Outlines of Mineralogy

OF A NATURAL SYSTEM OF MINERALOGY.

The Mineral Kingdom conſiſts of the foſſil ſubſtances found in the earth. Theſe are either entirely deſtitute of organic structure, or, having once poſſeſſed it, poſſeſs it no longer: ſuch are the petrefactions.

It is requiſite, for the proper diſcrimination of foſſils, to eſtabliſh certain characters, whereby they may, at all times, and in all places, be diſtinguiſhed from one another. The ſcience that teaches theſe is called Mineralogy.

As in the vegetable kingdom different methods have been formed upon the roots, the leaves, the flowers, the fruit, &c. ſo alſo in Mineralogy 6many methods may be deviſed, and there is no doubt of the utility of contemplating inorganic bodies in every point of view; for the more compariſons are multiplied, the more evidently do reſemblances or differences appear.

But as the chief object of the ſcience is to render foſſils ſubſervient to the uſes of man, it is evident that that method muſt be the beſt which diſplays their component parts: for theſe being well underſtood, we know what to expect from them; we accommodate our deſigns to their nature, and ſpend not our labour and money in vain attempts inconſiſtent with their inherent qualities.

There is a power implanted by the creator in organized bodies, which, upon the acquiſition of proper nutriment, unfolds and evolves the ſtructure which before lay concealed in the fecundated egg or ſeed. Similar veſſels, in each ſpecies, abſorb, convey, and aſſimilate the nouriſhment in the ſame manner; ſo that the appearance and ſtructure remain the ſame, unleſs peculiar cauſes prevent the accuſtomed courſe of things, and produce monſters: but this very rarely happens. Hence it is that the leading features or the external parts agree with the internal properties, 7and when judiciouſly choſen, form ſufficient characteriſtic diſtinctions.

But the formation of foſſils is totally different. Here no ſyſtem of veſſels collects, diſtributes, ſecretes or changes the concurrent particles, but they run together by chance, and are ſolely connected by the power of attraction; they are generally, too, of different kinds, rare and denſe, figured and ſhapeleſs, admitting of every poſſible variety. This general view of the ſubject ſhews us how little external characters can be depended on; but we ſhall more particularly conſider the principal of theſe.

Colour varies exceedingly, as does alſo the ſize of bodies. We cannot ſufficiently wonder at the violence done to nature by the ſtudied ſeparation of earths from ſtones. The conſequence is, that a ſtone of a certain ſize muſt conſtitute one genus, whilſt the ſame thing, reduced to powder, muſt be placed under another genus, which ſhall not be found even in the ſame claſs.

Hardness not unfrequently varies even in the ſame ſpecimen. Soft clay dries in the fire, and at length acquires the hardneſs of flint. Steatites (ſoap-rock) which may be ſcraped with the nail, 8and many other matters harden in the ſame manner, and that ſometimes without any notable loſs of weight; ſo that bodies paſs through every different degree of hardneſs, without any other change of their mixture.

Texture, and external form of the particles, may ſeem at firſt ſight to depend more upon the conſtituent parts; but a calcareous particle, globular or ſhapeleſs, is found, upon the moſt ſcrupulous examination, to poſſeſs the ſame properties as a piece of ſpar; and in another place I have clearly ſhewn, that the ſchirl-like, garnet-like, hyacinthine, twelve-ſided, and other figures, are not unfrequently formed by nature out of the ſame materials^[3]. And if we are liable to deception where ſo great a difference in external forms exiſts, what can we expect from leſs conſtant external qualities?

Superficial characters are therefore inſufficient. They cannot even enable us to diſtinguiſh calcareous from other earths, for the efferveſcence with acids is a chemical mark, and happens, too, in matters of very different natures. To paſs 9over other inſtances, let him who is able diſtinguiſh the plumbum aeratum and plumbum phoſphoratum (§ 182. § 183.) by external appearances only!

But let us not altogether deſpiſe external characters: it is of moment to know and mark them well^[4]. They frequently enable the accuſtomed eye without troubleſome trials to acquire a degree of certainty, which wants only a few ſelect experiments to confirm it. Sometimes alſo the uſe depends upon external properties, evident to our ſenſes, as the hardneſs, the colour, the pellucidity, &c. Theſe therefore may with propriety be joined to thoſe which point out the conſtituent principles.

Claſſes, Genera and Species are therefore to be formed upon the internal nature and compoſition; the varieties upon the external appearances. In ſuch a ſyſtem both methods conveniently agree.

Cronstedt firſt attempted this method, and with great ſucceſs; but afterwards the liquid 10analyſis, in which the illuſtrious Margraaf took the lead, better opened the internal ſecrets of nature; ſo that the excellent work of Cronſtedt now appears to contain many errors; theſe however are not to be attributed to any fault in the author, but to the inſufficiency of his experiments. The attempts of Mr. Pott by fuſion have long been known; but theſe however uſeful in other reſpects, rather tend to confound than to lay open the component parts of bodies.

In methodizing foſſils, compounds ſhould rank under the moſt abundant ingredient. Thus let a and b repreſent the component parts; if the former be the heavier, the compound muſt be placed under the genus of that: but this rule admits of ſeveral exceptions.

Thus, the properties of all ingredients are not of the same intenſity, if I may be allowed the expreſſion; ſome are more powerful or efficacious, ſo as to impreſs the maſs with their own genus and character, though forming leſs than half the weight. In ſuch a caſe the qualities are rather to be conſidered than the quantity, eſpecially if b ſo far from preponderating hardly ever amounts to half the weight.

Argillaceous earth (earth of allum) and magneſia are never found ſeparate, but almoſt always 11mixed with other things ſo that their weight conſtitutes the ſmaller part of the maſs: therefore if the above rule (§ 14.) was rigourouſly adhered to, theſe primitive earths would not be found amongſt the Genera, which would doubtleſs be an abſurdity.

The value of a thing muſt likewiſe be conſidered. Minerals containing gold or ſilver muſt be ranked with thoſe noble metals although they hold three, four, or more times the quantity of heterogeneous matter. Not to mention other examples, pyrites are placed under the genus copper although they contain a much greater quantity of iron. This cuſtom, eſtabliſhed with the univerſal conſent of mineralogiſts, wants indeed a natural foundation, but it ſeems uſeful to miners to retain it; and the more ſo as it is certain that otherwiſe many minerals would be to be sought for under ſtrange and improper titles.

Laſtly, it muſt be remarked, that the ſolid ingredient determines the genus although the menſtruum be greater in quantity. Thus in magneſia vitriolata (Epſom ſalt) the earth gives the Generic name, although the vitriolic acid be the more ponderous. The same holds good in gypſum, allum, &c.

CLASSES OF FOSSILS.

Fossils are of four kinds, viz. ſaline, earthy, inflammable, and metallic; hence ariſe four claſſes.

Salts, or ſaline ſubſtances are more or leſs ſapid, and when finely powdered diſſolve in at leaſt 1000 times their weight of boiling water. They melt in the fire, which for the moſt part changes or deſtroys them^[5].

Earths are inſipid, not ſoluble in water in the degree mentioned above (§ 20) though 13perhaps water in Papin’s digeſtor will diſſolve ſome if not all of them, eſpecially if their ſurface be greatly increaſed by a previous ſolution in and precipitation from ſome other menſtruum. In the chain of nature they are by inſenſible gradation joined to the ſalts, ſo as not to be diſtinguiſhed without artificial limits. Their form is not changed by a moderate heat, nor are they diſſipated by a violent one. Their ſpecific gravity is to water, leſs than 5 to 1.

Inflammable foſſils abound with phlogiſton, do not unite with water, but when pure diſſolve in oils; expoſed to the fire, they ſmoke, generally inflame, are for the moſt part conſumed, and ſometimes totally vaniſh.

Metals when perfect do not diſſolve at all in water; only a few of them in oils, and then only when in part deprived of their phlogiſton. They are the heavieſt of all known ſubſtances, the lighteſt of them weighing more than ſix times its bulk of water.

They melt in the fire with a ſhining ſurface, and in clay veſſels the ſurface is convex.

CLASS I. SALTS.

We begin with the nature and properties of ſaline bodies, for unacquainted with theſe our knowledge of other bodies muſt be exceedingly imperfect. Native ſalts are either acid, alkaline, neutral, earthy or metallic.

Acids may be diſtinguiſhed by their proper taſte; they efferveſce with mild alkalies; and change the blue juices of vegetables and tincture of heliotropium to a red colour^[6].

We are acquainted with many ſpecies of acids, but they are hardly ever found pure in the bowels of the earth, nor can we expect to find them ſo when we conſider how ſoon ſuch powerful menſtrua 15muſt meet with ſubſtances to ſaturate them. Their great abundance and their properties ſhew their various and indiſpenſible uſes in the œconomy of nature.

As mineralogy treats of thoſe bodies which are found under the ſurface of the earth, and as acids in an uncombined ſtate are not found there, it would ſeem proper to exclude them; but the ſame reaſon would likewiſe exclude the primitive earths, ſome of which have never yet been found pure. Therefore in a ſyſtem formed upon the component parts of bodies, a ſhort deſcription of the principal of theſe is not to be diſpenſed with, although they hardly ever preſent themſelves in a ſeparate ſtate.

Vitriolic ACID. When moſt concentrated by artificial means its ſpecific gravity is 2, 125. When pure, has neither colour nor ſmell. Cold ſometimes though very rarely concretes it into a ſolid form; it may be coagulated by nitrous air. This as well as the other acids is beſt known from the compounds it forms with other ſubſtances.

Mr. Vandelli^[7] ſays that it is ſometimes mixed with the ſtreams from the hills in the neighbourhood of Sienna and Viterbo, raiſed no doubt 16by ſubterranean fires; but in general it is united to alkalies (§§ 44, 47, 50,) to earths (§§ 58, 59, 63, 67,) to metals (§§ 69, 70, 72, 73,) or to phlogiſton (§§ 134, 136.)

Phlogiſticated vitriolic ACID (volatile vitriolic acid) is frequently thrown out by the craters of volcanoes; its ſmell ſuffocating and penetrating. The union to phlogiſton and the matter of heat gives it an aerial form, but does not prevent its union with water.

Nitrous ACID is by ſome excluded from the foſſil kingdom, becauſe they ſuppoſe it to be produced from the putrefaction of organic bodies. But theſe bodies when deprived of life are again received amongſt the foſſils, from whence their more fixed parts were originally derived.

In the moſt concentrated ſtate that art can procure it, its ſpecific gravity is 1, 580. Colourleſs when pure; but its ſtrong attraction to phlogiſton renders particular management neceſſary to procure it ſo^[8]. With different proportions of phlogiſton it forms phlogiſticated acid and nitrous air.

17It has never as far as I know been met with diſengaged, unleſs perhaps in water precipitated out of the atmoſphere, but is found united to alkalies (§§ 45, 47, 51 ) or to earths (§§ 60, 64.)

Muriatic ACID (ſpirit of ſalt) is found in great quantity at and under the ſurface of the earth. The ſtrongeſt prepared by art hardly attains a ſpecific gravity of 1, 150. It has a very peculiar and volatile ſmell. Deprived of its ſuperfluous water it aſſumes an aerial form, for phlogiſton ſeems to be one of its conſtituent parts^[9].

