attraction between the parts of matter, and of the centrifugal force,
which results from its diurnal rotation, the earth has necessarily taken
the form of a spheroid, the diameters of which differ about a 230th
part, and that it could only proceed from the changes on the surface,
caused by the motion of the air and water, that this difference could
become greater, as is pretended to be the case from the measures taken
under the equator, and within the polar circle. This figure of the
earth, which so well agrees with hydrostatical laws, and with our
theory, supposes the globe to have been in a state of liquefaction when
it assumed its form, and we have proved that the motions of projection
and rotation were imprinted at the same time by a like impulsion. We
shall the more easily believe that the earth has been in a state of
liquefaction produced by fire, when we consider the nature of the
matters which the globe incloses, the greatest part of which are
vitrified or vitrifiable; especially when we reflect on the
impossibility there is that the earth should ever have been in a state
of fluidity, produced by the waters; since there is infinitely more
earth than water, and that water has not the power of dissolving stone,
sand, and other matters of which the earth is composed.
It is plain then that the earth took its figure at the time when it was
liquefied by fire: by pursuing our hypothesis it appears, that when the
sun quitted it, the earth had no other form than that of a torrent of
melted and inflamed vapour matter; that this torrent collected itself by
the mutual attraction of its parts, and became a globe, to which the
rotative motion gave the figure of a spheroid; and when the earth was
cooled, the vapours, which were first extended like the tails of comets,
by degrees condensed and fell upon the surface, depositing, at the same
time, a slimy substance mixed with sulphurous and saline matters, a part
of which, by the motion of the waters, was swept into the perpendicular
cracks, where it produced metals, while the rest remained on the
surface, and produced that reddish earth which forms the first strata;
and which, according to different places, is more or less blended with
animal and vegetable particles, so reduced that the organization is no
longer perceptible.
Therefore, in the first state of the earth, the globe was internally
composed of vitrified matter, as I believe it is at present, above which
were placed those bodies the fire had most divided, as sand, which are
only fragments of glass; and above these, pumice stones and the scoria
of the vitrified matter, which formed the various clays; the whole was
covered with water 5 or 600 feet deep, produced by the condensation of
the vapours, when the globe began to cool. This water every where
deposited a muddy bed, mixed with waters which sublime and exhale by the
fire; and the air was formed of the most subtile vapours, which, by
their lightness, disengaged themselves from the waters, and surmounted
them.
Such was the state of the globe when the action of the tides, the winds,
and the heat of the sun, began to change the surface of the earth. The
diurnal motion, and the flux and reflux, at first raised the waters
under the southern climate, which carried with them mud, clay, and sand,
and by raising the parts of the equator, they by degrees perhaps lowered
those of the poles about two leagues, as we before mentioned; for the
waters soon reduced into powder the pumice stones and other spongeous
parts of the vitrified matter that were at the surface, they hollowed
some places, and raised others, which in course of time became
continents, and produced all the inequalities, and which are more
considerable towards the equator than the poles; for the highest
mountains are between the tropics and the middle of the temperate zones,
and the lowest are from the polar circle to the poles; between the
tropics are the Cordeliers, and almost all the mountains of Mexico and
Brazil, the great and little Atlas, the Moon, &c. Beside the land which
is between the tropics, from the superior number of islands found in
those parts, is the most unequal of all the globe, as evidently is the
sea.
However independent my theory may be of that hypothesis of what passed
at the time of the first state of the globe, I refer to it in this
article, in order to shew the connection and possibility of the system
which I endeavoured to maintain in the first article. It must only be
remarked, that my theory does not stray far from it, as I take the earth
in a state nearly similar to what it appears at present, and as I do not
make use of any of the suppositions which are used on reasoning on the
past state of the terrestrial globe. But as I here present a new idea on
the subject of the sediment deposited by the water, which, in my
opinion, has perforated the upper bed of earth, it appears to me also
necessary to give the reason on which I found this opinion.
