By our former observations it appears that air is the necessary and
first food of fire, which can neither subsist nor propagate but by what
it assimilates, consumes, or carries off, of that element, whereas
of all material substances, air is that which seems to exist the
most independently of the aid or presence of fire; for although it
habitually has nearly the same heat as other matters on the surface
of the earth, it can do without it and requires infinitely less than
any of the rest to support its fluidity, since the most excessive cold
cannot deprive it of that. The strongest condensations are not capable
of breaking its spring; the active fire, in combustible matters, is the
only agent which can alter its nature by rarefying and extending its
spring to the point of rendering it ineffectual, and thus destroying
its elasticity. In this state, and in all the links which precede, the
air is capable of re-assuming its elasticity, in proportion as the
vapours of combustible matters evaporate and separate from it. But if
the spring have been totally weakened and extended that it cannot
re-instate itself, from having lost all its elastic power, the air,
volatile as it might before have been, becomes a fixed substance which
incorporates with the other substances, and forms a constituent part of
all those to which it unites by contact. Under this new form it can no
longer forsake the fire, except to unite, like fixed matter, to other
fixed matters; and if there remain some parts inseparable from fire,
they then make a portion of that element serve it for a base, and are
deposited with it in the substance they heat and penetrate together.
This effect is manifested in all calcinations, and is the more sensible
as the heat is longer; but combustion demands only a small time to
completely effectuate the same. If we wish to hasten calcination the
use of bellows may be necessary, not so much to augment the heat of the
fire as to establish a current of air on the surface of the matters;
yet it is not requisite for the fire to be very fierce to deprive air
of its elasticity, for a very moderate heat, when constantly applied
on a small quantity, is sufficient to destroy the spring; and for this
air, without spring, to fix itself afterwards in bodies, there is only
a little more or less time required, according to the affinity it may
have under this new form, with the matters to which it unites. The
heat of the body of animals, and even vegetables, is sufficiently
powerful to produce this effect. The degrees of heat are different in
different kinds of animals: birds are the hottest, from which we pass
successively to quadrupeds, man, cetaceous animals, reptiles, fish,
insects, and, lastly, to vegetables, whose heat is so trifling as to
have made some naturalists declare they had not any, although it is
very apparent, and in winter surpasses that of the atmosphere. I have
frequently observed in trees that were cut in cold weather, that their
internal part was sensibly warm, and that this heat remained for many
minutes. This heat is only moderate while the tree is young and sound,
but as soon as it grows old the heart heats by the fermentation of the
pith, which no longer circulates there with the same freedom; and as
soon as this heat begins the centre receives a red tint, which is the
first index of the perishing state of the tree, and the disorganization
of the wood. The reason naturalists have not found there was a
difference between the temperature of the air, and the heat of
vegetables is, because they have made their observations at a bad time
of the year, and not paid attention, that in the summer the heat of the
air exceeds that of the internal part of a tree; whereas in winter it
is quite the contrary. They have not remembered that the roots have
constantly the degree of heat which surrounds them, and that this heat
of the internal part of the earth is, during all winter, considerably
greater than that of the air, and the surface of the earth. They did
not consider that the motion alone of the pith, already warm, is a
necessary cause of heat, and that this motion, increasing by the action
of the sun, or by an external heat, that of vegetables must be so much
the greater as the motion of their pith is more accelerated, &c.
Here the air contributes to the animal and vital heat, as we have
seen that it does to the action of fire in combustible and calcinable
matters. Animals, which have lungs, and which consequently respire
the air, have more heat than those deprived of them; and the more
the internal surface of the lungs is extended, and ramified in a
greater number of cells, the more it presents greater superficies
to the air which the animal draws by inspiration; the more also its
blood becomes hotter, the more it communicates heat to all parts of
the body it nourishes, and this proportion takes place in all known
animals. Birds, relatively to the volume of their body, have lungs
considerably more extended than man or quadrupeds. Reptiles, even
those with a voice, as frogs, instead of lungs have a simple bladder.
