copper; by a large proportion, more. This contains from 40 to 50 per
cent. of copper.
§ 195.
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.
§ 196.
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.
§ 197.
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.
§ 198.
FERRUM _nativum_ (iron) _native_. Native.
It 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].
§ 199.
FERRUM _nativum_ (iron) _native_, united to arſenic. Arſenical.
CRONSTEDT Min. § 243. B. _Miſspickel._
§ 200.
FERRUM (iron), with the power of attracting other iron. Loadſtone.
CRONSTEDT Min. § 211. b. _Magnes._
The cauſe of this property is yet unknown.
§ 201.
FERRUM (iron), with phlogiſton enough to render it magnetic. Magnetic.
CRONSTEDT Min. §§ 212, 213.
But 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.
§ 202.
FERRUM _calciforme_ (iron calciform), ſimply deprived of phlogiſton.
Ochrous.
CRONSTEDT Min. §§ 202–206. _Bloodſtone._
§ 203.
FERRUM (iron), mineralized by _aerial acid_, _calcareous earth_, and
_manganeſe_. White.
CRONSTEDT Min. § 20. _Minera ferri alba._
§ 204.
FERRUM (iron), mineralized by _ſulphur_. Pyritical.
CRONSTEDT Min. § 152. _Pyrites._
§ 205.
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 affords 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.
§ 206.
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.
§ 207.
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.
§ 208.
STANNUM _nativum_ (tin). Native.
This I have not ſeen. Some doubts are entertained of its true nature,
and, perhaps, not without reaſon.
§ 208*.
STANNUM _ſulphuratum_ (tin), mineralized by _ſulphur_. Sulphurated.
[See the Preface.]
§ 209.
STANNUM _calciforme_ (tin) calciform, contaminated by _iron_. Calciform.
VISMUTUM,
OR
BISMUTH.
§ 210.
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.
§ 211.
VISMUTUM _nativum_ (biſmuth). Native.
CRONSTEDT Min. § 222.
§ 212.
VISMUTUM _calciforme_ (biſmuth). Calciform.
CRONSTEDT Min. § 223.
I am not able to ſay whether this is merely deprived of its phlogiſton,
or whether it is not alſo mineralized by aerial acid.
§ 213.
VISMUTUM (biſmuth) mineralized by _ſulphur_. Sulphurated.
CRONSTEDT Min. § 224.
§ 214.
VISMUTUM (biſmuth) mineralized by _ſulphur_ and _iron_. Pyritical.
CRONSTEDT Min. § 225.
NICCOLUM,
OR
NICKEL.
§ 215.
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].
§ 216.
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.
§ 217.
NICCOLUM _aeratum_ (nickel) mineralized by _aerial acid_. Aerated.
CRONSTEDT Min. § 255.
§ 218.
NICCOLUM (nickel) mineralized by _ſulphur_, _arſenic_, _cobalt_, and
_iron_. Mineralized.
CRONSTEDT Min. § 256. Cuprum Nicolai. Kupfer nickel.
ARSENICUM,
OR
ARSENIC.
§ 219.
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
ſtrongly 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 our 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].
§ 220.
ARSENICUM _nativum_ (arſenic), native, united to iron. Native.
CRONSTEDT Min. § 239.
I have never found it free from martial impregnation.
§ 221.
ARSENICUM _nativum_ (arſenic), native, united to ſilver.
§ 222.
ARSENICUM _calciforme_ (arſenic), deprived of phlogiſton. Calciform.
CRONSTEDT Min. § 240.
§ 223.
ARSENICUM (arſenic), mineralized by _ſulphur_. Yellow.
CRONSTEDT Min. § 241. _Auripigmentum._ _Riſigallum._
§ 224.
ARSENICUM (arſenic), mineralized by _ſulphur_ and _iron_. Pyritical.
CRONSTEDT Min. § 243. A. _Pyrites arſenicalis._
COBALTUM,
OR
COBALT.
§ 225.
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.
§ 226.
COBALTUM _nativum_ (cobalt), native and united to _arſenic_. Native.
CRONSTEDT Min. § 249.
§ 227.
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.
§ 228.
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].
§ 229.
COBALTUM (cobalt), contaminated by _iron_ and _vitriolic acid_.
Vitriolic.
CRONSTEDT Min. § 250.
§ 230.
COBALTUM (cobalt), mineralized by _ſulphur_, _arſenic_ and _iron_.
Glanz-cobalt.
CRONSTEDT Min. § 251.
§ 231.
COBALTUM (cobalt), mineralized by _ſulphur_, _arſenic_, _iron_ and
_nickel_. Kupfernickel.
CRONSTEDT Min. § 252.
ZINCUM
OR
ZINC.
§ 232.
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].
§ 233.
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.
§ 234.
ZINCUM (zinc), mineralized by _aerial acid_. Aerated.
CRONSTEDT Min. § 228. A. 1.