The vapours which rise in the air produce rain, dew, aerial fires,
thunder, and other meteors. These vapours are therefore blended with
aqueous, aerial, sulphurous and terrestrial particles, &c. and it is the
solid and earthy particles which form the mud or slime we are now
speaking of. When rain water is suffered to rest, a sediment is formed
at bottom; and having collected a quantity, if it is suffered to stand
and corrupt, it produces a kind of mud which falls to the bottom of the
vessel. Dew produces much more of this mud than rain water, which is
greasy, unctuous, and of a reddish colour.
The first strata of the earth is composed of this mud, mixed with
perished vegetable or animal parts, or rather stony and sandy particles.
We may remark that almost all land proper for cultivation is reddish,
and more or less mixed with these different matters; the particles of
sand or stone found there are of two kinds, the one coarse and heavy,
the other fine and sometimes impalpable. The largest comes from the
lower strata loosened in cultivating the earth, or rather the upper
mould, by penetrating into the lower, which is of sand and other divided
matters, and forms those earths we call fat and fertile. The finer sort
proceeds from the air, and falls with dew and rain, and mixes intimately
with the soil. This is properly the residue of the powder, which the
wind continually raises from the surface of the earth, and which falls
again after having imbibed the humidity of the air. When the earth
predominates, and the stony and sandy parts are but few, the earth is
then reddish and fertile: if it is mixed with a considerable quantity of
perished animal or vegetable substances, it is blackish, and often more
fertile than the first; but if the mould is only in a small quantity, as
well as the animal or vegetable parts, the earth is white and sterile,
and when the sandy, stony, or cretaceous parts which compose these
sterile lands, are mixed with a sufficient quantity of perished animal
or vegetable substances, they form the black and lighter earths, but
have little fertility; so that according to the different combinations
of these three different matters, the land is more or less fecund and
differently coloured.
To fix some ideas relative to these stratas; let us take, for example,
the earth of Marly-la-ville, where the pits are very deep: it is a high
country, but flat and fertile, and its strata lie arranged horizontally.
I had samples brought me of all these strata which M. Dalibard, an able
botanist, versed in different sciences, had dug under his inspection;
and after having proved the matters of which they consisted in
aquafortis, I formed the following table of them.
The state of the different beds of earth, found at Marly-la-ville,
to the depth of 100 feet.
Feet. In.
1. A free reddish earth, mixed with
much mud, a very small quantity of
vitrifiable sand, and somewhat more of
calcinable sand 13 0
2. A free earth mixed with gravel,
and a little more vitrifiable sand 2 6
3. Mud mixed with vitrifiable sand
in a great quantity, and which made
but very little effervescence with
aquafortis 3 0
4. Hard marl, which made a very
great effervescence with aquafortis 2 0
5. Pretty hard marl stone 4 0
6. Marl in powder, mixed with vitrifiable
sand 5 0
7. Very fine vitrified sand 1 6
8. Marl very like earth mixed with
a very little vitrifiable sand 3 6
9. Hard marl, in which was real flint 3 6
10. Gravel, or powdered marl 1 0
11. Eglantine, a stone of the grain
and hardness of marble, and sonorous 1 6
12. Marly gravel 1 6
13. Marl in hard stone, whose grain
was very fine 1 6
14. Marl in stone, whose grain was
not so fine 1 6
15. More grained and thicker marl 2 6
16. Very fine vitrifiable sand, mixed
with fossil sea-shells, which had no
adherence with the sand, and whose
colours were perfect 1 6
17. Very small gravel, or fine marl
powder 2 0
18. Marl in hard stone 3 6
19. Very coarse powdered marl 1 6
20. Hard and calcinable stone, like
marble 1 0
21. Grey vitrifiable sand mixed with
fossil shells, particularly oysters and
muscles which have no adherence
with the sand, and which were not
petrified 3 0
22. White vitrifiable sand mixed with
similar shells 2 0
23. Sand streaked red and white,
vitrifiable and mixed with the like
shells 1 0
24. Larger sand, but still vitrifiable
and mixed with the like shells 1 0
25. Fine and vitrifiable grey sand
mixed with the like shells 8 6
26. Very fine fat sand, with only a
few shells 3 0
27. Brown free stone 3 0
28. Vitrifiable sand, streaked red and
white 4 0
29. White vitrifiable sand 3 6
30. Reddish vitrifiable sand 15 0
--------
Total depth 101 0
--------
I have before said that I tried all these matters in aquafortis, because
where the inspection and comparison of matters with others that we are
acquainted with is not sufficient to permit us to denominate and range
them in the class which they belong, there is no means more ready, nor
perhaps more sure, than to try by aquafortis the terrestrial or
lapidific matter: those which acid spirits dissolve immediately with
heat and ebullition, are generally calcinable, and those on which they
make no impression are vitrifiable.