Insects which have little or no blood breathe the air only by some
pipes, &c. Thus taking the degree of the temperature of the earth for
the term of comparison, I have observed that this heat being supposed
ten degrees, that of birds was nearly thirty-three, that of some
quadrupeds more than thirty-one and a half, that of man thirty and a
half, or thirty-one, whereas that of frogs is only fifteen or sixteen,
and that of fishes and insects only eleven or twelve, which is nearly
the same as that of vegetables. Thus the degree of heat in man and
animals depends on the force and extent of the lungs; these are the
bellows of the animal machine: the only difficulty is to conceive how
they carry the air on the fire which animates us, a fire whose focus
seems to be indeterminate; a fire that has not even been qualified
with this name, because it is without flame or any apparent smoke, and
its heat is only moderate and uniform. However, if we consider that
heat and fire are effects, and even elements of the same class; that
heat rarefies air, and, by extending its spring, it may render it
without effect; we may imagine, that the air drawn by our lungs being
greatly rarefied, loses its spring in the bronchiæ and little vesicles,
where it is soon destroyed by the arterial and venous blood, for these
blood-vessels are separated from the pulmonary vesicles by such thin
divisions that the air easily passes into the blood, where it produces
the same effect as upon common fire, because the heat of this blood
is more than sufficient to destroy the elasticity of the particles
of air, and to drag them under this new form into all the roads of
circulation. The fire of the animal body differs from common fire only
in more or less; the degree of heat is less, hence there is no flame,
because the vapours, which represent the smoke, have not heat enough
to inflame; every other effect is the same: the respiration of a young
animal absorbs as much air as the light of a candle, for if inclosed in
vessels of equal capacities, the animal dies in the same time as the
candle extinguishes: nothing can more evidently demonstrate that the
fire of the animal and that of the candle are not of the same class but
of the same nature, and to which the assistance of the air is equally
necessary.
Vegetables, and most insects, instead of lungs, have only aspiratory
tubes, by which they pump up the air that is necessary for them; it
passes in very sensible balls into the pith of the vine. This air
is not only pumped up by the roots but often even by the leaves,
and forms a very essential part of the food of the vegetable which
assimilates, fixes, and preserves it. Experience fully confirms all
we have advanced on this subject, and that all combustible matters
contain a considerable quantity of fixed air, as do also all animals
and vegetables, and all their parts, and the waste which proceeds
therefrom; and that the greatest number likewise include a certain
quantity of elastic air. And, notwithstanding the chimerical ideas
of some chemists, respecting phlogiston, there does not remain the
smallest doubt but that fire or light produces, with the assistance of
air, all the effects thereof.
Minerals, which like sulphur and pyrites, contain in their substance
a quantity of the ulterior waste of animals and vegetables, contain
thence combustible matters, which, like all other, contain more or less
fixed air, but always much less than the purely animal or vegetable
substances. This fixed air can be equally removed by combustion. In
animal and vegetable matters it is disengaged by simple fermentation,
which, like combustion, has always need of air for its operation.
Sulphurs and pyrites are not the only minerals Which must be looked
upon as combustible, there are many others which I shall not here
enumerate, because it is sufficient to remark, their degree of
combustion depends commonly on the quantity of sulphur which they
contain. All combustible minerals originally derive this property
either from the mixture of animal or vegetable parts which are
incorporated with them, or from the particles of light, heat, and air,
which, by the lapse of time, are fixed in their internal part. Nothing,
according to my opinion, is combustible but that which has been formed
by a gentle heat, that is, by these same elements combined in all the
substances which the sun brightens and vivifies, or in that which the
internal heat of the earth foments and unites.
The internal heat of the globe of the earth must be regarded as the
true elementary fire; it is always subsisting and constant; it enters,
like an element, into all the combinations of the other elements, and
is more than sufficient to produce the same effects on air as actual
fire on animal heat; consequently this internal heat of the earth
will destroy the elasticity of the air, and render it fixed, which
being divided into minute parts will enter into a great number of
substances, from hence they will contain articles of fixed air and
fire, which are the first principles of combustibility; but they will
be found in different quantities, according to their degree of affinity
with the substance, and this degree will greatly depend on the quantity
these substances contain of animal and vegetable parts, which appear to
be the base of all combustible matter. Most metallic minerals, and even
metals, contain great quantities of combustible parts; zinc, antimony,
iron, copper, &c. burn and produce a very brisk flame, as long as the
combustion of these inflammable parts remains, after which, if the fire
be continued, the calcination begins, during which there enters into
them new parts of air and heat, which fixes, and cannot be disengaged
but by presenting to them combustible matters, with which they have a
greater affinity than with those of the mineral, with which they are
only united by the effort of calcination. It appears to me, that the
conversion of metallic substances into dross, and their reproduction,
might be very clearly understood without applying to secondary
principles, or arbitrary hypotheses, for their explanation.
