes to shirk the task, he can adopt the explanation of William Pryce one hundred and fifty years ago: "It is very probable that the nature and use of Metals were not revealed to Adam in his state of innocence: the toil and labour necessary to procure and use those implements of the iron age could not be known, till they made part of the curse incurred by his fall: 'In the sweat of thy face shalt thou eat bread, till thou return unto the ground; in sorrow shalt thou eat of it all the days of thy life' (Genesis). That they were very early discovered, however, is manifest from the Mosaick account of Tubal Cain, who was the first instructor of every artificer in Brass [sic] and Iron" (Mineralogia Cornubiensis, p. 2).It is conceivable that gold could be found in large enough pieces to have had general use in pre-historic times, without fusion; but copper, which was also in use, must have been smelted, and therefore we must assume a considerable development of human knowledge on the subject prior to any human record. Such incidental mention as exists after record begins does not, of course, extend to the beginning of any particular branch of the art—in fact, special arts obviously existed long before such mention, and down to the complete survey of the state of the art by Agricola our dates are necessarily "prior to" some first mention in literature, or "prior to" the known period of existing remains of metallurgical operations. The scant Egyptian records, the Scriptures, and the Shoo King give a little insight prior to 1000B.C.The more extensive Greek literature of about the 5th to the 3rd centuriesB.C., together with the remains of Greek mines, furnish another datum point of view, and the Roman and Greek writers at the beginning of the Christian era give a still larger view. After them our next step is to the Monk Theophilus and the Alchemists, from the 12th to the 14th centuries. Finally, the awakening of learning at the end of the 15th and the beginning of the 16th centuries, enables us for the first time to see practically all that was known. The wealth of literature which exists subsequent to this latter time makes history thereafter a matter of some precision, but it is not included in this undertaking. Considering the great part that the metals have played in civilization, it is astonishing what a minute amount of information is available on metallurgy. Either the ancient metallurgists were secretive as to their art, or the ancient authors despised such common things, or, as is equally probable, the very partial preservation of ancient literature, by painful transcription over a score of centuries, served only for those works of more general interest. In any event, if all the direct or indirect material on metallurgy prior to the 15th century were compiled, it would not fill 40 pages such as these.[Pg 354]It may be of service to give a tabular summary indicating approximately the time when evidence of particular operations appear on the historical horizon:Gold washed from alluvialPrior to recorded civilizationCopper reduced from ores by smeltingPrior to recorded civilizationBitumen mined and usedPrior to recorded civilizationTin reduced from ores by smeltingPrior to 3500 B.C.Bronze madePrior to 3500 B.C.Iron reduced from ores by smeltingPrior to 3500 B.C.Soda mined and usedPrior to 3500 B.C.Gold reduced from ores by concentrationPrior to 2500 B.C.Silver reduced from ores by smeltingPrior to 2000 B.C.Lead reduced from ores by smeltingPrior to 2000 B.C. (perhaps prior to 3500 B.C.)Silver parted from lead by cupellationPrior to 2000 B.C.Bellows used in furnacesPrior to 1500 B.C.Steel producedPrior to 1000 B.C.Base metals separated from ores by water concentrationPrior to 500 B.C.Gold refined by cupellationPrior to 500 B.C.Sulphide ores smelted for leadPrior to 500 B.C.Mercury reduced from ores by (?)Prior to 400 B.C.White-lead made with vinegarPrior to 300 B.C.Touchstone known for determining gold and silver finenessPrior to 300 B.C.Quicksilver reduced from ore by distillationPrior to Christian EraSilver parted from gold by cementation with saltPrior to "Brass made by cementation of copper and calaminePrior to "Zinc oxides obtained from furnace fumes by construction of dust chambersPrior to "Antimony reduced from ores by smelting (accidental)Prior to "Gold recovered by amalgamationPrior to "Refining of copper by repeated fusionPrior to "Sulphide ores smelted for copperPrior to "Vitriol (blue and green) madePrior to "Alum madePrior to "Copper refined by oxidation and polingPrior to 1200 A.D.Gold parted from copper by cupelling with leadPrior to 1200 A.D.Gold parted from silver by fusion with sulphurPrior to 1200 A.D.Manufacture of nitric acid andaqua regiaPrior to 1400 A.D.Gold parted from silver by nitric acidPrior to 1400 A.D.Gold parted from silver with antimony sulphidePrior to 1500 A.D.Gold parted from copper with sulphurPrior to 1500 A.D.Silver parted from iron with antimony sulphidePrior to 1500 A.D.First text book on assayingPrior to 1500 A.D.Silver recovered from ores by amalgamationPrior to 1500 A.D.Separation of silver from copper by liquationPrior to 1540 A.D.Cobalt and manganese used for pigmentsPrior to 1540 A.D.Roasting copper ores prior to smeltingPrior to 1550 A.D.Stamp-mill usedPrior to 1550 A.D.Bismuth reduced from orePrior to 1550 A.D.Zinc reduced from ore (accidental)Prior to 1550 A.D.Further, we believe it desirable to sketch at the outset the development of metallurgical appliances as a whole, leaving the details to special footnotes; otherwise a comprehensive view of the development of such devices is difficult to grasp.We can outline the character of metallurgical appliances at various periods in a few words. It is possible to set up a description of the imaginary beginning of the[Pg 355]"bronze age" prior to recorded civilization, starting with the savage who accidentally built a fire on top of some easily reducible ore, and discovered metal in the ashes, etc.; but as this method has been pursued times out of number to no particular purpose, we will confine ourselves to a summary of such facts as we can assemble. "Founders' hoards" of the bronze age are scattered over Western Europe, and indicate that smelting was done in shallow pits with charcoal. With the Egyptians we find occasional inscriptions showing small furnaces with forced draught, in early cases with a blow-pipe, but later—about 1500B.C.—with bellows also. The crucible was apparently used by the Egyptians in secondary melting, such remains at Mt. Sinai probably dating before 2000B.C.With the advent of the Prophets, and the first Greek literature—9th to 7th centuryB.C.—we find frequent references to bellows. The remains of smelting appliances at Mt. Laurion (500-300B.C.) do not indicate much advance over the primitive hearth; however, at this locality we do find evidence of the ability to separate minerals by specific gravity, by washing crushed ore over inclined surfaces with a sort of buddle attachment. Stone grinding-mills were used to crush ore from the earliest times of Mt. Laurion down to the Middle Ages. About the beginning of the Christian era the writings of Diodorus, Strabo, Dioscorides, and Pliny indicate considerable advance in appliances. Strabo describes high stacks to carry off lead fumes; Dioscorides explains a furnace with a dust-chamber to catchpompholyx(zinc oxide); Pliny refers to the upper and lower crucibles (a forehearth) and to the pillars and arches of the furnaces. From all of their descriptions we may conclude that the furnaces had then reached some size, and were, of course, equipped with bellows. At this time sulphide copper and lead ores were smelted; but as to fluxes, except lead for silver, and lead and soda for gold, we have practically no mention. Charcoal was the universal fuel for smelting down to the 18th century. Both Dioscorides and Pliny describe a distillation apparatus used to recover quicksilver. A formidable list of mineral products and metal alloys in use, indicate in themselves considerable apparatus, of the details of which we have no indication; in the main these products were lead sulphide, sulphate, and oxide (red-lead and litharge); zinc oxide; iron sulphide, oxide and sulphate; arsenic and antimony sulphides; mercury sulphide, sulphur, bitumen, soda, alum and potash; and of the alloys, bronze, brass, pewter, electrum and steel.From this period to the period of the awakening of learning our only light is an occasional gleam from Theophilus and the Alchemists. The former gave a more detailed description of metallurgical appliances than had been done before, but there is little vital change apparent from the apparatus of Roman times. The Alchemists gave a great stimulus to industrial chemistry in the discovery of the mineral acids, and described distillation apparatus of approximately modern form.The next period—the Renaissance—is one in which our descriptions are for the first time satisfactory, and a discussion would be but a review ofDe Re Metallica.