By this enumeration we perceive, that the soil of Marly-la-ville was
formerly the bottom of the sea, which has been raised above 75 feet,
since we find shells at that depth below the surface. Those shells have
been transported by the motion of the water, at the same time as the
sand in which they are met with, and the whole of the upper strata, even
to the first, have been transported after the same manner by the motion
of the water, and deposited in form of a sediment; which we cannot
doubt, as well by reason of their horizontal position, as of the
different beds of sand mixed with shells and marl, the last of which are
only the fragments of the shells. The last stratum itself has been
formed almost entirely by the mould we have spoken of, mixed with a
small part of the marl which was at the surface.
I have chosen this example, as the most disadvantageous to my theory,
because it at first appears very difficult to conceive that the dust of
the air, rain and dew, could produce strata of free earth thirteen feet
thick; but it ought to be observed, that it is very rare to find,
especially in high lands, so considerable a thickness of cultivateable
earth; it is generally about three or four feet, and often not more than
one. In plains surrounded with hills, this thickness of good earth is
the greatest, because the rain loosens the earth of the hills, and
carries it into the vallies; but without supposing any thing of that
kind, I find that the last strata formed by the waters are thick beds of
marl. It is natural to imagine that the upper stratum had, at the
beginning, a still greater thickness, besides the thirteen feet of marl,
when the sea quitted the land and left it naked. This marl, exposed to
the air, melted with the rain; the action of the air and heat of the sun
produced flaws, and reduced it into powder on the surface; the sea would
not quit this land precipitately, but sometimes cover it, either by the
alternative motion of the tides, or by the extraordinary elevation of
the waters in foul weather, when it mixed with this bed of marl, mud,
clay, and other matters. When the land was raised above the waters,
plants would begin to grow, and it was then that the dust in the rain or
dew by degrees added to its substance and gave it a reddish colour; this
thickness and fertility was soon augmented by culture; by digging and
dividing its surface, and thus giving to the dust, in the dew or rain,
the facility of more deeply penetrating it, which at last produced that
bed of free earth thirteen feet thick.
I shall not here examine whether the reddish colour of vegetable earth
proceeds from the iron which is contained in the earths that are
deposited by the rains and dews, but being of importance, shall take
notice of it when we come to treat of minerals; it is sufficient to have
explained our conception of the formation of the superficial strata of
the earth, and by other examples we shall prove, that the formation of
the interior strata, can only be the work of the waters.
The surface of the globe, says Woodward, this external stratum on which
men and animals walk, which serves as a magazine for the formation of
vegetables and animals, is, for the greatest part, composed of vegetable
or animal matter, and is in continual motion and variation. All animals
and vegetables which have existed from the creation of the world, have
successively extracted from this stratum the matter which composes it,
and have, after their deaths, restored to it this borrowed matter: it
remains there always ready to be retaken, and to serve for the formation
of other bodies of the same species successively, for the matter which
composes one body is proper and natural to form another body of the same
kind. In uninhabited countries, where the woods are never cut, where
animals do not brouze on the plants, this stratum of vegetable earth
increases considerably. In all woods, even in those which are sometimes
cut, there is a bed of mould, of six or eight inches thick, formed
entirely by the leaves, small branches, and barks which have perished. I
have often observed on the ancient Roman way, which crosses Burgundy in
a long extent of soil, that there is formed a bed of black earth more
than a foot thick upon the stones, which nourishes very high trees; and
this stratum could be composed only of a black mould formed by the
leaves, bark, and perished wood. As vegetables inhale for their
nutriment much more from the air and water than the earth, it happens
that when they perish, they return to the earth more than they have
taken from it. Besides, forests collect the rain water, and by stopping
the vapours increase their moisture; so in a wood which is preserved a
long time, the stratum of earth which serves for vegetation increases
considerably. But animals restoring less to the earth than they take
from it, and men making enormous consumption of wood and plants for
fire, and other uses, it follows that the vegetable soil of inhabited
countries must diminish, and become, in time, like the soil of Arabia
Petrea, and other eastern provinces, which, in fact, are the most
ancient inhabited countries, where only sand and salt are now to be met
with; for the fixed salts of plants and animals remain, whereas all the
other parts volatilise, and are transported by the air.