Having considered the action of fixed air in the most secret operations
of nature, let us take a view of it when it resides in bodies under
an elastic form; its effects are then as variable as the degrees of
its elasticity, and its action, though always the same, seems to give
different products in different substances. To bring this consideration
back to a general point of view, we will compare it with water and
earth, as we have already compared it with fire; the results of this
comparison between the four elements will afterwards be easily applied
to every substance, since they are all composed merely of these four
real principles.
The greatest cold that is known, cannot destroy the spring of the air,
and the least heat is sufficient for that purpose, especially when this
fluid is divided into very small particles. But it must be observed,
that between its state of fixity, and that of perfect elasticity, there
are all the links of the intermediate states, in one of which it always
resides in earth and water, and all the substances which are composed
of them; for example, water, which appears so simple a substance,
contains a certain quantity of air, which is neither fixed nor elastic,
as is plain from its congulation, ebullition, and resistance to all
compression, &c. Experimental philosophy demonstrates, that water is
incompressible, for instead of shrinking and entering into itself when
pressed, it passes through the most solid and thickest vessels; which
could not be the case if the air it contained were in a state of full
elasticity. The air contained therefore in water, is not simply mixed
therewith, but is united in a state where its spring is not sensibly
exercised; yet the spring is not entirely destroyed, for if we expose
water to congelation, the air issues from its internal part, and unites
on its surface in elastic bubbles. This alone suffices to prove, that
air is not contained in water under its common form, since being
specifically 850 times lighter, it would be forced to issue out by the
sole necessity of the preponderance of water; neither under an affixed
form, but only in a medium state, from whence it can easily retake its
spring, and separate more easily than from every other matter.
It may, with some justice, be objected that cold and heat never operate
in the same mode, and that if one of these causes gives to air its
elasticity, the other must destroy it, and I own that in general it
is so, but in this particular they produce the same effect. It is
well known that water, frozen or boiled, reabsorbs the air it had
lost as soon as it is liquefied or cooled. The degree of affinity
of air with water, depends, therefore, in a great measure, on its
temperature, which in its liquid state; is nearly the same as that of
the general heat, to the surface of the earth: the air with which it
has much affinity penetrates it as soon as it is divided into small
parts, yet the degree of elementary and general heat, weakens their
spring so as to render them ineffectual as long as the water preserves
this temperature; but if the cold penetrate, or this degree of heat
diminish, then its spring will be re-established by the cold, and the
elastic bubbles will rise to the surface of the water ready to freeze;
if, on the contrary, the temperature of the water is increased by an
external heat, the integrant parts become too much divided, they are
rendered volatile, and the air with which they are united, rises and
escapes with them. Water and air have much greater connections between
them than opposite properties, and as I am well persuaded, that all
matter is convertible, and that the elements may be transformed, I am
inclined to believe, that water can change into air when sufficiently
rarefied to raise up in vapours, for the spring of the vapour of the
water is even more powerful than the spring of the air.
Experience has taught me that the vapours of water can increase the
fire in the same manner as common air; and this air, which we may
regard as pure, is always mixed with a very great quantity of water;
but it must be remarked, as an observation of much importance, that
the proportions of the mixtures are not nearly the same in these two
elements. It may be said in general that there is much less air in
water than water in air. In considering this proportion we must refer
to the volume and mass. If we estimate the quantity of air contained in
water by the volume it will appear nil, since the volume is not in the
least increased. Thus it is not to the volume that we must relate this
proportion, it is alone to the mass, that is, to the real quantity of
matter in one and the other of these two elements that we must compare
that of their mixture, by which we shall perceive that the air is much
more _aqueous_ than the water is _aerial_, perhaps in proportion of the
mass, that is, eight hundred and fifty times. Be this estimation either
too strong or too weak we can derive this induction from it, that water
must change more easily into air than air can transform into water.
The parts of air, although susceptible of being extremely divided,
appear to be more gross than those of water, since the latter passes
through many filtres which air cannot penetrate; since the vapours of
water are only raised to a certain height in the air; and, in short,
since air seems to imbibe water like a sponge, to contain it in a
large quantity, and that the container is certainly greater than the
contained.