§ 235.
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.
§ 236.
ZINCUM (zinc), mineralized by _ſulphur_ and _iron_. Black jack.
CRONSTEDT Min. §§ 229. 230. _Pſeudogalena._
ANTIMONIUM
OR
ANTIMONY.
§ 237.
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.
§ 238.
ANTIMONIUM _nativum_ (antimony). Native.
CRONSTEDT Min. § 238.
§ 239.
ANTIMONIUM (antimony), mineralized by ſulphur. Sulphurated.
CRONSTEDT Min. § 234.
§ 240.
ANTIMONIUM (antimony) mineralized by ſulphur and arſenic. Red.
CRONSTEDT Min. § 235.
MANGANESIUM,
OR
MANGANESE.
§ 241.
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.
§ 242.
MANGANESIUM _calciforme_ (manganeſe) ſimply deprived of phlogiſton.
Calciform.
CRONSTEDT Min. § 114.
§ 243.
MANGANESIUM (manganeſe) mineralized by _aerial acid_.
Aerated.
CRONSTEDT Min. § 115. 1. a.
APPENDIX
THE FIRST.
§ 244.
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.
§ 245.
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.
§246.
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.
Salts _with_ Salts.
§ 247.
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.
Salts _with_ Earths.
§ 248.
This mixture is hardly to be found but where bits of gypſum are
concreted to matters of an earthy nature.
Salts _with_ Inflammables.
§ 249.
May perhaps be found in volcanoes.
Salts _with_ Metals.
§ 250.
If gypſum forms the matrix of any metal, it muſt be placed here.
Earths _with_ Earths.
§ 251.
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.
Earths _with_ Inflammables.
§ 252.
Lumps of mountain pitch are frequently connected with ſtones, and
ſulphureous matters are found diffuſed through earthy materials.
Earths _with_ Metals.
§ 253.
This genus contains the peculiar _matrices_ of _metals_, a judicious
conſideration of which would be particularly uſeful to miners.
Inflammables _with_ Inflammables.
§ 254.
Perhaps, in ſome places, ſulphureous matters are found mixed with
mountain pitch.
Inflammables _with_ Metals.
§ 255.
If plumbago (black-lead) or common ſulphur, ſhall ever be found mixed
with metallic ſubſtances, ſuch ſpecies muſt ſtand under this genus.
Metals _with_ Metals.
§ 256.
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.
Salts _with_ Earths _and_ Inflammables.
§ 257.
This genus can hardly ever occur but in countries formerly expoſed to
ſubterranean fires.[77]
Salts _with_ Earths _and_ Metals.
§ 258.
To be expected amongſt volcanic productions.
Salts _with_ Inflammables _and_ Metals.
§259.
To be ſought for in the productions of volcanoes.
Earths _with_ Inflammables _and_ Metals.
§ 260.
Obvious amongſt the productions of volcanoes, otherwiſe extremely rare.
Salts _with_ Earths, Inflammables, _and_ Metals.
§ 261.
Hardly to be expected but in volcanic mountains.
APPENDIX
THE SECOND.
§ 262.
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.
§ 263.
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.
§ 264.
We muſt carefully diſtinguiſh betwixt the foreign bodies themſelves,
changed or petrified, and their impreſſions upon the ſurrounding
matrices. Sometimes 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.
§ 265.
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.
§ 266.
Mr. CRONSTEDT has admirably arranged the petrefactions; we think it
right, therefore, to retain his method. The Genera are built upon the
Genera 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.
_Saline Calcareous Earth_ with an _organic Form_.
§ 267.
Gypſeous petrefactions are very rare.
_Saline Iron_ with an _organic Form_.
§ 268.
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.
_Mild Calcareous Earth_ with an _organic Form_.
§ 269.
This conſtitutes the ſubſtance of moſt petrefactions.
_Clay_ with an _organic Form_.
§ 270.
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 Earth_ with an _organic Form_.
§ 271.
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.
_Earth organic._
§ 272.
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.
_Petroleum_ impregnating _organic Bodies_.
§ 273.
Wood, penetrated by indurated petroleum, forms a remarkable variety of
coal.
_Silver_ with an _organic Form_.
§ 274.
Native ſilver is ſometimes inherent in petrefactions, but never, to my
knowledge, conſtitutes the ſubſtance of them, unleſs mineralized with
copper and ſulphur.
_Quickſilver_ in an _organic Form_.
§ 275.
When mineralized by ſulphur, it ſometimes, though very rarely,
conſtitutes petrefactions.
_Copper_ with an _organic Form_.
§ 276.
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.
_Iron_ with an _organic Form_.
§ 277.
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.
_Zinc_ with an _organic Form_.
§ 278.
I have ſeen pſeudo-galena (black jack), in the form of coral.
§ 279.
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 avoid 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.
FINIS.
INDEX.
N. B. _The Numbers refer to the Sections._