It has never been found uncombined (unleſs perhaps like the nitrous acid in water precipitated from the atmoſphere^[10])^[11] but united to alkalies (§§ 46, 49, 52), to earths (§§ 61, 65), or to metals (§§ 74, 161, 175, 191).

Fluor ACID, is obtained by art; its ſpecific gravity never exceeds 1,500, it is very volatile. Its vapours when hot, corrode glaſs; and meeting with moiſture generate, or at leaſt depoſit ſiliceous earth. When deprived of its ſuperfluous water it aſſumes an aerial form^[12]. It has 18never been found diſengaged, but united to calcareous earth forming ſparry fluor^[13] (§ 96) and if I am not miſtaken it enters into the compoſition of ſiliceous earths.

Arſenical ACID, dry; prepared by art; ſpecific gravity 3,391; fuſible and fixed in the fire, until it acquires from the matter of heat ſo much phlogiſton as is neceſſary to convert it into white arſenic. In a moiſt air it deliqueſces.

It is not found uncombined, but united to calx of cobalt (§ 228), and alſo to phlogiſton, forming a brittle arſenical metal (§ 220), and its calx (§ 222).

Molybdæna ACID. This is very probably of metallic origin, though it does not yet appear to which metal it belongs. Seeing that arſenic, a brittle metal, by dephlogiſtication only is changed into an acid, different from all other acids, it is not improbable that other metals may have an acid baſis, although their phlogiſton adhering more ſtrongly has not yet been completely ſeparated.

19How this ſubſtance may be obtained by art does not belong to this place to deſcribe^[14]; but that the acid got from Molybdæna has a metallic nature, and as yet has not been perfectly freed from phlogiſton, is probable from the following conſiderations. 1, Its taſte is acid and at the ſame time metallic. 2, Microcoſmic ſalt and borax are coloured by it, and theſe ſalts are hardly coloured by any thing but metallic calxes. 3, Its decompoſition by means of the phlogiſticated fixed alkaly, which always indicates the preſence of a metal. 4, Its concrete form, and not deliqueſcing, analogous to white arſenic. 5, Its ſpecific gravity 3,460. And very lately M. Hielm by my perſuaſion attempted the reduction and obtained a regulus, ſeemingly different from every other metal, but not yet ſufficiently examined.

An acid conjoined to the calx ponderoſa (ponderous calx or lime) is nearly allied to the preceding, but dropped into lime water produces a different compound, though in a number of other circumſtances theſe two acids agree. I apprehend that this is likewiſe of a metallic nature.

Phoſphoric ACID, evidently exiſts in the animal kingdom,^[15] much more plentifully in the vegetable, but in the foſſil very rare. Mr. J. G. Gahn firſt detected it united with lead;^[16] but probably it may be found in many other foſſils. It is fuſible in the fire. Its ſpecific gravity when deprived of water 2,687.

Boracic ACID, (acid of borax, or ſedative ſalt.) Many people ſtill think this to be an artificial production, but not long ſince Mr. Hoefer^[17] found it in a lake near Sienna in the great dutchy of Hetruria, and it has long been known to be united to the foſſil alkaly in native borax. It acts like an acid, though very feebly. It melts in the fire and volatilizes with water. Its ſpecific gravity is 1,480.

Amber ACID, is a concrete ſalt obtained from amber; it acts like a feeble acid. It is yet doubtful whether amber be of vegetable origin; many reckon it foſſil.

Aerial ACID (fixed air) is not only combined with water but with many other foſſil ſubſtances, as alkalies (§§ 54, 56), earths (§§ 62, 66), and with ſome metals (§§ 71, 183, 192, 217, 234, 243). It floats uncombined in the atmoſphere. Its ſpecific gravity 0,0018^[18].

ALKALIES are known by their peculiar lixivial taſte, by their vehement attraction to acids, and by their changing the blue colours of vegetables to a green. In a pure ſtate, as was before obſerved of acids, their attraction to other ſubſtances is ſo ſtrong that they cannot long remain uncombined; and if other acids were wanting, the aerial acid, every where preſent in the atmoſphere, would unite with them: therefore they are always found in a ſtate of combination, unleſs prepared by art.

New acids are daily detected, but no additions have been made to the three ſpecies of alkaly long ſince known.

Vegetable fixed ALKALY, deprived of every acid is not found on the face of the earth; but it is ſometimes met with in combination with the 22vitriolic acid (§ 44) or the muriatic (§ 46), generally with the nitrous, (§ 45) rarely with the aerial (§ 54).

Foſſil fixed ALKALY is only found in combination with acids, rarely with the vitriolic (§ 47) or nitrous (§ 48), principally with the muriatic (§ 49) or aerial (§ 55).

Volatile ALKALY is frequently found in clays, doubtleſs in a mild ſtate, for the help of art is required to render it cauſtic. It is alſo found united to the vitriolic (§ 50) and the muriatic acids (§ 52.)

ACIDS united to alkalies form NEUTRAL SALTS. Theſe diſſolved in water are no ways diſturbed by the addition of an alkaly, and generally by evaporation concrete into cryſtals. If by proper teſts they ſhew neither acid nor alkaline properties they are ſaid to be perfect neutrals, but imperfect when from defect in quantity or ſtrength of one ingredient the peculiar properties of the other more or leſs prevail.

We now proceed to conſider the native ſalts of both kinds.

NEUTRAL SALTS.

Alkali vegetabile vitriolatum (tartar of vitriol) ſeldom occurs ſpontaneouſly, unleſs where tracts of wood have been burnt down.

Alkali vegetabile nitratum (common nitre) forms upon the ſurface of the earth where vegetables, eſpecially when mixed with animal ſubſtances, putrify. The alkaline baſis previously exiſts in the plants^[19], but the origin of the acid is not ſo well underſtood: whether it lies concealed in the vegetable acid, and by means of the putrefactive proceſs ſufficiently dephlogiſticating it, is evolved; or whether the purer part of the atmoſpheric air contains nitrous acid fully ſaturated with phlogiſton, which^[20] upon the alkaly being ſeparated by the putrefaction is attracted and extricated by it, and upon loſing its inflammable principle aſſumes its accuſtomed form. Nature perhaps operates in both ways; the latter however ſeems clearly confirmed by a very remarkable experiment (§ 60.)

24As nitre is annually produced in large quantities, it cannot but ſometimes be found in ſprings or wells, as has been obſerved at Berlin^[21], London^[22], and elſewhere^[23]. Sometimes it abounds in ſuch quantities that fleſh boiled in theſe waters turns red.

ALKALI vegetabile ſalitum (digeſtive ſalt) is ſometimes though rarely met with; generated perhaps by the deſtruction of animal and vegetable ſubſtances.

ALKALI minerale vitriolatum (Glauber’s ſalt) is ſometimes found in waters. Some of the lakes in Siberia and Astracan contain it, and many ſprings in other places.

ALKALI minerale nitratum (cubic nitre) rarely occurs but where maritime plants putrify.

ALKALI minerale ſalitum (common ſalt) plentiful every where as well in the earth, where it 25forms ſtrata more or leſs thick (ſal gem), as alſo diſſolved in ſprings and lakes, and in the ſea. (ſea ſalt.)

ALKALI volatile vitriolatum (vitriolic ammoniac) is ſcarcely found any where but in places where the phlogiſticated fumes of vitriolic acid ariſe from burning ſulphur, and in putrid places are abſorbed by the volatile alkaly.^[24] Thus at Fahlune the acid vapour from the roaſted minerals produces this ſalt in the neceſſary houſes. It is ſometimes alſo formed in the craters of volcanoes.

ALKALI volatile nitratum (nitrous ammoniac) is generally found along with common nitre.

ALKALI volatile ſalitum (ſal ammoniac or common ammoniac.) I have examined ſome from Veſuvius, and ſome from the Solfaterra near Naples.

26The ſalts hitherto enumerated are perfect neutrals, thoſe which follow are imperfect (§§ 53, 56.)

ALKALI FOSSIL, only in part ſaturated with a peculiar acid is called tinkal; after depuration, borax. It is dug out of the earth in the kingdom of Thibet^[25]. Borax takes nearly an equal weight of acid before the alkaline properties entirely diſappear^[26].

I believe no one has yet found the acid of borax united either to the vegetable or volatile alkalies.

ALKALI VEGETABILE aeratum (mild vegetable alkaly) is hardly ever found native, unleſs in the neighbourhood of woods deſtroyed by fire.

In the year 1774, at Douai in Flanders, a ſpring was diſcovered ſurrounded by a wall, whoſe waters, beſides other impregnations, contained 11 grains of vegetable alkaly in a pint^[27].

ALKALI MINERALE aeratum (mild foſſil alkaly, natron, the nitre of the ancients) is found plentifully in many places, particularly in Africa and Aſia, either concreted into chryſtallized ſtrata, or fallen to a powder; or effloreſcing on old brick walls, or laſtly, diſſolved in ſprings. It frequently originates from decompoſed common ſalt. I am not ignorant that the acid of common ſalt adheres ſtrongly to its baſis ſo as not to be expelled by fire; but perhaps the viciſſitudes of the atmoſphere continually acting for ages, may be more powerful. In immenſe plains covered over with this alkaly, ſcarcely any common ſalt is found upon the ſurface, but the deeper you dig the more it is contaminated by it, the common ſalt being yet undecompoſed for want of acceſs of air.

ALKALI VOLATILE aeratum (mild volatile alkaly) has been found in pump waters in London^[28], in Lauchſtadt^[29], at Frankfort on the Mayne^[30], and copper immerſed therein is ſaid to have been diſſolved into a blue liquor.

The three alkalies mentioned above as ſaturated with aerial acid, differ greatly from cauſtic alkalies, 28in the mildneſs of their taſte, in their property of chryſtallizing, and in their efferveſcing with acids which expel the aerial acid, but they ſtill change vegetable blues to greens, though not ſo powerfully as the cauſtic alkalies do. Therefore, although the ſubtil aerial acid in other reſpects gives them neutral properties, yet in this it does it but imperfectly.

The compounds of earths and acids which poſſeſs ſolubility mentioned at § 20, are decompoſed and precipitated by mild, but not by phlogiſticated alkalies.

TERRA PONDEROSA vitriolata, (heavy ſpar, marmor metallicum, calk) is placed with the earths (§ 89.) Terra ponderoſa nitrata i. e. terra ponderoſa united to the nitrous acid, perhaps exiſts ſomewhere, but has never been met with; neither has the terra ponderoſa united to the aerial acid, yet been found^[31]. Terra ponderoſa ſalita i. e. terra ponderoſa with the muriatic acid Mr. 29Hielm ſays^[32] is diſſolved in the waters of the lake Vettern and its neighbourhood.

CALX vitriolata (gypſum, ſelenite) is not only found diſſolved in various waters, but alſo in many places forms immenſe ſtrata. It is placed by all mineralogiſts amongſt the earths, but I think improperly. When burnt it generates heat with water, but in a leſs degree than lime does.