It is conceivable that gold could be found in large enough pieces to have had general use in pre-historic times, without fusion; but copper, which was also in use, must have been smelted, and therefore we must assume a considerable development of human knowledge on the subject prior to any human record. Such incidental mention as exists after record begins does not, of course, extend to the beginning of any particular branch of the art—in fact, special arts obviously existed long before such mention, and down to the complete survey of the state of the art by Agricola our dates are necessarily "prior to" some first mention in literature, or "prior to" the known period of existing remains of metallurgical operations. The scant Egyptian records, the Scriptures, and the Shoo King give a little insight prior to 1000B.C.The more extensive Greek literature of about the 5th to the 3rd centuriesB.C., together with the remains of Greek mines, furnish another datum point of view, and the Roman and Greek writers at the beginning of the Christian era give a still larger view. After them our next step is to the Monk Theophilus and the Alchemists, from the 12th to the 14th centuries. Finally, the awakening of learning at the end of the 15th and the beginning of the 16th centuries, enables us for the first time to see practically all that was known. The wealth of literature which exists subsequent to this latter time makes history thereafter a matter of some precision, but it is not included in this undertaking. Considering the great part that the metals have played in civilization, it is astonishing what a minute amount of information is available on metallurgy. Either the ancient metallurgists were secretive as to their art, or the ancient authors despised such common things, or, as is equally probable, the very partial preservation of ancient literature, by painful transcription over a score of centuries, served only for those works of more general interest. In any event, if all the direct or indirect material on metallurgy prior to the 15th century were compiled, it would not fill 40 pages such as these.

[Pg 354]It may be of service to give a tabular summary indicating approximately the time when evidence of particular operations appear on the historical horizon:

Gold washed from alluvialPrior to recorded civilizationCopper reduced from ores by smeltingPrior to recorded civilizationBitumen mined and usedPrior to recorded civilizationTin reduced from ores by smeltingPrior to 3500 B.C.Bronze madePrior to 3500 B.C.Iron reduced from ores by smeltingPrior to 3500 B.C.Soda mined and usedPrior to 3500 B.C.Gold reduced from ores by concentrationPrior to 2500 B.C.Silver reduced from ores by smeltingPrior to 2000 B.C.Lead reduced from ores by smeltingPrior to 2000 B.C. (perhaps prior to 3500 B.C.)Silver parted from lead by cupellationPrior to 2000 B.C.Bellows used in furnacesPrior to 1500 B.C.Steel producedPrior to 1000 B.C.Base metals separated from ores by water concentrationPrior to 500 B.C.Gold refined by cupellationPrior to 500 B.C.Sulphide ores smelted for leadPrior to 500 B.C.Mercury reduced from ores by (?)Prior to 400 B.C.White-lead made with vinegarPrior to 300 B.C.Touchstone known for determining gold and silver finenessPrior to 300 B.C.Quicksilver reduced from ore by distillationPrior to Christian EraSilver parted from gold by cementation with saltPrior to "Brass made by cementation of copper and calaminePrior to "Zinc oxides obtained from furnace fumes by construction of dust chambersPrior to "Antimony reduced from ores by smelting (accidental)Prior to "Gold recovered by amalgamationPrior to "Refining of copper by repeated fusionPrior to "Sulphide ores smelted for copperPrior to "Vitriol (blue and green) madePrior to "Alum madePrior to "Copper refined by oxidation and polingPrior to 1200 A.D.Gold parted from copper by cupelling with leadPrior to 1200 A.D.Gold parted from silver by fusion with sulphurPrior to 1200 A.D.Manufacture of nitric acid andaqua regiaPrior to 1400 A.D.Gold parted from silver by nitric acidPrior to 1400 A.D.Gold parted from silver with antimony sulphidePrior to 1500 A.D.Gold parted from copper with sulphurPrior to 1500 A.D.Silver parted from iron with antimony sulphidePrior to 1500 A.D.First text book on assayingPrior to 1500 A.D.Silver recovered from ores by amalgamationPrior to 1500 A.D.Separation of silver from copper by liquationPrior to 1540 A.D.Cobalt and manganese used for pigmentsPrior to 1540 A.D.Roasting copper ores prior to smeltingPrior to 1550 A.D.Stamp-mill usedPrior to 1550 A.D.Bismuth reduced from orePrior to 1550 A.D.Zinc reduced from ore (accidental)Prior to 1550 A.D.

Further, we believe it desirable to sketch at the outset the development of metallurgical appliances as a whole, leaving the details to special footnotes; otherwise a comprehensive view of the development of such devices is difficult to grasp.

We can outline the character of metallurgical appliances at various periods in a few words. It is possible to set up a description of the imaginary beginning of the[Pg 355]"bronze age" prior to recorded civilization, starting with the savage who accidentally built a fire on top of some easily reducible ore, and discovered metal in the ashes, etc.; but as this method has been pursued times out of number to no particular purpose, we will confine ourselves to a summary of such facts as we can assemble. "Founders' hoards" of the bronze age are scattered over Western Europe, and indicate that smelting was done in shallow pits with charcoal. With the Egyptians we find occasional inscriptions showing small furnaces with forced draught, in early cases with a blow-pipe, but later—about 1500B.C.—with bellows also. The crucible was apparently used by the Egyptians in secondary melting, such remains at Mt. Sinai probably dating before 2000B.C.With the advent of the Prophets, and the first Greek literature—9th to 7th centuryB.C.—we find frequent references to bellows. The remains of smelting appliances at Mt. Laurion (500-300B.C.) do not indicate much advance over the primitive hearth; however, at this locality we do find evidence of the ability to separate minerals by specific gravity, by washing crushed ore over inclined surfaces with a sort of buddle attachment. Stone grinding-mills were used to crush ore from the earliest times of Mt. Laurion down to the Middle Ages. About the beginning of the Christian era the writings of Diodorus, Strabo, Dioscorides, and Pliny indicate considerable advance in appliances. Strabo describes high stacks to carry off lead fumes; Dioscorides explains a furnace with a dust-chamber to catchpompholyx(zinc oxide); Pliny refers to the upper and lower crucibles (a forehearth) and to the pillars and arches of the furnaces. From all of their descriptions we may conclude that the furnaces had then reached some size, and were, of course, equipped with bellows. At this time sulphide copper and lead ores were smelted; but as to fluxes, except lead for silver, and lead and soda for gold, we have practically no mention. Charcoal was the universal fuel for smelting down to the 18th century. Both Dioscorides and Pliny describe a distillation apparatus used to recover quicksilver. A formidable list of mineral products and metal alloys in use, indicate in themselves considerable apparatus, of the details of which we have no indication; in the main these products were lead sulphide, sulphate, and oxide (red-lead and litharge); zinc oxide; iron sulphide, oxide and sulphate; arsenic and antimony sulphides; mercury sulphide, sulphur, bitumen, soda, alum and potash; and of the alloys, bronze, brass, pewter, electrum and steel.

From this period to the period of the awakening of learning our only light is an occasional gleam from Theophilus and the Alchemists. The former gave a more detailed description of metallurgical appliances than had been done before, but there is little vital change apparent from the apparatus of Roman times. The Alchemists gave a great stimulus to industrial chemistry in the discovery of the mineral acids, and described distillation apparatus of approximately modern form.

The next period—the Renaissance—is one in which our descriptions are for the first time satisfactory, and a discussion would be but a review ofDe Re Metallica.

[2]Seefootnote 2, p. 267, on verbs used for roasting.

[Pg 356][3]Agricola has here either forgotten to take into account his three-palm-thick furnace walls, which will make the length of this long wall sixty-one feet, or else he has included this foot and a half in each case in the six-foot distance between the furnaces, so that the actual clear space is only four and a half feet between the furnace with four feet on the ends.

[Pg 358][4]The paucity of terms in Latin for describing structural members, and the consequent repetition of "beam" (trabs), "timber" (tignum), "billet" (tigillum), "pole" (asser), with such modifications as small, large, and transverse, and with long explanatory clauses showing their location, renders the original very difficult to follow. We have, therefore, introduced such terms as "posts," "tie-beams," "sweeps," "levers," "rafters," "sills," "moulding," "braces," "cleats," "supports," etc., as the context demands.

[Pg 361][5]This set of rafters appears to start from the longitudinal beam.