In the order of the conversion of the elements it appears to me, that
water is to air what air is to fire, and that all the transformations
of nature depend on them. Air, like the food of fire, assimilates with
it, and is transformed into this first element. Water, rarefied by
heat, is transformed into a kind of air capable of feeding the fire
like common air. Thus fire has a double fund of certain subsistence;
if it consume much air it can also produce much by the rarefaction of
water, and thus repair, in the mass of atmosphere, all the quantity
it destroyed, while ulteriorly it converts itself with air into fixed
matter in the terrestrial substances which it penetrates by its heat
or by its light. And so, likewise, as water is converted into air,
or into vapours, as volatile as air, by its rarefaction, it is also
converted into a solid substance by a kind of condensation. Every fluid
is rarefied by heat and condensed by cold. Water follows this common
law, and condenses as it grows cold. Let a glass tube be filled three
parts full and it will descend in proportion as the cold increases, but
some time before congelation it will ascend above the point of three
fourths of the height of the tube, and increase still more considerably
by being frozen. But if the tube be well stopped, and perfectly at
rest, the water will continue to descend, and will not freeze, although
the degree of cold be six, eight, or ten degrees below the freezing
point; congelation, therefore, presents, in an inverted manner, the
same phenomena as inflammation. A heat, however great, shut up in a
well-closed vessel, will not produce inflammation unless touched with
an inflamed matter; so, likewise, to whatsoever degree a fluid is
cooled, it will not freeze unless it touch something already frozen,
and this is what happens when the tube is shaken or uncorked; the
particles of water, which are frozen in the external air, or in the air
contained in the tube, strike the surface of the water, and communicate
their ice to it. In inflammation, the air, at first very much rarefied
by heat, loses its volume, and fixes itself suddenly. In congelation,
water, at first condensed by the cold, takes a larger volume, and fixes
itself likewise, for ice is a solid substance, lighter than water, and
would preserve its solidity if the cold continued the same; and I am
inclined to believe that we may attain the point of fixing mercury at
a less degree of cold, by sublimating it into vapours in a very cold
air; and also that water, which only owes its liquidity to heat, would
become a substance much more solid and fusible, as it would endure a
stronger and a longer time the rigour of the cold.
But without stopping upon this subject, that is, without admitting or
excluding the possibility of the conversion of the ice into infusible
matter, or fixed and solid earth, let us pass on to more extensive
views on the modes which Nature makes use of for the transformation
of water. The most powerful of all and the most evident is the animal
filter. The body of shell-animals, by feeding on the particles of
water, labours, at the same time, on the substance to the point of
unnaturalizing it. The shell is certainly a terrestrial substance,
a true stone, from which all the stones called calcareous, and many
other matters, derive their origin. This shell appears to make the
constitutive part of the animal it covers, since it is perpetuated
by generation, for it is on the small shell-animal just come into
existence as well as on those which have arrived at their full growth;
but this is no less a terrestrial substance, formed by the secretion
or exudation of the body, for it increases and thickens by rings
and layers in proportion as the animal grows; and stony matter often
exceeds fifty or sixty times the mass of the body which produces
it. Let us, for a moment, reflect on the number of the kind of
shell-animals, or rather of those animals with a stony transudation;
they, possibly, are more numerous in the sea than the insect kind
are upon earth. Let us afterwards represent their full growth, their
prodigious multiplication, and the shortness of their lives, which
we may suppose does not exceed ten years; let us then consider that
we must multiply by fifty or sixty the almost immense number of the
individuals of this class to form an idea of all the stony matter
produced in ten years; then that this block must be augmented with as
many similar blocks as there are as many times ten in all the ages from
the beginning of the world, and by this means we shall conceive, that
all our coral, rocks of calcareous stone, marble, chalk, &c. originally
proceeded alone from the cast-off coats of those little animals.
Salts, bitumen, oil, and the grease of the sea, enter little or none
into the composition of the shell; neither does the calcareous stone
contain any of those matters; this stone is, therefore, only water
transformed, joined to some little portion of vitrifiable earth, and to
a great quantity of fixed air, which may be disengaged by calcination.