CALX nitrata (nitre of lime; terrene nitre) is ſometimes found in water, but very ſparingly. It is ſaid that the chalk hills in ſome parts of France become ſpontaneouſly impregnated with nitrous acid, which may be waſhed out, and after a certain time they will become impregnated with it again.

CALX Salita (fixed ammoniac) occurs very frequently in waters.

CALX aerata (marble, limeſtone, chalk, ſpar) is very commonly found diſſolved in waters in conſequence of an exceſs of the aerial acid. When it greatly abounds, the water is ſaid to be hard (cruda). By boiling, or by evaporation, it depoſits ſtreaks or cruſts of calcareous matter.

30Calx aerata is not ſoluble in water without an exceſs of the ſubtil acid, and therefore might properly be referred to the earths (§ 21).

MAGNESIA vitriolata (Epſom ſalt) is not unfrequent in the waters of England, Bohemia, and other countries. This ſalt is preſently decompoſed by lime water, which circumſtance readily diſtinguiſhes it from the alk. min. vitriol. or Glauber’s ſalt.

MAGNESIA nitrata (magneſia and nitrous acid) is uſually found together with nitre.

MAGNESIA ſalita (magneſia and muriatic acid) is found diſſolved in various waters, but plentifully in ſea water, to which it gives a diſagreeable bitterneſs.

MAGNESIA aerata (common magneſia) with an exceſs of aerial acid it becomes ſoluble in cold water, otherwiſe it is ſcarce ſoluble at all, and therefore ſhould be claſſed with the earths. (§ 21.)

ARGILLA vitriolata (alum) is ſometimes ſpontaneouſly generated by the decompoſition of pyrites lodged in clay, or in argillaceous ſchiſtus.

It is found in a ſpring at Steckenitz in Bohemia^[33], in Eaſt Bothnia and elſewhere. What is commonly called plumoſe alum is not a ſaline ſubſtance.

ARGILLA (clay) united to the nitrous, muriatic^[34], or aerial acids has not to my knowledge hitherto been found in any waters.

METALLIC SALTS.

The native ſalts belonging to this diviſion, may be diſtinguiſhed by the phlogiſticated alkaly which precipitates them all. The few which have ſaline properties (§ 20.) we ſhall mention here, referring the reſt to the mineralized metals.

CUPRUM vitriolatum (vitriol of copper, blue vitriol) is found in the mines of Herregrund, Fahlune, and others which contain copper pyrites.

FERRUM vitriolatum (vitriol of iron, green vitriol) is formed from the decompoſition of the more common pyrites.

FERRUM aeratum (iron with aerial acid) diſſolved by an exceſs of acid in the lighter chalybeate waters.

33FERRUM nitratum, and ſalitum (iron with nitrous and muriatic acids) have never yet been found native.

NICCOLUM vitriolatum (vitriol of Nickel) ſometimes exiſts from the decompoſition of ſulphureous ores of Nickel.

ZINCUM vitriolatum (vitriol of zinc, white vitriol) is ſometimes, though rarely, produced By the decompoſition of pſeudogalena, or black Jack, becauſe this ſubſtance does not very readily decompoſe ſpontaneouſly.

^[35]MANGANESIUM ſalitum (manganeſe united to muriatic acid) exiſts in ſome waters Mr. Hielm ſays.

Whether manganeſe be ever united to waters like iron, by means of an exceſs of aerial acid, we know not.

TRIPLE SALTS.

The compound ſalts hitherto enumerated are ſuch as are compoſed of two ingredients only; but ſometimes three or more are ſo united as not to be ſeparated by chryſtallization. The vitriols that we are acquainted with are hardly ever pure, and two or three of them ſometimes are joined together.

Sometimes likewiſe it happens that neutral ſalts join earthy ſalts, and earthy ſalts metallic ones. I generally diſtinguiſh compound ſalts according to the number of their principles, whether the ſame acid be joined to ſeveral baſes, or the ſame baſis to different acids; or laſtly, whether ſeveral menſtrua and ſeveral baſes are joined together. Hence ariſe ſalts triple, quadruple, &c. which the diligence of after times muſt illuſtrate. I ſubjoin the moſt remarkable examples of triple and quadruple native ſalts which have occurred to me.

ALKALI MINERALE Salitum (common ſalt) contaminated by magneſia ſalita. The common 35ſalt when pure does not deliqueſce, but this degree of purity is ſeldom found, and in the native foſſil production (ſal gem) never.

MAGNESIA vitriolata (Epſom ſalt) contaminated by ferrum vitriolatum^[36] (vitriol of iron.)

ARGILLA vitriolata (alum) native, contaminated by vitriol of iron. In the aluminous ſchiſtus it ſometimes effloreſces in a feathery form. Is this the plumoſe alum of the antients?

ARGILLA vitriolata (alum) native; contaminated by ſulphur and vitriolic acid.

At the places about Wedneſbury and Bilſton, in Staffordſhire, where the coal pits are on fire, this ſubſtance ſublimes to the ſurface, and may be collected in conſiderable quantity during dry or froſty weather. I cannot be certain that this is a true chemical union, but the eye cannot diſtinguiſh the parts. Perhaps the ſulphur volatilizes the alum and ſo becomes intimately mixed with it. The exceſs of vitriolic acid keeps it in a deliqueſcent ſtate.

I believe a ſimilar compound ſubſtance ſublimes at the Solfaterra near Naples. W.

ARGILLIA vitriolata (alum) native, contaminated by vitriol of cobalt. In the mines of Herregrund and Idra this may be ſeen, ſhooting out into long ſlender filaments. Perhaps this is the trichites of the Greeks. Diſſolved in water it immediately betrays the preſence of vitriolic acid, upon the addition of terra ponderoſa ſalita (muriatic acid ſaturated with heavy earth.) By the addition of phlogiſticated alkali a precipitate of cobalt is thrown down, which makes a blue glaſs with borax or microcoſmic ſalt.

CUPRUM vitriolatum (vitriol of copper) contaminated by iron.

FERRUM vitriolatum (vitriol of iron) contaminated by nickel.

CUPRUM vitriolatum (vitriol of copper) and vitriol of iron contaminated by zinc. Such is found at Fahlune.

CLASS II. EARTHS.

Before we can underſtand the nature of earths, we muſt know their component parts. Thoſe earths which cannot be further decompoſed we call primitive, and thoſe which conſiſt of two or more of theſe intimately united, derivative. By this union we do not mean a mere mechanical diffuſion, at leaſt not ſuch as can be diſtinguiſhed by the eye, as is the caſe in ſtones, (ſaxa.)

It is evident that the primitive earths will conſtitute ſo many natural Genera, and different mixtures of theſe the Species.

They who would make ſeveral Genera out of one primitive earth, muſt ſeparate the glaſſy, red, white, horny ſilver ores, and other different compoſitions into as many Genera, or elſe act inconſiſtently with their own principles.

At preſent we only know five primitive earths. They who reckon fewer, reſt their opinions upon fanciful metamorphoſes unſupported by faithful 38experiments^[37]. As experiments teach us that there are five primitive earths, it is evident that the Species ariſing from the mixture of theſe cannot exceed twenty-four, viz. 10 double (conſiſting of two earths) 6 triple, 3 quadruple, and the 5 primitive.

Although theſe different mixtures are poſſible, and probably do exiſt, they have not yet been all found. The natural compoſitions of acids with the earths, forming ſubſtances not ſoluble in 1000 times their weight of boiling water, and which may be called ſaline earths, muſt be added to the ſpecies, as they are certainly chemical combinations.

The primitive earths hitherto detected are,

And we muſt believe theſe to be primitive, until it ſhall appear by proper experiments that they may be ſeparated into others ſtill more ſimple, or changed into one another by art.

39Theſe are firſt to be conſidered in their greateſt ſimplicity and purity, although nature never preſents us with ſuch, nor can they even by art be rendered abſolutely free from all heterogeneous mixture. Water and aerial acid readily unite with the four firſt, and when expelled by fire, a little of the matter of heat is added, and remains until driven out by a more powerful attraction. But in this ſtate they poſſeſs a degree of purity not to be attained by any other known method. Therefore it is neceſſary to examine them when ſufficiently burnt in order to diſtinguiſh better what properties depend upon adhering heterogeneous matters.

HEAVY EARTH, OR TERRA PONDEROSA.

To obtain this as pure as poſſible, the ſpathum ponderoſum § 89 (heavy ſpar) muſt be reduced to a fine powder, and with equal parts of fixed alkaly and charcoal duſt roaſted for an hour in a covered crucible. Powder the maſs, and add nitrous or muriatic acid diluted until all efferveſcence ceaſes, and the liquor be ſenſibly acid. To this liquor add mild fixed alkaly, and the heavy earth will be precipitated in a mild ſtate. If the acids or the alkaline ſalt contain any vitriolic acid, the heavy ſpar will immediately be regenerated. What remains undiſſolved by the acid is heavy ſpar, not decompoſed. The proceſs may be repeated upon this, but the product will then contain ſome martial earth and ſome clay from the crucible, therefore the firſt part will be the moſt pure.

TERRA PONDEROSA aerata, (heavy earth) has a ſpecific gravity of 3, 773^[38]. 100 parts of it contain about 28 of water, 7 of aerial acid, and 65 of pure earth. It efferveſces with acids: with the vitriolic acid forms heavy ſpar, not ſoluble in water; with the nitrous and muriatic acids, it yields chryſtals, not very readily ſoluble; but with the vegetable acid the chryſtals deliqueſce.

When free from all contamination of acid or alkaly it ſcarcely melts in the fire, but loſes ³⁵⁄₁₀₀ of its weight. When united with the matter of heat, (i. e. rendered cauſtic) it diſſolves in 900 times its weight of water; and when this ſolution is expoſed to the atmoſphere, a cream or cruſt ſeparates at the top, which efferveſces with acids. After burning, it unites to acids without efferveſcence; but heat is produced, and the union is more tardy than when it is in a mild ſtate^[39].

When cauſtic, it expels the volatile alkaly from ſal ammoniac, and forms a hepar with ſulphur, the watery ſolution of which is but imperfectly decompoſed by the nitrous or muriatic acids, 42upon account of the remarkable attraction betwixt this earth and the acid of the ſulphur, which it even takes from the vegetable alkaly^[40].

When we compare theſe properties with thoſe which belong to common calcareous earth, mentioned at (§§ 92, 93), we ſhall readily ſee wherein they agree, and wherein they differ.

TERRA PONDEROSA vitriolata (heavy ſpar) is full four times as heavy as an equal bulk of water. It diſſolves entirely, though ſparingly, in concentrated boiling vitriolic acid, but the addition of a ſingle drop of water occaſions a precipitation. The ſame thing happens to gypſum; but that requires much leſs acid to diſſolve it, and the precipitation is made more ſlowly. If the heavy ſpar contained any ſulphur, it muſt certainly have appeared when the whole was diſſolved, but I never could find any thing like it.

Cronstedt, Min. § 18. 2.

Marmor metallicum druſicu § 19 C. Ponderous Spar.

TERRA PONDEROSA vitriolata, impregnated with bitumen, and mixed with gypſum, alum, and ſiliceous earth.