[Pg 362][6]Devices for creating an air current must be of very old invention, for it is impossible to conceive of anything but the crudest melting of a few simple ores without some forced draft. Wilkinson (The Ancient Egyptians,II, p. 316) gives a copy of an illustration of a foot-bellows from a tomb of the time of Thotmes III. (1500B.C.). The rest of the world therefore, probably obtained them from the Egyptians. They are mentioned frequently in the Bible, the most pointed reference to metallurgical purposes being Jeremiah (VI, 29): "The bellows are burned, the lead is consumed in the fire; the founder melteth in vain; for the wicked are not plucked away." Strabo (VII, 3) states that Ephorus ascribed the invention of bellows to Anacharsis—a Thracian prince of about 600B.C.

[Pg 366][7]This whole arrangement could be summarized by the word "hinge."

[Pg 371][8]The rim of this wheel is obviously made of segments fixed in two layers; the "disc" meaning the aggregate of segments on either side of the wheel.

[Pg 376][9]It has not been considered necessary to introduce the modern termtwyerin these descriptions, as the literal rendering is sufficiently clear.

[10]Ferruminata. These accretions are practically always near the hearth, and would correspond to English "sows," and therefore that term has been adopted. It will be noted that, like most modern metallurgists, Agricola offers no method for treating them. Pliny (XXXIV, 37) describes a "sow," and uses the verbferruminare(to weld or solder): "Some say that in the furnace there are certain masses of stone which become soldered together, and that the copper fuses around it, the mass not becoming liquid unless it is transferred to another furnace; it thus forms a sort of knot, as it were, of the metal."

[Pg 377][11]What are known in English as "crucible," "furnace well," "forehearth," "dipping-pot," "tapping-pot," "receiving-pot," etc., are in the text allcatinus,i.e., crucible. For easier reading, however, we have assigned the names indicated in the context.

[Pg 379][12]Panes ex pyrite conflati. While the termmattewould cover most cases where this expression appears, and in many cases would be more expressive to the modern reader, yet there are instances where the expression as it stands indicates its particular origin, and it has been, therefore, considered advisable to adhere to the literal rendering.

[13]Molybdaena. Seenote 37, p. 476. It was the saturated furnace bottoms from cupellation.

[14]The four elements were earth, air, fire, and water.

[Pg 380][15]"Stones which easily melt in the fire." Nowhere inDe Re Metallicadoes the author explain these substances. However in theInterpretatio(p. 465) he gives three genera or orders with their German equivalents, as follows:—"Lapides qui igni liquescunt primi generis,—Schöne flüsse; secundi,—flüsse zum schmeltzen flock quertze; tertii,—quertze oder kiselstein."We confess our inability to make certain of most of the substances comprised in the first and second orders. We consider they were in part fluor-spar, and in any event the third order embraced varieties of quartz, flint, and silicious material generally. As the matter is of importance from a metallurgical point of view, we reproduce at some length Agricola's own statements on the subject fromBermannusandDe Natura Fossilium. In the latter (p. 268) he states: "Finally there now remain those stones which I call 'stones which easily melt in the fire,' because when thrown into hot furnaces they flow (fluunt). There are three orders (genera) of these. The first resembles the transparent gems; the second is not similar, and is generally not translucent; it is translucent in some part, and in rare instances altogether translucent. The first is sparingly found in silver and other mines; the second abounds in veins of its own. The third genus is the material from which glass is made, although it can also be made out of the other two. The stones of the first order are not only transparent, but are also resplendent, and have the colours of gems, for some resemble crystal, others emerald, heliotrope, lapis lazuli, amethyst, sapphire, ruby,chrysolithus,morion(cairngorm?), and other gems, but they differ from them in hardness.... To the first genus belongs thelapis alabandicus(modern albandite?), if indeed it was different from the alabandic carbuncle. It can be melted, according to Pliny, in the fire, and fused for the preparation of glass. It is black, but verging upon purple. It comes from Caria, near Alabanda, and from Miletus in the same province. The second order of stones does not show a great variety of colours, and seldom beautiful ones, for it is generally white, whitish, greyish, or yellowish. Because these (stones) very readily melt in the fire, they are added to the ores from which the metals are smelted. The small stones found in veins, veinlets, and the spaces between the veins, of the highest peaks of the Sudetic range (Suditorum montium), belong partly to this genus and partly to the first. They differ in size, being large and small; and in shape, some being round or angular or pointed; in colour they are black or ash-grey, or yellow, or purple, or violet, or iron colour. All of these are lacking in metals. Neither do the little stones contain any metals which are usually found in the streams where gold dust is collected by washing.... In the rivers where are collected the small stones from which tin is smelted, there are three genera of small stones to be found, all somewhat rounded and of very light weight, and devoid of all metals. The largest are black, both on the outside and inside, smooth and brilliant like a mirror; the medium-sized are either bluish black or ash-grey; the smallest are of a yellowish colour, somewhat like a silkworm. But because both the former and the latter stones are devoid of metals, and fly to pieces under the blows of the hammer, we classify them as sand or gravel. Glass is made from the stones of the third order, and particularly from sand. For when this is thrown into the heated furnace it is melted by the fire.... This kind of stone is either found[Pg 381]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 transparent, 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 fromBermannus(p. 458) can leave little doubt as to the first or second order being in part fluor-spar. Agricola derived the namefluoresfromfluo"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 themfluores, 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 redfluores, 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,fluoresof 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 dissimilar, 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 offluores?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 Breitenbrunn, which is near Schwarzenberg. Moreover, fromfluoresthey can make colours which artists use."