This operation produces the same effect on the shells taken in the sea
as upon those drawn out of quarries; they both form lime, with only a
little difference in their quality. Lime, made with oyster or other
shells, is weaker than that made with marble or hard stone; but the
process of Nature is the same, as are the results of its operation.
Both shells and stones, lose nearly half their weight by the action
of fire in calcination; the water issues first, after which the fixed
air is disengaged, and then the fixed water, of which these stony
substances are composed, resumes its primitive nature, is elevated into
vapours, drove off and rarefied by the fire, so that there remains
only the most fixed parts of this air and water, which, perhaps, are
so strongly united in themselves, and to the small quantity of the
fixed earth of the stone, that the fire cannot separate them; the
mass, therefore, is reduced nearly a half, and would probably be still
more if submitted to a stronger fire. And what appears to me to prove
that this matter, driven out of the stone by the fire, is nothing else
than air and water, is the avidity with which calcined stone sucks up
the water given to it, and the force with which it draws water from
the atmosphere. Lime, by exposure either in air or water, in a great
measure regains the mass it had lost by calcination; the water, with
the air it contains, replaces that which the stone contained before.
Stone then retakes its first nature, for in mixing lime with the
remains of other stones, a mortar is made which hardens, and becomes a
solid substance, like those from which it is composed.
Thus, then, we see on the one hand all the calcareous matters, the
origin of which we must refer to animals; and on the other, all the
combustible matters proceeding from animal or vegetable substances;
they occupy together a great space on the earth; yet, however great
their number may be, they only form a small part of the terrestrial
globe, the principal foundation of which, and the greatest quantity
consists in one matter of the nature of glass; a matter we must look
upon as terrestrial element, to the exclusion of all other substances,
to which it serves as a base, like earth, when it forms vegetables by
the means, or remains of animals, and by the transformation of the
other elements; and it is also the ulterior term to which we can return
or reduce them all.
It appears that the animal filter converts water into stone; the
vegetable filter can also transform it, when all the circumstances are
found to be the same. The heat of vegetables and the organs of life
being less powerful than those of shell animals, the vegetables can
produce only a small quantity of stones, which are frequently found
in its fruits; but it can and does convert a great quantify of air,
and a still greater of water into its substance. It may be asserted,
without fear of contradiction, that the fixed earth it appropriates,
and which serves as a base to these two elements, does not make the
hundredth part of its mass; hence, the vegetable is almost entirely
composed of air and water, transformed into wood, or a solid substance,
which is afterwards reduced into earth by combustion and putrefaction.
The same may be said of animals; they not only fix and transform air
and water, but fire, and in a much greater quantity than vegetables.
It appears, therefore, to me, that the functions of organized bodies
are the most powerful means made use of by Nature for the conversion
of the elements. We may regard each animal, or vegetable, as a small
particular centre of heat or fire that appropriates to itself the air
and water which surround it, assimilates them to vegetate or nourish,
and live on the productions of the earth, which are themselves only
air and water previously fixed. It also appropriates to itself a small
quantity of earth, and receiving the impressions of light, the heat of
the sun and terrestrial globe, it converts into its substance all these
different elements; works, combines, unites, and opposes them, till
they have undergone the necessary form towards its support of life, and
the growth of organization, the mold of which once given, models every
matter it admits, and from inanimate renders it organized.
Water, which so readily coalesces and enters with air into organized
bodies, unites also with some solid matters, such as salts; and it is
often by their means that it enters into the composition of minerals.
Salt at first appears to be only an earth soluble in water, and of
a sharp flavour, but chemists have perfectly discovered, that it
principally consists in the union of what they term the _earthly_ and
the _aqueous principle_. The experiment of the nitrous acid, which
after combustion leaves only a small quantity of earth and water,
has caused them to think, that salt was composed only of these two
elements; yet I think it is easily to be demonstrated, that air and
fire also enter their composition; since nitre produces a great
quantity of air in combustion, and this fixed air supposes fixed fire
which disengages at the same time: besides all the explanations given
of the dissolution cannot be supported, and it would be against all
analogy, that salt should be composed only of these two elements, while
all other substances are composed of four. Hence we must not receive
literally what those great chemists Messrs. Stahl and Macquer have
said on this subject; the experiments of Mr. Hales demonstrate, that
vitriol and marine salt contain much fixed air; that nitre contains
still more, even to the eighth of its weight; and that salt of tartar
contains still more than these. It may, therefore, be asserted that air
enters as a principle into the composition of all salts; but this does
not support the idea that salt is the mediate substance between earth
and water; these two elements enter in different proportions into the
different salts or saline substances, whose variety and number are so
great, as not to be enumerated; but which, generally presented under
the denomination of acids and alkalis, shews us, that there is in
general more earth than water in the last, and more water than earth in
the first.