Cronstedt Min. § 24. Lapis hepaticus. Liver Stone.

43A nucleus of this kind, taken out of a piece of alum ore from Andrarum in the province of Skone, yielded, in 100 parts, by analyſis, 33 of ſiliceous earth, 29 of cauſtic heavy earth, earth of alum about 5, and quick-lime from 3 to 7, beſides the water and vitriolic acid. By calculation it appears, that theſe baſes, together with vitriolic acid enough to ſaturate them, ought to weigh 71, which, with the addition of 33, exceeds the amount of the original 100. This increaſe points out the difference of a maſs newly chryſtallized, and of one carefully dried.

When we conſider that the terra ponderoſa was altogether unknown before the year 1774, and that many mineralogiſts are even now unacquainted with it, we cannot wonder that we know ſo few ſpecies of it. I have ſcarce a doubt but the terra ponderoſa aerata may be found mixed with other earths in many ſpecimens, when they come to be examined by chemical means more accurately than they could be heretofore. (See notes to §§ 58 and 88.)

CALCAREOUS EARTH, OR CALX.

As calcareous earth united to the aerial acid is found native, it requires but little trouble to have it pure. Let ſelected pieces of chalk, reduced to fine powder, be repeatedly boiled in pure water: this diſſolves any calx or magneſia ſalita which it may contain. This done, it holds no heterogeneous matter but what mechanically adheres to it, the quantity of which is generally extremely ſmall. If we deſire to be free from this likewiſe, diſſolve the waſhed chalk in diſtilled vinegar, precipitate with volatile alkaly, and after waſhing the precipitate well, dry it.

The ſpecific gravity of calcareous earth thus purified, is 2,720. 100 parts of it contain about 34 of aerial acid, 11 of water, and 55 of pure earth.

Acids unite with it efferveſcing, and a centenary (centenarius) excites about 22 degrees of 45heat. The vitriolic acid forms gypſum, difficult to diſſolve, (§ 59). The nitrous and muriatic acids form deliqueſcent ſalts (§§ 60, 61), and the acetous acid permanent chryſtals.

Pure calcareous earth does not melt in the fire, but loſes ⁴⁵⁄₁₀₀ of its weight. It diſſolves in 700 times its weight of water, generating heat^[41]. Acids diſſolve it, producing from a centenary 252 degrees of heat, but without any efferveſcence. This laſt circumſtance may be beſt obſerved by immerging the burnt earth in water, to diſſipate a part of the heat, which would otherwiſe make the acid boil. The water likewiſe expels the atmoſpheric air from the pores of the lime. In this ſituation, if nitrous or muriatic acid be poured upon it, and if it was previouſly well burnt, no efferveſcence will take place. The ſolution proceeds ſlowly^[42], but the ſaturation becomes as perfect as if the calcareous earth had been in a mild ſtate. This burnt earth, or lime, expels the volatile alkaly from ſal ammoniac in a cauſtic ſtate, and it diſſolves ſulphur; but this compound is ſeparated upon the addition of any acid, even the aerial.

Amongſt the native Species of this genus, we muſt firſt mention the Calx aerata (marble, limeſtone, 46chalk) which conſtitute immenſe ſtrata. Its chief properties are enumerated above (§ 92). It is very rarely found entirely free from iron, which exiſts even in the pureſt Icelandic ſpar, and indeed in almoſt every foſſil production; upon which account only the more remarkable impregnations with iron will be noticed in the following pages.

Cronstedt Min. §§ 5–12.

CALX aerata (calcareous earth mild), with more or leſs petroleum. It efferveſces with acids, and diſſolves; with the vitriolic acid frequently turning brown. Is fœtid when heated or rubbed. The oil is not in ſufficient quantity to be collected, by diſtillation, in drops; it only fouls the inſide of the veſſels, unleſs a very great quantity be operated upon. In an open fire the colour preſently vaniſhes, from the petroleum drying up. It generally contains a portion of martial clay.

Cronstedt Min. §§ 22, 23. Lapis ſuillus. Fœtid ſtone.

CALX fluorata (calcareous earth and fluor acid), when pure, is wholly ſoluble in nitrous and muriatic acids. Expoſed to heat, below ignition, it emits a phosphoreſcent light. Fluor acid, dropped into lime water, precipitates a powder which 47has all the properties of the calx fluorata. It is ſometimes, but not always, contaminated by a ſmall proportion of ſiliceous earth and muriatic acid.

Cronstedt Min. §§ 97–101. Sparry fluor. Blue John.

CALX (calcareous earth) ſaturated with a peculiar acid, perhaps of a metallic nature (§ 33). In acids, particularly in the muriatic, it aſſumes a remarkable yellow colour, but is not very ſoluble.

Cronstedt Min. § 210. Lapis ponderoſus. Tungſten.

CALX aerata (calcareous earth mild), contaminated by a ſmall proportion of magneſia ſalita.

CALX aerata (calcareous earth mild) contaminated by clay.

CALX aerata (calcareous earth mild), contaminated by ſiliceous earth.

CALX aerata (calcareous earth mild), contaminated by clay and ſiliceous earth. (See § 115.)

Cronstedt Min. §§ 25. 28. Calcareous Marle.

CALX aerata (calcareous earth mild), contaminated by iron and manganeſe. Martial.

Cronstedt Min. §30. See alſo §203. Hæmatites.

There can be no doubt that the four firſt (§§ 94–97.), if not the laſt (§ 102), are genuine and diſtinct ſpecies; there is ſome difficulty as to the reſt, dependent, perhaps, only upon mechanical mixtures. If the heterogeneous matters can be diſcerned by the eye, we cannot heſitate to refer the ſubſtance to the ſaxa (ſtones); but in theſe the eye cannot diſcern them. Moreover, we know that the earths have a mutual attraction to each other, and form combinations more intimate than mechanical ones. Earth of alum, precipitated by a cauſtic alkali, and thrown into lime water, preſently loſes its pellucid and ſpongy texture, turns white, and condenſes, abſorbing the lime from the water, and forming an union not to be ſeparated but by chemical means.

49From theſe conſiderations, I dare not venture to exclude doubtful ſpecies.

We ſay a thing is contaminated by another, when the mixture is of the mechanical kind; but when things are joined by the ſtronger power of attraction, we ſay they are united.

MAGNESIA.

Magnesia, called in the diſpenſatories, and by apothecaries magneſia alba, is a precipitation from its union with vitriolic acid, called Epſom ſalt. If this earthy precipitate be wanted in the greatest degree of purity, the Epſom ſalt must be taken chryſtallized, and well depurated, diſſolved in distilled water, and precipitated by volatile alkaly. Let the liquor be boiled for a few minutes, in order that what is kept in ſolution by the aerial acid may ſubside.

Magneſia, thus obtained, has a ſpecific gravity of 2,155. 100 parts of it contain about 25 of aerial acid, 30 of water, and 45 of earth^[43]. It diſſolves in acids, with a violent efferveſcence, but without heat. It again forms Epſom ſalt, with the vitriolic acid; with the nitrous acid it chryſtallizes, but the chryſtals are deliqueſcent; with the muriatic and vegetable acids it does not chryſtallize, and after drying, greedily attracts moiſture from the atmoſphere.

51It does not melt in a moderate heat, but loſes ⁵⁵⁄₁₀₀ of its weight, and then has no attraction for water; diſſolves ſlowly, even in acids, and that without efferveſcence, but with ſome degree of heat. After calcination, it expels the volatile alkaly from ſal ammoniac, and unites to ſulphur, though very feebly.

MAGNESIA aerata (common magneſia) is never found native and unconnected, unleſs in waters, when it is diſſolved by an exceſs of aerial acid. (§ 66.)

MAGNESIA aerata (common magneſia) united with ſiliceous matter. This efferveſces with acids, and not unfrequently ſtrikes fire with ſteel.

MAGNESIA intimately united with ſiliceous matter. The ſoluble part is ſlowly taken up by acids, without efferveſcence.

Cronstedt Min. §§79–83. and perhaps § 102–105 alſo; but I have not yet ſubmitted the aſbeſti to the liquid analyſis.

MAGNESIA united to argillaceous, ſiliceous, and pyritical matters.

M. Monnet diſcovered this, and the next ſpecies.

MAGNESIA united to argillaceous, ſiliceous, and pyritical matters, and likewiſe contaminated by petroleum.

This ſpecies reſembles aluminous ſchiſtus, but upon examination is found to contain more magneſia than clay.

All the ſpecies, except the firſt, are more or leſs contaminated by iron, but they do not owe all their colour to this ſubſtance. The green colours altogether vaniſh during ignition, and leave only a white opake maſs.

ARGILLACEOUS EARTH, OR ARGILLA.

By earth of alum (argilla) I do not mean common clay, which is never free from ſiliceous matter, but a pure clay, unmixed, at leaſt, with any other earth. It may be readily obtained by diſſolving Roman or roach alum in diſtilled water, filtering, and precipitating by mild volatile alkaly.

The ſpecific gravity of this pure clay, or earth of alum, is 1,305. It diſſolves in acids, with a little efferveſcence. With the vitriolic acid it forms alum; with the nitrous, muriatic and vegetable acids, deliqueſcent ſalts.

When dry, it abſorbs water greedily, becomes ſoft, and, with a due quantity of water, gains ſuch a tenacity, that it may be moulded at pleaſure. This maſs contracts greatly in the fire, from whence ariſe numerous cracks; and with a due 54degree of heat, it becomes hard enough to ſtrike fire with ſteel. By this burning it loſes its glutinous tenacity, and the water is excluded by the approach of the particles; nor does it again aſſume its former properties, but by ſolution and precipitation.

It may be diſſolved in the dry way, by means of fixed alkaline ſalt, as well as in the liquid way, by acids. The vitriolic acid is better than the others for this purpoſe, becauſe more eaſily concentrated.

Earth of alum neither diſſolves ſulphur, nor decompoſes ſal ammoniac.

ARGILLA (argillaceous earth) united to ſiliceous matter only.

Cronstedt Min. §78. Argilla porcellana. Porcelain clay.

I never examined any clay which did not contain a large quantity of ſiliceous earth; generally more than half its weight^[44].

ARGILLA (argillaceous earth) united to ſiliceous and irony matter.

Cronstedt Min. §§ 87 and 90. Bole. Dye-earth.

ARGILLA (argillaceous earth) united to ſiliceous and calcareous matter.

Cronstedt Min. §25. Marga argillacea. Marle.

ARGILLA (argillaceous earth) united to ſiliceous earth and magneſia.

Cronstedt Min. §§ 84, 4. B. Terra lemnia.

Its component parts reſemble thoſe of talc, but differ in their proportions, and are alſo leſs intimately united.

ARGILLA (argillaceous earth) united to ſiliceous, calcareous, and magneſia earths.

Lithomarga.(^[45]) Cronstedt Min. § 84. A.

ARGILLA (argillaceous earth) contaminated by vegetable alkaly and ſulphur, or at leaſt by the acid of ſulphur.

Cronstedt Min. § 124. 2. b. Minera aluminis romani.