Let us now examine the position and formation of the interior strata:
the earth, says Woodward, appears in places that have been dug, composed
of strata placed one on the other, as so many sediments which
necessarily fell to the bottom of the water; the deepest strata are
generally the thickest, and those above the thinnest, and so gradually
lessening to the surface. We find sea shells, teeth, and bones of fish
in these different beds, and not only in those that are soft, as chalk
and clay, but even in those of hard stone, marble, &c. These marine
productions are incorporated with the stone, and when separated from
them, leave the impressions of the shells with the greatest exactness.
"I have been most clearly and positively assured," says this author,
"that in France, Flanders, Holland, Spain, Italy, Germany, Denmark,
Norway, and Sweden, stone, and other terrestrial substances are disposed
in strata, precisely the same as they are in England; that these strata
are divided by parallel fissures; that there are inclosed within stones
and other terrestrial and compact substances, a great quantity of shells
and other productions of the sea, disposed in the same manner as in this
island. I am also informed that these strata are found the same in
Barbary, Egypt, Guinea, and in other parts of Africa; in Arabia, Syria,
Persia, Malabar, China, and the rest of the provinces of Asia; in
Jamaica, Barbadoes, Virginia, New-England, Brazil, and other parts of
America[198:A]."
This author does not say how he learnt, or by whom he was told, that the
strata of Peru contained shells; yet as in general his observations are
exact, I do not doubt but he was well informed; and am persuaded that
shells may be found in the earth of Peru, as well as elsewhere. This
remark is made from a doubt having been formed some time since on the
subject, and which I shall hereafter consider.
In a trench made at Amsterdam, to the depth of 230 feet, the strata were
found as follows: 7 feet of vegetable earth, 9 of turf, 9 of soft clay,
8 of sand, 4 of earth, 10 of clay, 4 of earth, 10 of sand, then 2 feet
of clay, 4 of white sand, 5 of dry earth, 1 of soft earth, 14 of sand, 8
of argil, mixed with earth; 4 of sand, mixed with shells; then clay 102
feet thick, and at last 31 feet of sand, at which depth they ceased
digging[199:A].
It is very singular to dig so deep without meeting with water: and this
circumstance is remarkable in many particulars. 1. It shews, that the
water of the sea does not communicate with the interior part of the
earth, by means of filtration. 2. That shells are found at the depth of
100 feet below the surface, and that consequently the soil of Holland
has been raised 100 feet by the sediment of the sea. 3. We may draw an
induction, that this strata of thick clay of 102 feet, and the bed of
sand below it, in which they dug to 31 feet, and whose entire thickness
is unknown, are perhaps not very far distant from the first strata of
the original earth, such as it was before the motion of the water had
changed its surface. We have said in the first article, that if we
desired to find the ancient earth, we should dig in the northern
countries, rather than towards the south; in plains rather than in
mountainous regions. The circumstances in this instance, appear to be
nearly so, only it is to be wished they had continued the digging to a
greater depth, and that the author had informed us, whether there were
not shells and other marine productions, in the last bed of clay, and in
that of sand below it. The experiment confirms what we have already
said; and the more we dig, the greater thickness we shall find the
strata.