Nevertheless, water, although it may be intimately mixed with salts, is
neither fixed nor united there by a sufficient force to transform it
into a solid matter like calcareous stone; it resides in salt or acid
under its primitive form, and the best concentrated acid, or the most
deprived of water, which might be looked upon as liquid earth, only
owes its liquidity to the quantity of the air and fire it contains; and
it is no less certain, that they are indebted for their savour to the
same principles. An experiment which I have frequently tried, has fully
convinced me, that alkali is produced by fire. Lime made according
to the common mode, and put upon the tongue, even before slacked by
air or water, has a savour which indicates the presence of a certain
quantity of alkali. If the fire be continued, this lime by longer
calcination, becomes more poignant; and that drawn from furnaces, where
the calcination has subsisted for five or six months together, is
still more so. Now this salt was not contained in the stone before its
calcination; it augmented in proportion to the strength and continuance
of the fire; it is therefore evident, that it is the immediate product
of the fire and air, which incorporate in the substance during its
calcination, and which, by this means, are become fixed parts of it,
and from which they have driven most of the watery molecules it before
contained. This alone appeared to me sufficient to pronounce that fire
is the principal of the formation of the mineral alkali; and we may
conclude, by analogy, that other alkalis owe their formation to the
constant heat of the animal and vegetable from which they are drawn.
With respect to acids, although the demonstration of their formation
by fire and fixed air, is not so immediate as that of alkalis, yet it
does not appear less certain. We have proved, that nitre and phosphorus
draw their origin from vegetable and animal matters: that vitriol comes
from pyrites, sulphur and other combustibles. It is likewise certain
that acids, whether vitriolic, nitrous, or phosphoric, always contain a
certain quantity of alkali; we must, therefore, refer their formation
and savour to the same principle, and by reducing the varieties of
both to one of each, bring back all salts to one common origin: those
which contain most of the active principles of air and fire, will
necessarily have the most power and taste. I understand by power the
force with which salts appear animated to dissolve other substances.
Dissolution supposes fluidity, and as it never operates between two
dry or solid matters, it also supposes the principle of fluidity in
the dissolvent, that is, fire; the power of the dissolvent will be,
therefore, so much the greater, as on one part it contains more of
this active principle; and, on the other hand, its aqueous and terrene
parts will have more affinity with those of the same kind contained
in the substances to dissolve; and, as the degrees of affinity vary,
we must not be surprized at different salts varying in their action
on different substances; their active principle is the same, their
dissolving power the same; but they remain without exercise when the
substance presented repels that of the dissolvent, or has no degree of
affinity with it; but the contrary is the case when there is sufficient
force of affinity to conquer that of the coherence; that is, when the
active principles, contained in the dissolvent, under the form of air
and fire, are found more powerfully attracted by the substance to be
dissolved, than they are by the earth and water they contain. Newton
is the first who has assigned affinities as the causes of chemical
precipitation; Stahl adopted this idea and transmitted it to all the
other chemists; and it appears to be at present universally received as
a truth. But neither Newton nor Stahl saw that all these affinities,
so different in appearance, are only particular effects of the general
force of universal attraction: and, for want of this knowledge, their
theory cannot be either luminous or complete, because they were obliged
to suppose as many trivial laws of different affinities, as there were
different phenomena; instead of which there is in fact only one law
of affinity, a law which is precisely the same as that of universal
attraction.
Salts concur in many operations of Nature by the power they have of
dissolving other substances; for, although it is commonly said, that
water dissolves salt, it is easy to be perceived, that in reality,
when there is a dissolution, both are active, and may be alike called
_dissolvents_. Regarding salt as only a dissolvent, the body to be
dissolved may be either liquid or solid; and, provided the parts of the
salt be sufficiently divided to touch immediately those of the other
substances, they will act and produce all the effects of dissolution.