It certainly contains vitriolic acid^[46], and perhaps, alſo, a ſmall portion of ſulphur. The vegetable alkaly ſufficiently ſhews its volcanic origin.

ARGILLA (argillaceous earth) contaminated by ſiliceous matter, pyrites, and petroleum.

Cronstedt Min. § 124. 2. c. Schiſtus aluminaris^[47].

57§ 119.

ARGILLA (argillaceous earth) intimately united with leſs than half its weight of ſiliceous earth, and a ſmall quantity of mild calcareous earth.

Cronſtedt Min. §§ 43–48. Gemma.

The Gems ſuffer no change under the blowpipe, with foſſil fixed alkaly, but are diſſolved by microcoſmic ſalt and borax.

The tourmaline holds a kind of middle place betwixt the gems and the ſcherle. The colour, in all of them, is owing to iron.

ARGILLA (argillaceous earth) intimately united to half its weight of ſiliceous earth (or more), and a little mild calcareous earth. Scherle.

Cronſtedt Min. §§ 68–71. Granatus et Baſaltes, which I call Scherle.

The remote varieties of theſe are eaſily diſtinguiſhed, the near ones difficultly.

ARGILLA (argillaceous earth) looſely united to half its weight, or more, of ſiliceous earth, and a little calcareous earth.

Cronstedt Min. §§ 108–112. Zeolithus. Zeolite.

There is a great affinity betwixt this and Scherle; but in the zeolite, the component parts cohere ſo looſely, that acids attach and ſeparate them without their being previouſly treated with alkalies; but this is not the caſe with the ſcherles.

Zeolite, contaminated by magneſia, I have not yet examined.

ARGILLA (argillaceous earth) intimately united to a large proportion of ſiliceous earth, and a ſmall proportion of magneſia.

Cronstedt Min. §§ 93–96. Mica. Talcum. ^[48]Glimmer. Talc.

SILICEOUS EARTH, OR TERRA SILICEA.

This, like the other primitive earths, is ſeldom found pure. In order to have it ſo, reduce clear quartz chryſtals into powder; melt it with four times the weight of fixed alkaly; diſſolve the whole in water; precipitate by a large quantity of ſtrong acid; carefully waſh and dry the precipitate.

The acid muſt be uſed in a ſuperfluous quantity, that any other earths contained may be diſſolved.

The ſpecific gravity of this earth, is 1,975. The particles, when firſt precipitated, occupy, in water, at leaſt twelve times the ſpace that they do when dried; ſo that, when ſufficiently fine, they may remain ſuſpended therein; nay, when vehemently heated in a cloſe veſſel, they may be diſſolved. No acid, except that of fluor ſpar 60(§ 30) has any action upon this earth. Fixed alkalies unite with it in the liquid way, but in the dry way they ſeize it with great vehemence, and convert twice their weight of it into a permanent transparent glaſs. Such is its affinity to alkalies, that it imparts to clay, which is always loaded with it, the power of ſeparating ſome of the acid from nitre and common ſalt. When pure, it is refractory in the fire.

Although ſiliceous earth is not altogether ſimple, yet, in mineralogy, it muſt be conſidered as primitive, until deciſive experiments ſhew us from which of the preceding earths it is derived^[49].

TERRA SILICEA (ſiliceous earth) united to very ſmall quantities of calcareous and argillaceous earth.

Cronstedt Min. § 51. Quartzum. Quartz.

TERRA SILICEA (ſiliceous earth) united to argillaceous earth.

Cronstedt Min. § 58. Calcedonius. Chalcedony.

And perhaps the Opal. The Hydrophanus is only a variety of theſe.

61Whether the carnelian, and other ſiliceæ, of finer or coarſer texture, belong to this or the preceding ſpecies I cannot yet determine with certainty.

TERRA SILICEA (ſiliceous earth), united to an argillaceous and highly martial earth.

Cronstedt Min. §§ 64, 65. Jaſpis. Jaſper.

TERRA SILICEA (ſiliceous earth), loaded with martial earth.

Cronstedt Min. § 53.

This ſpecies is often called jaſper, but improperly, becauſe it contains no argillaceous earth.

TERRA SILICEA (ſiliceous earth), united to argillaceous and a ſmall quantity of calcareous earth.

Cronstedt Min. § 63. Petroſilex. Chert.

TERRA SILICEA (ſiliceous earth) united to argillaceous earth and a little magneſia.

Cronstedt Min. §66. Feldſpathum. Feld ſpat.

TERRA SILICEA (ſiliceous earth), united to magneſia, mild calcareous earth, fluor ſpar and alſo to the calxes of copper and iron. Chryſopraſius. I have not examined this, but inſert it upon the experiments of Mr. Achard.

To determine accurately the ſpecies of earths is the moſt difficult part of mineralogy, for innumerable analyſes yet remain to be made. But that which now ſeems intricate and obſcure will become plain and eaſy when experiments have been ſufficiently multiplied.

CLASS III. INFLAMMABLES, OR BITUMINA.

To this head we refer all foſſils containing phlogiſton in ſuch great abundance, that under proper management they are inflammable. The Genera are obviouſly very few, and accurately ſpeaking there is only one Genus. But ſince phlogiſton is so very ſubtle as not by itſelf to become the object of our ſenſes, it will perhaps be adviſeable to conſider its more ſimple combinations as Genera: this has long been done ſo far as reſpects the metals, by univerſal conſent.

SULPHUR.

This name may be given to any acid coagulated by phlogiſton into a ſolid form. If all metals conſist of certain radical acids ſaturated with phlogiſton, as is highly probable, and with reſpect to arſenic is indubitably proved; then metals ought to find a place here. But until this theory be eſtabliſhed by numerous experiments, we ſhall only rank under this head the compounds which have not a metallic nature.

PHLOGISTON ſaturated with vitriolic acid.

Cronstedt, Min. § 151. Common Brimſtone. Sulphur.

PHLOGISTON ſaturated with aerial acid.

Cronstedt Min. § 154. A. plumbago. Black-lead.

The true compoſition of this has been detected by Mr. Scheele.

PHLOGISTON united to the acid of vitriol and of molybdæna; or what amounts to the ſame, ſulphur joined to the acid of molybdæna.

Cronstedt Min. § 154. b. c. Molybdæna. Molybdæna.

The acid of molybdæna has never yet been obtained quite free from phlogiſton (§ 32). If this acid be of a metallic origin, molybdæna is a mineralized metallic ſubſtance, and ſhould be placed with the other minerals.

PETROLEUM.

Phlogiston occurs alſo in the foſſil kingdom, combined in an oily form; but many ſuppose this derived from the vegetable kingdom.

PETROLEUM pure and ſelected.

Cronstedt Min. §§ 147–150. Naptha. Rock oil.

PETROLEUM joined to argillaceous earth.

Cronstedt Min. §§ 157–160. Lithantrax. Pit Coal.

PETROLEUM united to acid of amber.

Cronstedt Min. §§ 133–146. Succinum. Amber.

Many contend that amber has a vegetable origin; but as the point is not very well determined; and as it is found amongſt foſſils, I ſtill retain it here.

Ambergriſe, according to the aſſertion of Mr. Aublett, is nothing more than the juice of a tree inſpiſſated by evaporation into a concrete form. This tree grows in Guyana, and is called Cuma, but has not been inveſtigated by any botaniſt. Pieces of this tree are ſaid to be carried down into the rivers by heavy rains, and the ſpecimens examined by Mr. Rouelle had the odour and principal qualities of amber^[50]. Rumphius, long ſince, mentioned a tree called Nanarium, whoſe juice reſembled amber^[51].

DIAMOND.

At firſt ſight I may ſeem to have acted erroneouſly, by ſeparating this from the other gems, and inſerting it here; but after due conſideration, I know not where to place it better. It has never yet been decompoſed by the liquid analyſis^[52]; and when expoſed to the fire in an open veſſel, it is wholly conſumed, burning with a lambent flame. This deflagration, though ſlow, ſhews decidedly its affinity to the inflammables: beſides, in the focus of a burning glaſs, it leaves traces of ſoot^[53]. When further experiments teach us better, I ſhall willingly correct my error.

CLASS IV. METALS.

I have before mentioned the great affinity betwixt metallic and inflammable ſubſtances (§ 133). Zinc and arſenic stand, as it were, upon the borders betwixt them; for these, in proper circumſtances, burn with a very evident flame. All the metallic ſubſtances contain phlogiſton, and when, to a certain degree, deprived of it, fall into a powder like an earth; but their attractions for phlogiſton are different. Moſt of them, when melted in a common way, and expoſed to the air, have an earthy cruſt formed upon the ſurface, which cannot again be reduced to metal without the addition of ſome inflammable matter. The baſe metals, eleven in number, have this property: but the noble metals, platina, gold and ſilver, are ſo firmly connected to the phlogiſton, that they never calcine under fuſion, however long continued; and after being changed into a calx in the liquid way, when melted in the fire, they re-aſſume their metallic form, without any other phlogiſton than what is contained in the matter of heat.

Quickſilver holds a kind of middle place; for, like the baſe metals, it may be calcined, though 70not readily; and like the noble ones, it may be reduced by heat alone.

I have placed each diviſion of the metals in the order of their specific gravities.

Thoſe metals, which are found in a perfect metallic ſtate, are called native; thoſe united to acids, or to ſulphur, are ſaid to be mineralized; and thoſe which are only deprived of their phlogiſton, calciform^[54].

AURUM, OR GOLD.

The ſpecific gravity of this metal, when pure, is 19,640. Aqua regia diſſolves it; but except the dephlogiſticated muriatic acid, and in certain circumſtances the nitrous, no ſimple acid acts upon it, unleſs it has been previouſly calcined^[56]. The quantity of phlogiſton neceſſarily taken away in the ſolution of 100 parts of gold, I eſtimate at about 394; whilſt the ſame quantity of ſilver, loſes by ſolution in the nitrous acid, 100^[57]. Gold retains the phlogiſton neceſſary to its metallic form, more obſtinately than any other metal, except, perhaps, platina. It melts and calcines in the focus of a burning glaſs at 1301 degrees of heat.

AURUM nativum (gold native) united to ſilver.

73I do not know that gold has ever yet been found perfectly pure.

AURUM nativum (gold native) united to copper.

AURUM nativum (gold native) united to ſilver and copper.

AURUM nativum (gold native) united to ſilver, copper, and iron.

AURUM (gold), mineralized by ſulphur, by means of iron.

Cronstedt Min; § 166. a. Pyrites aureus.

But ſome doubt may be made about the mineralization of gold^[58].

AURUM (gold) mineralized by ſulphur, together with ſilver, lead, and iron.

Minera aurifera Nagyayenſis.

I have not yet fully examined this^[59].

PLATINUM, OR PLATINA.

Its ſpecific gravity is 18,000^[60], when very pure. It diſſolves in aqua regia, and the loſs of phlogiſton during the ſolution, according to the experiments hitherto made may be expreſſed 76by 756. Beſides the muriatic acid, which when dephlogiſticated diſſolves every metal, no acid acts upon platina without it has undergone a previous calcination. It ſeems to retain its phlogiſton more obſtinately than any other metal. To melt it requires a heat greater than that at which iron melts.