Perusal of the following fromBermannus(p. 458) can leave little doubt as to the first or second order being in part fluor-spar. Agricola derived the namefluoresfromfluo"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 themfluores, 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 redfluores, 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,fluoresof 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 dissimilar, 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 offluores?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 Breitenbrunn, which is near Schwarzenberg. Moreover, fromfluoresthey can make colours which artists use."

[Pg 384][16]Stannum. (Interpretatio,—werck, modernwerk). This term has been rendered throughout as "silver-lead" or "silver-lead alloy." It was the argentiferous lead suitable for cupellation. Agricola, in using it in this sense, was no doubt following his interpretation of its use by Pliny. Further remarks upon this subject will be found innote 33, p. 473.

[Pg 386][17]Expirare,—to exhale or blow out.

[Pg 388][18]Rhetos. The ancient Rhaetia comprised not only the greater part of Tyrol, but also parts of Switzerland and Lombardy. The mining section was, however, in Tyrol.

[19]Noricumwas a region south of the Danube, embracing not only modern Styria, but also parts of Austria, Salzberg, and Carinthia.

[20]Onedrachmaof gold to acentumpondiumwould be (if we assume these were Roman weights) 3 ozs. 1 dwt. Troy per short ton. One-halfunciaof silver would be 12 ozs. 3 dwts. per short ton.

[Pg 390][21]For discussion of these fluxes see note page232.

[22]Carni. Probably the people of modern Austrian Carniola, which lies south of Styria and west of Croatia.