By this we see how much the action of salts, and the action of the
element of water which contains them, must have influence on the
composition of mineral matters. Nature may produce by this mode, all
that our arts produce by that of fire. Time only is required for salts
and water to produce on the most compact and hard substances, the most
complete division and attenuation of their parts, so as to render them
capable of uniting with all analogous substances, and to separate from
all others; but this time, which to Nature is never wanting, is, of all
things, that which is the most deficient to us: the greatest of all our
arts, therefore, is that of abridging time, that is, to effect that
in one day, which nature takes an age to perform. However vain this
pretension may appear, we must not entirely renounce it, for has not
man discovered the mode of creating fire, of applying it to his use,
and by the means of this element to suddenly dissolve those bodies by
fusion which would require a considerable period by any other means?
We must not, however, conclude that Nature really performs by the means
of water all that we do by fire. The decomposition of every substance
is only to be made by division, and the greater this division the more
the decomposition will be complete. Fire seems to divide as much as
possible those matters which it fuses; nevertheless it may be doubted
whether those which water and acids keep in dissolution are not still
more divided, and the vapours raised by heat contain matters still
further attenuated, in the bowels of the earth, then, by the means
of the heat it includes, and the water which insinuates, there is
made an infinity of sublimations; distillations, chrystallizations,
aggregations, and disjunctions, of every kind. By time all substances
may be compounded and decompounded by these means; water may divide
and attenuate the parts more than fire when it melts them, and those
attenuated parts will join in the same manner as those of fused metal
unite by cooling. Crystallization, of which the salts have given us
an idea, is never performed but when a substance, being disengaged
from every other, is much divided and sustained by a fluid, which
having little or no affinity with it, permits it to unite and form by
virtue of its force of attraction, masses of a figure nearly similar
to its primitive parts. This operation, which supposes all the above
circumstances, may be done by the intermediate aid of fire as well as
by that of water, and is often accomplished by the concurrence of both,
because all this exacts but one division of matter sufficiently great
for its primitive parts to be able to form, by uniting figured bodies
like themselves. Now fire can bring many substances to this state much
better than any other dissolvent, as observation demonstrates to us in
asbestos, and other productions of fire, whose figures are regular, and
which must be looked upon as true crystallizations. Yet this degree of
division, necessary to crystallization, is not the greatest possible,
since in this state the small parts of matter are still sufficiently
large to constitute a mass, which like other masses, is only obedient
to the sole attractive force, and the volumes of which, only touching
in points, cannot acquire the resultive force that a much greater
division might perform by a more immediate contact, and this is what
we see happen in effervescences, where at once, heat and light are
produced by the mixture of two cold liquors.
Light, heat, fire, air, water, and salts, are steps by which we descend
from the top of Nature's ladder to its base, which is fixed earth. And
these are at the same time the only principles that we must admit and
combine for the explanation of all phenomena. These principles are
real, independently of all hypotheses and all method, as are also their
conversion and transformation, which are demonstrated by experience.
It is the same with the element of earth, it can convert itself by
volatilizing and taking the form of the other elements, as those take
that of earth in fixing; it, therefore, appears quite useless to seek
for a substance of pure earth in terrestrial matters. The transparent
lustre of the diamond dazzled the sight of our chemists, when they
considered that stone as a pure elementary fire; they might have said
with as much foundation, that it is pure water, all the parts of which
are fixed to compose a solid diaphanous substance. When we would define
Nature, the large masses should alone be considered, and those elements
have been well taken notice of by even the most ancient philosophers.
The sun, atmosphere, earth, sea, &c. are all great masses on which
they established all their conclusions; and if there ever had existed
a planet of phlogiston, an atmosphere of alkali, an ocean of acid,
or a mountain of diamonds, such might have been looked upon as the
general and real principles of all bodies, but they are only particular
substances, produced, like all the rest, by the combinations of true
elements; and ideas to the contrary would never have been started but
upon the supposition that the earth was neither more simple nor less
convertible than either of the other elements.