PLATINA native united to iron. Native.

Cronstedt Min. § 179.

I believe it has never been found quite free from iron, but this can be ſeparated by art^[61].

ARGENTUM, OR SILVER.

Its ſpecific gravity is 10,552. The nitrous acid readily diſſolves it, the vitriolic muſt be boiling hot; the muriatic attracts its calx very ſtrongly, but cannot remove its phlogiſton and therefore cannot diſſolve it in its metallic ſtate. The quantity of this phlogiſton which cauſes the difference betwixt its metallic and its calciform ſtate I before expreſſed as 100 in 100 parts of ſilver. But the force with which it retains this portion of its phlogiſton is leſs than that of gold; that is, it occupies the third place in a ſeries of all the metals. It melts at 1000 degrees of heat.

ARGENTUM nativum (ſilver native) united to gold. Native.

ARGENTUM nativum (ſilver native), united to copper. Native.

ARGENTUM nativum (ſilver native), united both to gold and copper. Native.

ARGENTUM nativum (ſilver native), united to iron. Native.

ARGENTUM nativum (ſilver native), united to arſenic. Native.

The arſenic hardly exceeds ⁶⁄₁₀₀.

ARGENTUM nativum (ſilver native), united to antimony. Native.

When melted, it ſmokes but has no ſmell of arſenic.

ARGENTUM nativum (ſilver native), united to arſenic and iron. Native.

79The three metallic ingredients are nearly in equal proportions.

All the ſpecies hitherto mentioned have metallic properties and appearances. The contaminating matters are ſometimes extremely ſmall, but not to be neglected when they exceed ¹⁄₃₀₀ part of the maſs.

ARGENTUM (ſilver) mineralized by the vitriolic and muriatic acids. Hornlike.

Cronstedt Min. §177. Minera argenti cornea. Horn-ſilver.

Mr. Woulfe^[62], detected the preſence of the vitriolic acid. The ſilver ſeldom exceeds ⁷⁰⁄₁₀₀. I know not whether it is ever altogether free from vitriolic acid.

ARGENTUM (ſilver), mineralized by the vitriolic and muriatic acids, and ſulphur.

I doubt whether this be a diſtinct ſpecies, ſince the ſulphur and the ſalts ſcarcely admit of any other than a mechanical union.

ARGENTUM (ſilver), mineralized by ſulphur. Glaſſy.

Cronstedt Min. § 169. Minera argenti vitrea.

It ſometimes contains ⁷³⁄₁₀₀ of ſilver, or more.

ARGENTUM (ſilver), mineralized by ſulphur and iron. Marcaſitical.

Cronstedt Min. § 176, 10. Pyrites argenteus.

ARGENTUM (ſilver), mineralized by ſulphur and lead. Potters.

Cronstedt Min. § 176, 8. Galena.

The ſilver is only a few half ounces in a hundred weight.

ARGENTUM (ſilver), mineralized by ſulphur and arſenic. Red.

Cronstedt Min. § 170. Minera argenti rubra.

81It contains about ⁷⁰⁄₁₀₀ of ſilver. Iron is frequently preſent, as in moſt other ſpecies but not always.

ARGENTUM (ſilver), mineralized by ſulphur, arſenic, and iron. Glittering.

Cronstedt Min. § 172.

I have examined ſome ſpecimens from Saxony which ſometimes contain no ſilver. May we not therefore ſuppoſe that the ſilver is native and not mineralized?

ARGENTUM (ſilver), mineralized by ſulphur, arſenic, iron and cobalt.

The ſilver is ſometimes more than ⁵⁰⁄₁₀₀.

ARGENTUM (ſilver), mineralized by ſulphur, arſenic, copper and iron. White ore.

Cronstedt Min. § 171. Minera argenti alba.

The proportion of ſilver varies much, ſometimes it is ¹⁰⁄₁₀₀ or more.

ARGENTUM (ſilver), mineralized by ſulphur, arſenic, copper, iron, and antimony. Grey ore.

Cronstedt Min. § 173. 6. Minera argenti griſea. In the province of Dal^[63].

It contains ²⁴⁄₁₀₀ of copper, ſeldom ⁵⁄₁₀₀ ſilver.

ARGENTUM (ſilver), mineralized by ſulphur, arſenic, antimony and iron. Plumoſe.

Cronstedt Min. §173. 5. Federertz of the Germans^[64].

It ſeldom contains more than a few half ounces of ſilver in the hundred weight.

It is abſurd to found ſpecies upon the differences of the matrix: theſe ought to be conſidered elſewhere.

HYDRARGYRUM, OR QUICKSILVER.

Its ſpecific gravity is 14,110. It has been erroneouſly ranked among the brittle metals, for at 654 degrees below 0 it freezes^[65], and then ſpreads under the hammer like lead. But as ſuch an extreme degree of cold rarely happens unleſs artificially produced, we ceaſe to wonder why it is always liquid or rather melted.

Nitrous acid diſſolves it readily, vitriolic acid requires to be aſſiſted by a boiling heat; muriatic acid does not act upon it all, unleſs previouſly deprived of as much phlogiſton as in 100 parts may be called 74. The attractive power wherewith it retains this portion of phlogiſton occupies the fourth place in the ſeries; that is, it holds it leſs ſtrongly than the noble but more ſtrongly than the baſe metals.

HYDRARGYRUM nativum (quickſilver native). Native.

Cronstedt Min. § 217.

Whether it be entirely free from every metallic contamination I have not yet tried.

HYDRARGYRUM (quickſilver), united to ſilver. Amalgamated.

Cronstedt Min. § 217.

HYDRARGYRUM (quickſilver), mineralized by muriatic and vitriolic acids. Hornlike.

Mineralogy owes the diſcovery of this to Mr. Woulfe. Phil. Tranſ.

HYDRARGYRUM (quickſilver), mineralized by ſulphur. Cinnabarine.

Cronstedt Min. § 218. Cinnabaris.

HYDRARGYRUM (quickſilver), mineralized by ſulphur and iron. Martial.

I am doubtful whether this be a diſtinct ſpecies. The iron perhaps is only mechanically diffuſed.

HYDRARGYRUM (quickſilver), mineralized by ſulphur and copper. Cuprous.

Cronstedt Min. § 219.

PLUMBUM , OR LEAD .

Its ſpecific gravity is 11,352, greater than that of any other of the baſe metals. The nitrous acid perfectly diſſolves it; the muriatic more difficultly; the vitriolic hardly at all, for the vitriol of lead being inſoluble in water incruſts the metal, and prevents its ſolution. After calcination the weakeſt vegetable acids diſſolves it, and acquire a ſweet taſte. The phlogiſton neceſſary to be taken away in order that it may diſſolve may be called 43, which is leſs than that of any other metal. Hence we underſtand why the calx of lead may be reduced with a very minute quantity of inflammable matter. With reſpect to the force wherewith it retains this phlogiſton it occupies the tenth place. It melts at 595 degrees of heat.

PLUMBUM nativum (lead), though many mineralogiſts doubt whether it has ever yet been found. Native.

PLUMBUM (lead), mineralized by vitriolic acid. Vitriol of.

Originating from the decompoſition of Galena. It is rarely met with. It was firſt obſerved by Mr. Monnet. It does not efferveſce with acids. It may be reduced by the blowpipe upon charcoal.

PLUMBUM (lead), mineralized by vitriolic acid and iron.

Exiſting in immenſe quantity in the iſland of Angleſea. It does not reduce with the blowpipe upon charcoal, but melts to a black glaſs^[66]. W.

PLUMBUM (lead), mineralized by the acid of phoſphorus. Phoſphorated.

This was diſcovered by Mr. Gahn. It does not efferveſce with acids. It melts upon charcoal with the blowpipe, but is not perfectly reduced.

PLUMBUM (lead), mineralized by the aerial acid. Aerated.

Cronstedt Min. § 185.

It efferveſces with acids, and is readily reduced upon charcoal^[67].

PLUMBUM (lead), mineralized by ſulphur. Sulphurated.

Cronstedt Min. § 187.

PLUMBUM (lead), mineralized by ſulphur and ſilver. Galena.

Cronstedt Min. § 188.

PLUMBUM (lead), mineralized ſulphur, with ſilver and iron.

Cronstedt Min. § 189.

PLUMBUM (lead), mineralized by ſulphur, with ſilver and antimony. Radiated.

Cronstedt Min. § 190.

CUPRUM , OR COPPER .

Its ſpecific gravity is 8,876. Nitrous acid diſſolve it readily, muriatic acid ſlowly, and the vitriolic requires intenſe boiling. The phlogiſton, ſeparated in the ſolution of 100 parts, may be expreſſed by 312. The weakeſt vegetable acids act upon it, eſpecially after calcination, and ſo do alkalies, the volatile alkaly eſpecially. With reſpect to the power with which it retains the phlogiſton, copper holds the eighth place. It melts with 1450 degrees of heat.

CUPRUM nativum (copper native). Native.

Cronstedt Min. § 193.

It’s rarely found without ſome alloy of gold, ſilver or iron; but I have not yet fully examined it.

CUPRUM calciforme (copper), ſimply deprived of its phlogiſton. Calciform.

Cronstedt Min. § 195.

CUPRUM (copper), mineralized by muriatic acid and argillaceous earth. Micaceous.

Mr. Werner, in his tranſlation of Cronſtedt’s Mineralogy, part 1, page 217, has deſcribed it accurately, and kindly ſent me a ſpecimen of it, which I analyſed^[68].

CUPRUM (copper), mineralized by the aerial acid. Aerated.

Cronstedt Min. §§ 194, 196. b. 3.

Mr. Fontana firſt pointed out its true compoſition. It contains about ⅔ of copper, ⅓ or ¼ of aerial acid, and a little water^[69].

CUPRUM (copper), mineralized by ſulphur. Vitreous.

Cronstedt, Min. § 197. Minera cupri vitrea; a common, but improper name.

It generally contains ſome alloy of iron.

CUPRUM (copper), mineralized by ſulphur, and a ſmall proportion of iron.

Cronstedt Min. § 198, b. Minera cupri lazurea.

By a ſmall proportion of iron, I mean leſs than the weight of the copper; by a large proportion, more. This contains from 40 to 50 per cent. of copper.

CUPRUM (copper), mineralized by ſulphur, and a large proportion of iron. Pyritical.

Cronstedt Min. § 198. Pyrites Cupri.

The quantity of copper varies greatly, but ſeldom exceeds ⁴⁰⁄₁₀₀.

CUPRUM (copper), mineralized by ſulphur, iron and arſenic. Grey.

Cronstedt Min. § 198. a. Pyrites cupri griſeus.

This frequently contains an alloy of ſilver. The copper rarely exceeds ⁶⁰⁄₁₀₀.

FERRUM , OR IRON .

Its ſpecific gravity is 7,800. All the acids readily diſſolve it; but the vitriolic muſt be diluted, otherwiſe it may be boiled almoſt to dryneſs, without effecting it. The phlogiſton, diſlodged from centenary of ductile iron, may, as experiments now ſtand, be called 342; and this is ſo feebly retained, that this metal, with a few others, holds the eleventh, or loweſt place in the ſeries.