The earth is composed of parallel and horizontal beds, not only in
plains, but hills and mountains are in general composed after the same
manner: it may be said, that the strata in hills and mountains are more
apparent there than in the plains, because the plains are generally
covered with a very considerable quantity of sand and earth, which the
water has brought from the higher grounds, and therefore, to find the
ancient strata, must dig deeper in the plains than in the mountains.
I have often observed, that when a mountain is level at its summit, the
strata which compose it are also level; but if the summit is not placed
horizontally, the strata inclines also in the same direction. I have
heard that, in general, the beds of quarries inclined a little to the
east; but having myself observed all the chains of rocks which offered,
I discovered this opinion to be erroneous, and that the strata inclines
to the same side as the hill, whether it be east, west, north, or south.
When we dig stone and marble from the quarry, we take great care to
separate them according to their natural position, and we cannot even
get them of a large size, if we cut them in any other direction. Where
they are made use of for good masonry, the workmen are particular in
placing them as they stood in the quarry, for if they were placed in any
other direction, they would split, and would not resist the weight with
which they are loaded. This perfectly confirms that stones, are found
in parallel and horizontal strata, which have been successively heaped
one on the other, and that these strata composed masses where resistance
is greater in that direction than in any other.
Every strata, whether horizontal or inclined, has an equal thickness
throughout its whole extent. In the quarries about Paris the bed of good
stone is not thick, scarcely more than 18 or 20 feet: in those of
Burgundy the stone is much thicker. It is the same with marble; the
black and white marble have a thicker bed than the coloured; and I know
beds of very hard stone, which the farmers in Burgundy make use of to
cover their houses, that are not above an inch thick. The different
strata vary much in thickness, but each bed preserves the same thickness
throughout its extent. The thickness of strata is so greatly varied,
that it is found from less than a line to 1, 10, 20, 30, or 100 feet
thick. The ancient and modern quarries, which are horizontally dug, the
perpendicular and other divisions of mines, prove that there are
extensive strata in all directions. "It is thoroughly proved," says the
historian of the academy, "that all stones have formerly been a soft
paste, and as there are quarries almost in every part, the surface of
the earth has therefore consisted, in all these places, of mud and
slime, at least to certain depths. The shells found in most quarries
prove that this mud was an earth diluted by the water of the sea, and
consequently that the sea covered all these places; and it could not
cover them without also covering all that was level with or lower than
it: and it is plain that it could not cover every place where there were
quarries, without covering the whole face of the terrestrial globe. We
do not here consider the mountains which the sea must also at one time
have covered, since quarries and shells are often found in them.
"The sea," continues he, "therefore, covered the whole earth, and from
thence it proceeds that all the beds of stone in the plains are
horizontal and parallel; fish must have also been the most ancient
inhabitants of the globe, as there was no sustenance for either birds or
terrestrial animals." But how did the sea retire into these vast basins
which it at present occupies? What presents itself the most natural to
the mind is, that the earth, at least at a certain depth, was not
entirely solid, but intermixed with some great vacuums, whose vaults
were supported for a time, but at length, sunk in suddenly: then the
waters must have fallen into these vacancies, filled them, and left
naked a part of the earth's surface, which became an agreeable abode to
terrestrial animals and birds. The shells found in quarries perfectly
agree with this idea, for only the bony parts of fish could be preserved
till now. In general, shells are heaped up in great abundance in certain
parts of the sea, where they are immovable, and form a kind of rock, and
could not follow the water, which suddenly forsook them: this is the
reason that we find more shells than bones of the fish, and this even
proves a sudden fall of the sea into its present basins. At the same
time as our supposed vaults gave way, it is very possible that other
parts of the globe were raised by the same cause, and that mountains
were placed on this surface with quarries already formed, but the beds
of these quarries could not preserve the horizontal direction they
before had, unless the mountains were raised precisely perpendicular to
the surface of the earth, which could happen but very seldom: so also,
as we have already observed, in 1705, the beds of stone in mountains are
always inclined to the horizon, though parallel with each other; for
they have not changed their position with respect to each other, but
only with respect to the surface of the earth[205:A].