In the great mass of solid matter, which the earth represents, the
superficial is the least pure. All the matter deposited by the sea, in
form of sediment, all stones produced by shell-animals, all substances
composed by the combinations of the waste of the animal or vegetable
kingdom, and all those which have been changed by the fires of
volcanos, or sublimated by the internal heat of the globe, are mixed
and transformed substances; and although they compose great masses
they do not clearly represent to us the element of earth. They are
vitrifiable matters, whose mass must be considered as 100,000 times
more considerable than all those other substances, which should be
regarded as the true basis of this element. It is from this common
foundation that all other substances have derived the origin of their
solidity, for all fixed matter, however much decomposed, subsides
finally into glass by the sole action of fire: it resumes its first
nature, when disengaged from the fluid, or volatile matters, which were
united with it; and this glass, or virtreous matter, which composes
the mass of our globe, represents so much the better the element of
earth, as it has neither colour, smell, taste, liquidity, nor fluidity,
qualities which all proceed from the other elements, or belong to them.
If glass be not precisely the element of earth, it is at least the most
ancient substance of it; metals are more recent, and less dignified;
and most other minerals form within our sight. Nature produces glass
only in the particular focus of its volcanos, whereas every day she
forms other substances by the combination of glass with the other
elements. If we would form to ourselves a just idea of her formation
of the globe, we must first consider her processes, which demonstrate
that it has been melted or liquefied by fire; that from this immense
heat it successively passed to its present degree; that in the first
moments, where its surface began to take consistence, inequalities
must be formed, such as we see on the surface of melted matters grown
cold: that the highest mountains, all composed of vitrifiable matters,
existed and take their date from that moment, which is also that of
the separation of the great masses of air, water, and earth; that
afterwards, during the long space of time which the diminution of the
heat of the globe to the point of present temperature supposes, there
were made in these mountains, which were the parts most exposed to
the action of external causes, an infinity of fusions, sublimations,
aggregations, and transformations, by the fire of the sun, and all the
other causes which this great heat rendered more active than they at
present are, and that consequently we must refer back to this date the
formation of metals and minerals which we find in great masses, and in
thick and continued veins. The violent fire of inflamed earth, after
having raised up and reduced into vapours all that was volatile, after
having driven off from its internal parts the matters which compose
the atmosphere and the sea, and at the same time sublimated all the
least fixed parts of the earth, raised them up and deposited them in
every void space, in all the cavities which formed on the surface in
proportion as it cooled; this, then, is the origin and the gradation
of the situation and formation of vitrifiable matters which fire has
divided, formed and sublimated.
After this first establishment (and which still subsists) of
vitrifiable matters and minerals into a great mass, which can be
attributed to the action of fire alone, water which till then formed
with air only a vast volume of vapours, began to take its present
state; it collected and covered the greatest part of the surface of
the earth, on which, finding itself agitated by a continual flux
and reflux, by the action of winds and heat, it began to act on the
works of fire: it changed, by degrees, the superficies of vitrifiable
matters; it transported the wrecks and deposited them in the form of
sediments; it nourished shell-animals, it collected their shells,
produced calcareous stones, formed hills and mountains, which becoming
afterwards dry, received in their cavities all the mineral matters they
could dissolve or contain.
To establish a general theory on the formation of Minerals, we must
begin then by distinguishing with the greatest attention, first, those
which have been produced by the primitive fire of the earth while it
was burning with heat; secondly, those which have been formed from the
waste of the first by the means of water; and thirdly, those which
in volcanos, or other subsequent conflagrations, have a second time
undergone the proof of a violent heat. These three objects are very
distinct, and comprehend all the mineral kingdom; by not losing sight
of them, and by connecting each substance, we can scarcely be deceived
in its origin, or even in the degrees of its formation. All minerals
which are found in masses, or large veins in our high mountains,
must be referred to the sublimation of the primitive fire; all those
which are found in small ramifactions, in threads or in vegetations,
have been formed only from the waste of the first hurried away by the
stillation of waters. We are evidently convinced of this, by comparing
the matter of the iron mines of Sweden with that of our own. These
are the immediate work of water, and we see them formed before our
eyes; they are not attracted by the load stone; they do not contain
any sulphur, and are found only dispersed in the earth; the rest are
all more or less sulphureous, all attracted by the load stone, which
alone supposes that they have undergone the action of fire; they are
disposed in great, hard, and solid masses: and their substance is mixed
with a quantity of asbestos, another index of the action of fire. It is
the same with other metals: their ancient foundation comes from fire,
and all their great masses have been united by its action; but all
their crystallizations, vegetations, granulations, &c. are due to the
secondary causes, in which water is the primary agent.