It requires an intenſe degree of heat to fuſe it, viz. 1601, if the uſual compariſon betwixt the mercurial thermometer, and the metallic one of Mortimer, be true. Iron is red hot at 1050 degrees of heat.

FERRUM nativum (iron) native. Native.

95It can hardly be doubted, but that the great maſs of iron, brought by Pallas, from Siberia, into Europe, is the product of nature. Its compoſition reſembles that of forged iron; for 100 parts of it yield, by means of the muriatic acid, 49 cubic inches of inflammable air; and from many experiments upon ductile iron, that is found to yield from 48 to 51^[70].

FERRUM nativum (iron) native, united to arſenic. Arſenical.

Cronstedt Min. § 243. B. Miſspickel.

FERRUM (iron), with the power of attracting other iron. Loadſtone.

Cronstedt Min. § 211. b. Magnes.

The cauſe of this property is yet unknown.

FERRUM (iron), with phlogiſton enough to render it magnetic. Magnetic.

Cronstedt Min. §§ 212, 213.

96But the quantity of phlogiſton is far ſhort of that which is neceſſary to render it ductile, for a centenary hardly contains more than three cubic inches of inflammable air.

FERRUM calciforme (iron calciform), ſimply deprived of phlogiſton. Ochrous.

Cronstedt Min. §§ 202–206. Bloodſtone.

FERRUM (iron), mineralized by aerial acid, calcareous earth, and manganeſe. White.

Cronstedt Min. § 20. Minera ferri alba.

FERRUM (iron), mineralized by ſulphur. Pyritical.

Cronstedt Min. § 152. Pyrites.

FERRUM (iron) intimately united to a new brittle metal^[71], or to a peculiar modification of iron, rendering it brittle when cold. Cold-ſhort.

In cold-ſhort iron, a brittle metal exiſts, readily uniting to ductile iron, by the aſſiſtance of heat, but rendering it brittle when cold. This ſubſtance, diſſolved in acids, forms Pruſſian blue with phlogiſticated alkaly, but it is not magnetic: it 97affords a white calx, richer in phlogiſton than the yellow calx of good iron.

I hope, by more experiments, ſoon to become better acquainted with it.

FERRUM calciforme (iron calciform), phlogiſticated in a peculiar manner. Blue.

Cronstedt Min. § 208. Cæruleum Berolinenſe nativum.

Clay and mould are sometimes coloured ſuperficially by a dilute blue, and ſometimes the former, when newly dug up, is found to acquire this colour upon expoſure to the air. It is evident that the baſis of this colour is an irony matter, full of phlogiſton; for, by ignition upon a charcoal fire, it flames, turns red, and becomes magnetic. With a gentle heat it becomes green, but when melted gives black ſcoriæ.

Alkalies, as well as acids, diſſolve it, and the colour vaniſhes, but appears again, if precipitated from the former by acids, and from the latter by alkalies; but it has then a greenish caſt, and ſoon becomes white. This white ſediment, immerſed in an infuſion of galls, or of tea, recovers its former colour.

From what has been ſaid, it appears that this colour, although analogous to the artificial Pruſſian blue, differs from it in its intensity, in the mode of its production, and in various properties. It keeps its colour in water, but turns black with oil.

STANNUM , OR TIN .

Its ſpecific gravity is 7,264. Vitriolic, muriatic, acetous acids, and aqua regia, diſſolve it, but the nitrous, eſpecially when ſtrong, attacks it ſo violently, that it ſoon reduces it to the ſtate of an inſoluble calx.

The quantity of phlogiſton it loſes by ſolution, may be called 114; and this it retains with a force that gives it the ninth place in the ſeries. It melts eaſier than any metal, except quickſilver, viz. at 415 degrees.

STANNUM nativum (tin). Native.

This I have not ſeen. Some doubts are entertained of its true nature, and, perhaps, not without reaſon.

STANNUM ſulphuratum (tin), mineralized by ſulphur. Sulphurated.

[See the Preface.]

STANNUM calciforme (tin) calciform, contaminated by iron. Calciform.

VISMUTUM , OR BISMUTH .

The heaviest of all the brittle metals that follow it, its ſpecific gravity being 9,670. Nitrous acid, and aqua regia diſſolve it perfectly. The vitriolic acid muſt be boiled nearly to dryneſs before it acts upon it, and the muriatic acid only attacks its calx. The quantity of phlogiſton which reſists the action of menſtrua, is expreſſed by 57; and its power of retaining it ranks it in the ſeventh place. It melts at the heat of 494 degrees.

VISMUTUM nativum (biſmuth). Native.

Cronstedt Min. § 222.

VISMUTUM calciforme (biſmuth). Calciform.

Cronstedt Min. § 223.

101I am not able to ſay whether this is merely deprived of its phlogiſton, or whether it is not alſo mineralized by aerial acid.

VISMUTUM (biſmuth) mineralized by ſulphur. Sulphurated.

Cronstedt Min. § 224.

VISMUTUM (biſmuth) mineralized by ſulphur and iron. Pyritical.

Cronstedt Min. § 225.

NICCOLUM , OR NICKEL .

The regulus, when depurated, has a ſpecific gravity of 9,000, or more; but the common regulus, obtained by the firſt reduction, little exceeds 7,000. Aqua regia, and nitrous acid, diſſolve it perfectly; muriatic acid, ſlowly; vitriolic acid, not without boiling almoſt to dryneſs and the acetous acid does not act upon it, unleſs in a calciform ſtate. The quantity of phlogiſton ſeparated by ſolution, may be called 156; and this it retains with a force about equal to that with which iron retains its phlogiſton (§ 197).

The heat neceſſary to melt it, is about equal to that which gold requires; but when depurated, it is almoſt as difficult to melt as iron.

The properties of it are more fully examined elſewhere^[72].

NICCOLUM nativum (nickel) native, united to iron and arſenic. Native.

It ſometimes, perhaps, contains cobalt. As it contains neither ſulphur nor mineralizing acid, and is perfectly in its metallic form, it muſt be called native, although joined to other metals.

NICCOLUM aeratum (nickel) mineralized by aerial acid. Aerated.

Cronstedt Min. § 255.

NICCOLUM (nickel) mineralized by ſulphur, arſenic, cobalt, and iron. Mineralized.

Cronstedt Min. § 256. Cuprum Nicolai. Kupfer nickel.

ARSENICUM , OR ARSENIC .

The ſpecific gravity of the radical acid, is 3,391; of white arſenic, 3,706; of its glaſſy ſtate, 5,000; and its regulus, 8,308. Aqua regia, and muriatic acid, diſſolve it perfectly; the vitriolic acid requires boiling; the acetous acts only upon its calx: the nitrous acid not only takes away as much phlogiſton as may be expreſſed by 109, deprived of which the regulus is reduced to the ſtate of a calx, but in a large quantity, aſſiſted by a proper degree of heat, it at length so far dephlogiſticates this calx, as to leave the acid of arſenic alone. Theſe phænomena are well worthy of obſervation, as they ſeem to lay open the nature of metals in general. From analogy, it is probable that every metal contains a radical acid of a peculiar nature, which, with a certain quantity of phlogiſton, is coagulated into a metallic calx; but with a larger quantity, ſufficient to ſaturate it, forms a compleat metal. The radical acid retains the coagulating phlogiſton much more 105ſtrongly than that which is neceſſary to the ſaturation. But different metallic acids retain both with different degrees of attraction. Hence the noble metals cannot be calcined in the dry way; it is only by acid menſtrua that they can be brought into that form; but all the others loſe their ſaturating phlogiſton in the fire, though with more or leſs difficulty. I have diſtinctly obſerved eleven different degrees of reſiſtance: thus, gold may be precipitated by all the other metals, except perhaps platina, which I think may thus be explained. The calx of gold having the greateſt attraction for phlogiſton, takes it from all other metals, and thus loſing its ſolubility falls down in a metallic ſtate. Therefore gold in the ſeries of metals, occupies at leaſt the ſecond place. Platina is precipitated by all, but leſs evidently than gold. To this therefore, I think we muſt give the firſt place, and so on of the others as I have remarked in the character of each metal. As nickel, cobalt, iron, manganeſe and zinc, do not precipitate one another, they are put together in the laſt and eleventh place^[73].

In order to obtain the radical acids we muſt ſeparate them from the coagulating phlogiſton. If the induſtry of chemiſts ever effects this, I am confident that metallurgy will be wonderfully elucidated. This therefore is a taſk to which 106our labours muſt be directed. I know that analogy muſt be cautiously trusted, but it at leaſt leads us to new experiments. Hitherto this operation has only ſucceeded with arſenic; and it is worth notice, that this metal which holds the fifth place with reſpect to its quantity of phlogiſton, ſhould be inferior to all others with regard to the attraction by which the coagulating quantity is retained.

Arſenic melts, but the moment it ſuffers heat enough to melt it, it volatilizes, unleſs it be firſt calcined. The regulus thrown upon a plate of iron properly heated, preſently takes fire and calcines, diffuſing a ſmell like garlic^[74].

ARSENICUM nativum (arſenic), native, united to iron. Native.

Cronstedt Min. § 239.

I have never found it free from martial impregnation.

ARSENICUM nativum (arſenic), native, united to ſilver.

ARSENICUM calciforme (arſenic), deprived of phlogiſton. Calciform.

Cronstedt Min. § 240.

ARSENICUM (arſenic), mineralized by ſulphur. Yellow.

Cronstedt Min. § 241. Auripigmentum. Riſigallum.

ARSENICUM (arſenic), mineralized by ſulphur and iron. Pyritical.

Cronstedt Min. § 243. A. Pyrites arſenicalis.

COBALTUM , OR COBALT .

Its ſpecific gravity is 7,700. Nitrous acid and aqua regia readily diſſolve it. The vitriolic acid requires to be boiled nearly to dryneſs. The muriatic and acetous acids do not act upon it unleſs previouſly calcined. 270 expreſſes the quantity of ſaturating phlogiſton, which it retains with the ſame force that iron does. Common regulus melts in the ſame heat that copper does, but when well purified it is hardly eaſier to melt than iron.

COBALTUM nativum (cobalt), native and united to arſenic. Native.

Cronstedt Min. § 249.

COBALTUM calciforme (cobalt). Calciform.

Cronstedt Min. § 247.

It is found variouſly mixed, principally with arſenic, iron and copper, but whether mechanically or by a more intimate union I know not.

COBALTUM (cobalt), mineralized by acid of arſenic. Red.

Cronstedt Min. § 248.

The ſmall ſpecimens that I have been able to examine point out ſuch a compoſition^[75].

COBALTUM (cobalt), contaminated by iron and vitriolic acid. Vitriolic.

Cronstedt Min. § 250.

COBALTUM (cobalt), mineralized by ſulphur, arſenic and iron. Glanz-cobalt.

Cronstedt Min. § 251.

COBALTUM (cobalt), mineralized by ſulphur, arſenic, iron and nickel. Kupfernickel.

Cronstedt Min. § 252.

ZINCUM OR ZINC .