[23]Historical Note on Smelting Lead and Silver.—The history of lead and silver smelting is by no means a sequent array of exact facts. With one possible exception, lead does not appear upon the historical horizon until long after silver, and yet their metallurgy is so inextricably mixed that neither can be considered wholly by itself. As silver does not occur native in any such quantities as would have supplied the amounts possessed by the Ancients, we must, therefore, assume its reduction by either (1) intricate chemical processes, (2) amalgamation, (3) reduction with copper, (4) reduction with lead. It is impossible to conceive of the first with the ancient knowledge of chemistry; the second (seenote 12, p. 297) does not appear to have been known until after Roman times; in any event, quicksilver appears only at about 400B.C.The third was impossible, as the parting of silver from copper without lead involves metallurgy only possible during the last century. Therefore, one is driven to the conclusion that the fourth case obtained, and that the lead must have been known practically contemporaneously with silver. There is a leaden figure exhibited in the British Museum among the articles recovered from the Temple of Osiris at Abydos, and considered to be of the Archaic period—prior to 3800B.C.The earliest known Egyptian silver appears to be a necklace of beads, supposed to be of the XII. Dynasty (2400B.C.), which is described in the 17th Memoir, Egyptian Exploration Fund (London, 1898, p. 22). With this exception of the above-mentioned lead specimen, silver articles antedate positive evidence of lead by nearly a millennium, and if we assume lead as a necessary factor in silver production, we must conclude it was known long prior to any direct (except the above solitary possibility) evidence of lead itself. Further, if we are to conclude its necessary association with silver, we must assume a knowledge of cupellation for the parting of the two metals. Lead is mentioned in 1500B.C.[Pg 391]among the spoil captured by Thotmes III. Leaden objects have frequently been found in Egyptian tombs as early as Rameses III. (1200B.C.). The statement is made by Pulsifer (Notes for a History of Lead, New York 1888, p. 146) that Egyptian pottery was glazed with lead. We have been unable to find any confirmation of this. It may be noted, incidentally, that lead is not included in the metals of the "Tribute of Yü" in the Shoo King (The Chinese Classics, 2500B.C.?), although silver is so included.After 1200 or 1300B.C.evidences of the use of lead become frequent. Moses (NumbersXXXI, 22-23) directs the Israelites with regard to their plunder from the Midianites (1300B.C.): "Only the gold and the silver, the brass [sic], the iron, the tin, and the lead. Everything that may abide the fire, ye shall make it go through the fire, and it shall be clean; nevertheless, it shall be purified with the water of separation, and all that abideth not the fire ye shall make go through the water." Numerous other references occur in the Scriptures (PsalmsXII, 6; ProverbsXVII, 3;XXV, 4; etc.), one of the most pointed from a metallurgical point of view being that of Jeremiah (600B.C.), who says (VI, 29-30): "The bellows are burned, the lead is consumed of the fire; the founder melteth in vain; for the wicked are not plucked away. Reprobate silver shall men call them because the Lord hath rejected them." From the number of his metaphors in metallurgical terms we may well conclude that Jeremiah was of considerable metallurgical experience, which may account for his critical tenor of mind. These Biblical references all point to a knowledge of separating silver and lead. Homer mentions lead (IliadXXIV, 109), and it has been found in the remains of ancient Troy and Mycenae (H. Schliemann, "Troy and its Remains," London, 1875, and "Mycenae," New York, 1877). Both Herodotus (I, 186) and Diodorus (II, 1) speak of the lead used to fix iron clamps in the stone bridge of Nitocris (600B.C.) at Babylon.Our best evidence of ancient lead-silver metallurgy is the result of the studies at Mt. Laurion by Edouard Ardaillon (Mines du Laurion dans l'Antiquité, Paris, 1897). Here the very extensive old workings and the slag heaps testify to the greatest activity. The re-opening of the mines in recent years by a French Company has well demonstrated their technical character, and the frequent mention in Greek History easily determines their date. These deposits of argentiferous galena were extensively worked before 500B.C.and while the evidence of concentration methods is ample, there is but little remaining of the ancient smelters. Enough, however, remains to demonstrate that the galena was smelted in small furnaces at low heat, with forced draught, and that it was subsequently cupelled. In order to reduce the sulphides the ancient smelters apparently depended upon partial roasting in the furnace at a preliminary period in reduction, or else upon the ferruginous character of the ore, or upon both. See notes p.27and p.265. Theognis (6th centuryB.C.) and Hippocrates (5th centuryB.C.) are frequently referred to as mentioning the refining of gold with lead; an inspection of the passages fails to corroborate the importance which has been laid upon them. Among literary evidences upon lead metallurgy of later date, Theophrastus (300B.C.) describes the making of white-lead with lead plates and vinegar. Diodorus Siculus (1st centuryB.C.), in his well-known quotation from Agatharchides (2nd centuryB.C.) with regard to gold mining and treatment in Egypt, describes the refining of gold with lead. (Seenote 8, p. 279.) Strabo (63B.C.-24A.D.) says (III, 2, 8): "The furnaces for[Pg 392]silver are constructed lofty in order that the vapour, which is dense and pestilent, may be raised and carried off." And again (III, 2, 10), in quoting from Polybius (204-125B.C.): "Polybius, speaking of the silver mines of New Carthage, tells us that they are extremely large, distant from the city about 20 stadia, and occupy a circuit of 400 stadia; that there are 40,000 men regularly engaged in them, and that they yield daily to the Roman people (a revenue of) 25,000 drachmae. The rest of the process I pass over, as it is too long; but as for the silver ore collected, he tells us that it is broken up and sifted through sieves over water; that what remains is to be again broken, and the water having been strained off it is to be sifted and broken a third time. The dregs which remain after the fifth time are to be melted, and the lead being poured off, the silver is obtained pure. These silver mines still exist; however, they are no longer the property of the State, neither these nor those elsewhere, but are possessed by private individuals. The gold mines, on the contrary, nearly all belong to the State. Both at Castlon and other places there are singular lead mines worked. They contain a small proportion of silver, but not sufficient to pay for the expense of refining" (Hamilton's Trans.). Dioscorides (1st centuryA.D.), among his medicines, describes several varieties of litharge, their origin, and the manner of making white-lead (see on pp.465,440), but he gives no very tangible information on lead smelting. Pliny, at the same period in speaking of silver, (XXXIII, 31), says: "After this we speak of silver, the next folly. Silver is only found in shafts, there being no indications like shining particles as in the case of gold. This earth is sometimes red, sometimes of an ashy colour. It is impossible to melt it except with lead ore (vena plumbi), calledgalena, which is generally found next to silver veins. And this the same agency of fire separates part into lead, which floats on the silver like oil on water." (We have transferred lead and silver in this last sentence, otherwise it means nothing.) Also (XXXIV, 47) he says: "There are two different sources of lead, it being smelted from its own ore, whence it comes without the admixture of any other substance, or else from an ore which contains it in common with silver. The metal, which flows liquid at the first melting in the furnace, is calledstannumthat at the second melting is silver; that which remains in the furnace isgalena, which is added to a third part of the ore. This being again melted, produces lead with a deduction of two-ninths." We have, despite some grammatical objections, rendered this passage quite differently from other translators, none of whom have apparently had any knowledge of metallurgy; and we will not, therefore, take the several pages of space necessary to refute their extraordinary and unnecessary hypotheses. From a metallurgical point of view, two facts must be kept in mind,—first, thatgalenain this instance was the same substance asmolybdaena, and they were both either a variety of litharge or of lead carbonates; second, that thestannumof the Ancients was silver-lead alloy. Therefore, the metallurgy of this paragraph becomes a simple melting of an argentiferous lead ore, its subsequent cupellation, with a return of the litharge to the furnace. Pliny goes into considerable detail as to varieties of litharge, for further notes upon which see p.466. The Romans were most active lead-silver miners, not only in Spain, but also in Britain. There are scores of lead pigs of the Roman era in various English museums, many marked "ex argent." Bruce (The Roman Wall, London, 1852, p. 432) describes some Roman lead furnaces in Cumberland where the draught was secured by driving a tapering tunnel into the hills. The Roman lead slag ran high in metal, and formed a basis for quite an industry in England in the early 18th century (Hunt, British Mining, London, 1887, p. 26, etc.). There is nothing in mediæval literature which carries us further with lead metallurgy than the knowledge displayed by Pliny, until we arrive at Agricola's period. The history of cupellation is specially dealt with in note on p.465.

After 1200 or 1300B.C.evidences of the use of lead become frequent. Moses (NumbersXXXI, 22-23) directs the Israelites with regard to their plunder from the Midianites (1300B.C.): "Only the gold and the silver, the brass [sic], the iron, the tin, and the lead. Everything that may abide the fire, ye shall make it go through the fire, and it shall be clean; nevertheless, it shall be purified with the water of separation, and all that abideth not the fire ye shall make go through the water." Numerous other references occur in the Scriptures (PsalmsXII, 6; ProverbsXVII, 3;XXV, 4; etc.), one of the most pointed from a metallurgical point of view being that of Jeremiah (600B.C.), who says (VI, 29-30): "The bellows are burned, the lead is consumed of the fire; the founder melteth in vain; for the wicked are not plucked away. Reprobate silver shall men call them because the Lord hath rejected them." From the number of his metaphors in metallurgical terms we may well conclude that Jeremiah was of considerable metallurgical experience, which may account for his critical tenor of mind. These Biblical references all point to a knowledge of separating silver and lead. Homer mentions lead (IliadXXIV, 109), and it has been found in the remains of ancient Troy and Mycenae (H. Schliemann, "Troy and its Remains," London, 1875, and "Mycenae," New York, 1877). Both Herodotus (I, 186) and Diodorus (II, 1) speak of the lead used to fix iron clamps in the stone bridge of Nitocris (600B.C.) at Babylon.