Its ſpecific gravity is 6,862. All the acids diſſolve it readily and with efferveſcence, which denotes its very lax union with the inflammable principle, as was remarked before (§ 219). 182 expreſſes the quantity of phlogiſton it loſes in ſolution. It melts in a heat of 699 degrees; and if the heat be a little increaſed it takes fire; and diſſipates in white flowers^[76].

ZINCUM calciforme (zinc), calciform ſimply deprived of its phlogiſton. Calciform.

Cronstedt Min. § 228. A. Lapis calaminaris.

It is almost always mixed with clay or calciform iron.

ZINCUM (zinc), mineralized by aerial acid. Aerated.

Cronstedt Min. § 228. A. 1.

ZINCUM (zinc) with aerial acid and mixed with ſiliceous matter. Siliceous.

D. A. Born ſent me chryſtals of this ſpecies, which expoſed to the fire gave out aerial acid, but they were not wholly ſoluble in acids.

ZINCUM (zinc), mineralized by ſulphur and iron. Black jack.

Cronstedt Min. §§ 229. 230. Pſeudogalena.

ANTIMONIUM OR ANTIMONY .

Its ſpecific gravity is 6,860. Aqua regia diſſolves it well; vitriolic acid requires boiling; muriatic and acetous acids act hardly at all upon it, unleſs previouſly calcined. The nitrous acid corrodes it ſo as to prevent the ſolution. The phlogiſton it loſes in ſolution is expreſſed by 120, and with reſpect to the force wherewith it retains this, it ſtands in the ſixth place. It melts at a heat of 809 degrees.

ANTIMONIUM nativum (antimony). Native.

Cronstedt Min. § 238.

ANTIMONIUM (antimony), mineralized by ſulphur. Sulphurated.

Cronstedt Min. § 234.

ANTIMONIUM (antimony) mineralized by ſulphur and arſenic. Red.

Cronstedt Min. § 235.

MANGANESIUM , OR MANGANESE .

Its ſpecific gravity is 6,850. This new metal is ſoluble in all the acids, and is ſo readily deprived of its ſaturating phlogiſton that with iron and ſome others it ſtands the loweſt in the ſeries. 227 expreſſes the quantity of phlogiſton it loſes in ſolution. It is very difficult to melt, more ſo than iron.

MANGANESIUM calciforme (manganeſe) ſimply deprived of phlogiſton. Calciform.

Cronstedt Min. § 114.

MANGANESIUM (manganeſe) mineralized by aerial acid.

Cronstedt Min. § 115. 1. a.

APPENDIX THE FIRST. — Salts with Salts. — Salts with Earths. — Salts with Inflammables. — Salts with Metals. — Earths with Earths. — Earths with Inflammables. — Earths with Metals. — Inflammables with Inflammables. — Inflammables with Metals. — Metals with Metals. — Salts with Earths and Inflammables. — Salts with Earths and Metals. — Salts with Inflammables and Metals. — Earths with Inflammables and Metals. — Salts with Earths, Inflammables, and Metals.

In the preceding pages only the more ſimple combinations occur, whoſe principles are either chemically united or at leaſt ſo ſubtly interwoven that the texture appears perfectly homogeneous. But if two or more of theſe ſpecies, forming little diſtinct maſſes are cemented together, theſe mechanical mixtures, diſcernible by the eye ought to conſtitute a new ſeries, to be diſtinguiſhed by their component parts as the others were by their firſt principles or chemical elements. Such compoſitions may well be excluded from the preſent work, but upon account of their extenſive phyſical, œconomical and metallurgical uſes, I propoſe to give a ſlight ſketch of them here, enumerating the more remarkable Genera.

In a general view it appears that not only ſeveral ſpecies cemented together may be referred to this place, but likewiſe thoſe which are mechanically diffuſed in a powdery or an earthy form.

From the laws of combination it is evident, that according to the arrangement of foſſils into four claſſes, there can be only TEN Genera compoſed of two, FOUR of three, and ONE of four conſtituent parts. And although ſo many have not yet been detected, yet it is better to mention them here as the induſtry of a future age will probably diſcover more. The ſpecies are formed from the differences of the more ſimple ſpecies and their component parts.

This compoſition can hardly ever conſtitute a genus, if it muſt be made in a dry and concrete form; for excepting gypſum, the other native ſalts readily diſſolve in water, and by evaporation are ſo mixed together as not readily to be diſcerned by the eye. Yet the foſſil alkaly mixed with common ſalt will perhaps find a place here. The contents of mineral waters may likewiſe be referred here, ſince every material difference in them depends upon the particles diſſolved.

This mixture is hardly to be found but where bits of gypſum are concreted to matters of an earthy nature.

May perhaps be found in volcanoes.

If gypſum forms the matrix of any metal, it muſt be placed here.

To this head belong moſt of the ſaxa (ſtones), enumerated by Mr. Cronſtedt, which form the immenſe bulk of mountains, and deſerve our particular attention, in order that, being better acquainted with the nature and ſtructure of the ſhell of the earth, we may be able to point out the coverings of minerals, and convert them all to our uſe.

Lumps of mountain pitch are frequently connected with ſtones, and ſulphureous matters are found diffuſed through earthy materials.

This genus contains the peculiar matrices of metals, a judicious conſideration of which would be particularly uſeful to miners.

Perhaps, in ſome places, ſulphureous matters are found mixed with mountain pitch.

If plumbago (black-lead) or common ſulphur, ſhall ever be found mixed with metallic ſubſtances, ſuch ſpecies muſt ſtand under this genus.

We know that ſome metals, in the boſom of the earth, are almoſt always mixed, whilſt others are rarely, or never, found together. A more accurate knowledge of theſe things, would illuſtrate phyſical geography, as well as metallurgy.

We now proceed to the more compound genera.

This genus can hardly ever occur but in countries formerly expoſed to ſubterranean fires.^[77]

To be expected amongſt volcanic productions.

To be ſought for in the productions of volcanoes.

Obvious amongſt the productions of volcanoes, otherwiſe extremely rare.

Hardly to be expected but in volcanic mountains.

APPENDIX THE SECOND. — Saline Calcareous Earth with an organic Form . — Saline Iron with an organic Form . — Mild Calcareous Earth with an organic Form . — Clay with an organic Form . — Siliceous Earth with an organic Form . — Earth organic. — Petroleum impregnating organic Bodies . — Silver with an organic Form . — Quickſilver in an organic Form . — Copper with an organic Form . — Iron with an organic Form . — Zinc with an organic Form .

Foſſils externally reſembling animals or vegetables, originate from foreign matters, which by ſome peculiar proceſs are changed in the boſom of the earth, or are ſo impregnated by mineral particles gradually occupying the place of thoſe which have putrified, that they no longer reſemble organic ſubſtances, except in figure.—Theſe are commonly called Petrefactions.

The harder ſhells of animals expoſed to the weather, are not always exempt from deſtruction; for their gelatinous matter being gradually deſtroyed by putrefaction, they become brittle, and in a manner calcined. In leſs expoſed ſituations, ſome of them preſerve the nature of their materials, but acquire a ſpar-like texture.

We muſt carefully diſtinguiſh betwixt the foreign bodies themſelves, changed or petrified, and their impreſſions upon the ſurrounding matrices. 123Sometimes the body is entirely deſtroyed, forming a cavity in the ſurrounding matter, and this cavity afterwards is filled with other materials. Nuclei, or kernels, are likewiſe found, formed within the cavities of the harder ſhells, and bearing the form of their internal ſurface.

I am far from thinking the knowledge of petrefactions is barren and uſeleſs. We may, and ought, to conſider them as medals depoſited by the hand of nature, in memory of the more remarkable changes on the ſurface of the earth, and from which the time and order of the work may, in ſome meaſure, be judged of, whilſt other monuments are ſilent. Theſe, being properly interpreted, ſhew us their native ſituations in the former ſtate of the ſurface of the earth, and teach us the unbounded empire of the ſea, and the conſequent changes. By them we learn to diſtinguiſh the ancient and modern foundations of the mineral kingdom; for thoſe which are not formed of petrefactions, and never contain them, are doubtleſs of greater antiquity than animals or vegetables; and, laſtly, by their figure they ſhew us the inhabitants of our globe, eſpecially thoſe of the greateſt depths of the ocean.

Mr. Cronstedt has admirably arranged the petrefactions; we think it right, therefore, to retain his method. The Genera are built upon the 124Genera of foſſils, and arranged like the four claſſes thereof; the ſpecies upon their ſpecies, and the varieties upon the organic ſubſtances that have been changed. The following are the Genera hitherto diſcovered.

Gypſeous petrefactions are very rare.

Human bodies have ſometimes been found indurated and penetrated by vitriol of iron; so likewiſe have plants, their roots eſpecially. In the open air they moulder away.

This conſtitutes the ſubſtance of moſt petrefactions.

It is remarkable, that petrefactions found in clay are compreſſed, although, in ſubjacent calcareous ſtrata, they preſerve their natural figure. Similar compreſſed petrefactions are alſo found in the marly ſchiſtus.

Siliceous petrefactions are ſometimes met with, but, in general, this material forms only nuclei (§ 264). Trunks of trees are ſometimes found changed into agate. The celebrated Ferber has ſeen petrefactions in chert and jaſper, and the illuſtrious Born mentions corallines (porpitæ) in ſinople or martial jaſper.

Animals and vegetables are reſolved by putrefaction into an earth, which may be regarded as forming a peculiar genus, until every appearance of organization being obliterated, at length it comes to be conſidered as common earth.

Wood, penetrated by indurated petroleum, forms a remarkable variety of coal.

Native ſilver is ſometimes inherent in petrefactions, but never, to my knowledge, conſtitutes the ſubſtance of them, unleſs mineralized with copper and ſulphur.

When mineralized by ſulphur, it ſometimes, though very rarely, conſtitutes petrefactions.

Bones and teeth are ſometimes found replete with the blue calx of copper. Bits of copper pyrites often ſtick in petrefactions, but ſeldom conſtitute their whole ſubſtance. I have some such from Norway, in a matrix of magnetical iron ore.

Calciform iron ſometimes is found in the ſhape of roots and branches of trees. When mineralized by ſulphur, it frequently exiſts in petrefactions, but ſeldom conſtitutes the whole maſs.

I have ſeen pſeudo-galena (black jack), in the form of coral.

Some modern writers, as well as Mr. Cronstedt, place the productions of volcanoes in an appendix by themſelves; but, I think, to no good purpoſe. Things formed by the hand of nature, whether by a liquid or a dry proceſs, muſt not be diſjoined; for ſhe frequently avails herſelf of both methods in one and the ſame inſtance. And, indeed, the origin of many things is ſo very doubtful, every veſtige thereof being obliterated, that even an Œdipus could not with certainty determine how they were produced. And, on the other hand, many aſſert, that almoſt the whole of the mineral kingdom is the product of fire. To 128avoid error, therefore, it is better to claſs foſſil ſubſtances according to their conſtituent parts, which proper experiments will lay open to us; for we can seldom know their origin or formation.

Homogeneous ſubſtances joined together, but not primitive, will find a place among the ſtones, or elſewhere, in the firſt appendix.

INDEX.

ERRATA.