Our best evidence of ancient lead-silver metallurgy is the result of the studies at Mt. Laurion by Edouard Ardaillon (Mines du Laurion dans l'Antiquité, Paris, 1897). Here the very extensive old workings and the slag heaps testify to the greatest activity. The re-opening of the mines in recent years by a French Company has well demonstrated their technical character, and the frequent mention in Greek History easily determines their date. These deposits of argentiferous galena were extensively worked before 500B.C.and while the evidence of concentration methods is ample, there is but little remaining of the ancient smelters. Enough, however, remains to demonstrate that the galena was smelted in small furnaces at low heat, with forced draught, and that it was subsequently cupelled. In order to reduce the sulphides the ancient smelters apparently depended upon partial roasting in the furnace at a preliminary period in reduction, or else upon the ferruginous character of the ore, or upon both. See notes p.27and p.265. Theognis (6th centuryB.C.) and Hippocrates (5th centuryB.C.) are frequently referred to as mentioning the refining of gold with lead; an inspection of the passages fails to corroborate the importance which has been laid upon them. Among literary evidences upon lead metallurgy of later date, Theophrastus (300B.C.) describes the making of white-lead with lead plates and vinegar. Diodorus Siculus (1st centuryB.C.), in his well-known quotation from Agatharchides (2nd centuryB.C.) with regard to gold mining and treatment in Egypt, describes the refining of gold with lead. (Seenote 8, p. 279.) Strabo (63B.C.-24A.D.) says (III, 2, 8): "The furnaces for[Pg 392]silver are constructed lofty in order that the vapour, which is dense and pestilent, may be raised and carried off." And again (III, 2, 10), in quoting from Polybius (204-125B.C.): "Polybius, speaking of the silver mines of New Carthage, tells us that they are extremely large, distant from the city about 20 stadia, and occupy a circuit of 400 stadia; that there are 40,000 men regularly engaged in them, and that they yield daily to the Roman people (a revenue of) 25,000 drachmae. The rest of the process I pass over, as it is too long; but as for the silver ore collected, he tells us that it is broken up and sifted through sieves over water; that what remains is to be again broken, and the water having been strained off it is to be sifted and broken a third time. The dregs which remain after the fifth time are to be melted, and the lead being poured off, the silver is obtained pure. These silver mines still exist; however, they are no longer the property of the State, neither these nor those elsewhere, but are possessed by private individuals. The gold mines, on the contrary, nearly all belong to the State. Both at Castlon and other places there are singular lead mines worked. They contain a small proportion of silver, but not sufficient to pay for the expense of refining" (Hamilton's Trans.). Dioscorides (1st centuryA.D.), among his medicines, describes several varieties of litharge, their origin, and the manner of making white-lead (see on pp.465,440), but he gives no very tangible information on lead smelting. Pliny, at the same period in speaking of silver, (XXXIII, 31), says: "After this we speak of silver, the next folly. Silver is only found in shafts, there being no indications like shining particles as in the case of gold. This earth is sometimes red, sometimes of an ashy colour. It is impossible to melt it except with lead ore (vena plumbi), calledgalena, which is generally found next to silver veins. And this the same agency of fire separates part into lead, which floats on the silver like oil on water." (We have transferred lead and silver in this last sentence, otherwise it means nothing.) Also (XXXIV, 47) he says: "There are two different sources of lead, it being smelted from its own ore, whence it comes without the admixture of any other substance, or else from an ore which contains it in common with silver. The metal, which flows liquid at the first melting in the furnace, is calledstannumthat at the second melting is silver; that which remains in the furnace isgalena, which is added to a third part of the ore. This being again melted, produces lead with a deduction of two-ninths." We have, despite some grammatical objections, rendered this passage quite differently from other translators, none of whom have apparently had any knowledge of metallurgy; and we will not, therefore, take the several pages of space necessary to refute their extraordinary and unnecessary hypotheses. From a metallurgical point of view, two facts must be kept in mind,—first, thatgalenain this instance was the same substance asmolybdaena, and they were both either a variety of litharge or of lead carbonates; second, that thestannumof the Ancients was silver-lead alloy. Therefore, the metallurgy of this paragraph becomes a simple melting of an argentiferous lead ore, its subsequent cupellation, with a return of the litharge to the furnace. Pliny goes into considerable detail as to varieties of litharge, for further notes upon which see p.466. The Romans were most active lead-silver miners, not only in Spain, but also in Britain. There are scores of lead pigs of the Roman era in various English museums, many marked "ex argent." Bruce (The Roman Wall, London, 1852, p. 432) describes some Roman lead furnaces in Cumberland where the draught was secured by driving a tapering tunnel into the hills. The Roman lead slag ran high in metal, and formed a basis for quite an industry in England in the early 18th century (Hunt, British Mining, London, 1887, p. 26, etc.). There is nothing in mediæval literature which carries us further with lead metallurgy than the knowledge displayed by Pliny, until we arrive at Agricola's period. The history of cupellation is specially dealt with in note on p.465.

[Pg 394][25]Cadmia. In the German Translation this is given askobelt. It would be of uncertain character, but no doubt partially furnace calamine. (See note on p.112.)

[26]Pompholyx. (Interpretatiogives the German asWeisser hütten rauch als ober dem garherde und ober dem kupfer ofen). This was the impure protoxide of zinc deposited in the furnace outlets, and is modern "tutty." The ancient products, no doubt, contained arsenical oxides as well. It was well known to the Ancients, and used extensively for medicinal purposes, they dividing it into two species—pompholyxandspodos. The first adequate description is by Dioscorides (V, 46): "Pompholyxdiffers fromspodosin species, not in genus. Forspodosis blacker, and is often heavier, full of straws and hairs, like the refuse that is swept from the floors of copper smelters. Butpompholyxis fatty, unctuous, white and light enough to fly in the air. Of this there are two kinds—the one inclines to sky blue and is unctuous; the other is exceedingly white, and is extremely light. Whitepompholyxis made every time that the artificer, in the preparation and perfecting of copper (brass?) sprinkles powderedcadmiaupon it to make it more perfect, for the soot which rises being very fine becomespompholyx. Otherpompholyxis made, not only in working copper (brass?), but is also made fromcadmiaby continually blowing with bellows. The manner of doing it is as follows:—The furnace is constructed in a two-storied building, and there is a medium-sized aperture opening to the upper chamber; the building wall nearest the furnace is pierced with a small opening to admit the nozzle of the bellows. The building must have a fair-sized door for the artificer to pass in and out. Another small building must adjoin this, in which are the bellows and the man who works them. Then the charcoal in the furnace is lighted, and the artificer continually throws broken bits ofcadmiafrom the place above the furnace, whilst his assistant, who is below, throws in charcoals, until all of thecadmiainside is consumed. By this means the finest and lightest part of the[Pg 396]stuff flies up with the smoke to the upper chamber, and adheres to the walls of the roof. The substance which is thus formed has at first the appearance of bubbles on water, afterward increasing in size, it looks like skeins of wool. The heaviest parts settle in the bottom, while some fall over and around the furnaces, and some lie on the floor of the building. This latter part is considered inferior, as it contains a lot of earth and becomes full of dirt."Pliny (XXXIV, 33) appears somewhat confused as to the difference between the two species: "That which is calledpompholyxandspodosis found in the copper-smelting furnaces, the difference between them being thatpompholyxis separated by washing, whilespodosis not washed. Some have called that which is white and very lightpompholyx, and it is the soot of copper andcadmia; whereasspodosis darker and heavier. It is scraped from the walls of the furnace, and is mixed with particles of metal, and sometimes with charcoal." (XXXIV, 34.) "The Cyprianspodosis the best. It is formed by fusingcadmiawith copper ore. This being the lightest part of the metal, it flies up in the fumes from the furnace, and adheres to the roof, being distinguished from the soot by its whiteness. That which is less white is immature from the furnace, and it is this which some call 'pompholyx.'" Agricola (De Natura Fossilium, p. 350) traverses much the same ground as the authors previously quoted, and especially recommends thepompholyxproduced when making brass by melting alternate layers of copper and calamine (cadmia fossilis).

Pliny (XXXIV, 33) appears somewhat confused as to the difference between the two species: "That which is calledpompholyxandspodosis found in the copper-smelting furnaces, the difference between them being thatpompholyxis separated by washing, whilespodosis not washed. Some have called that which is white and very lightpompholyx, and it is the soot of copper andcadmia; whereasspodosis darker and heavier. It is scraped from the walls of the furnace, and is mixed with particles of metal, and sometimes with charcoal." (XXXIV, 34.) "The Cyprianspodosis the best. It is formed by fusingcadmiawith copper ore. This being the lightest part of the metal, it flies up in the fumes from the furnace, and adheres to the roof, being distinguished from the soot by its whiteness. That which is less white is immature from the furnace, and it is this which some call 'pompholyx.'" Agricola (De Natura Fossilium, p. 350) traverses much the same ground as the authors previously quoted, and especially recommends thepompholyxproduced when making brass by melting alternate layers of copper and calamine (cadmia fossilis).

[27]Oleo, ex fece vini sicca confecto. This oil, made from argol, is probably the same substance mentioned a few lines further on as "wine," distilled by heating argol in a retort. Still further on, salt made from argol is mentioned. It must be borne in mind that this argol was crude tartrates from wine vats, and probably contained a good deal of organic matter. Heating argol sufficiently would form potash, but that the distillation product could be anything effective it is difficult to see.

[28]Aqua valens. No doubt mainly nitric acid, the preparation of which is explained at length inBook X, p. 439.

[Pg 397][29]Quod cum ignis consumit non modo una cum eo, quae ipsius stibii vis est, aliqua auri particula, sed etiam argenti, si cum auro fuerit permistum, consumitur.The meaning is by no means clear. On p.451is set out the old method of parting silver from gold with antimony sulphide, of which this may be a variation. The silver combines with sulphur, and the reduced antimony forms an alloy with the gold. The added iron and copper would also combine with the sulphur from the antimony sulphide, and no doubt assist by increasing the amount of free collecting agent and by increasing the volume of the matte. (Seenote 17, p. 451.)

Back to Index Next