travellers. Middleton refers to the ibis, a bronze figure of a
bird, of which the beak is arched, but short, the neck very long,
and the head furnished with a small crest, a figure which never had
any resemblance to the bird of the Egyptians[363]. This figure is,
besides, not at all in the Egyptian style, and Middleton himself
agrees that it must have been made at Rome. Saumaise upon Solinus
says nothing that relates to the present question.
As to the black ibis, which Aristotle places only near Pelusium[364];
it was long thought that Belon alone had seen it[365]. The bird which
he describes under this name is a species of curlew, to which he
attributes a head similar to that of the cormorant, that is to say,
apparently bald, a red beak, and feet of the same colour; but as he
does not speak of the ibis in his journey[366], I suppose that it was
only in France that he made this reference, and by comparison with
mummies of the Ibis. What is certain is, that this curlew, with the
beak and feet red, was not known in Egypt[367], but that our green
curlew of Europe (_Scolopax Falcinellus_, Linn. Pl. Enl. 819.) is
seen very commonly there, that it is even more abundant than the
white numenius[368]; and, as it resembles it in form and size, and,
further, as its plumage may appear black, it can by no means be
doubted that it was the true black ibis of the ancients. M. Savigny
also made a drawing of it in Egypt, but from a young individual
only[369]. Buffon’s figure is from an adult bird; but its colours are
too pale.
The error which prevails at present respecting the white ibis began
with Perrault, who was also the first naturalist who made known the
Tantalus ibis of the present day. This error, adopted by Brisson
and Buffon, passed into the twelfth edition of Linnæus, where it is
blended with that of Hasselquist, which had been inserted in the
tenth, forming with it a compound altogether monstrous.
It was founded on the idea, that the ibis was essentially a bird that
destroyed serpents, and upon this very natural conclusion, that, in
order to enable it to devour these reptiles, it was necessary for it
to have a sharp beak, more or less resembling that of the heron. This
idea is even the only good objection that can be made against the
identity of our bird to the ibis. How, it is urged, could a bird with
a weak bill, a curlew, devour those dangerous reptiles?
It may be replied, that positive proofs, such descriptions, figures,
and mummies, ought always to preponderate over accounts of habits
too often imagined without any other motive than to justify the
different worships rendered to animals. It might be added, the
serpents from which the ibis delivered Egypt, are represented to
us as very venomous, but not as very large. I have even obtained a
direct proof that the birds preserved as mummies, which have had a
beak precisely similar to that of our bird, were true serpent eaters;
for I found in one of their mummies the still undigested remains
of the skin and scales of serpents, which I have deposited in our
anatomical galleries.
But, at the present day, M. Savigny, who has observed, in a living
state, and more than once dissected our white numenius, the bird
which every thing concurs to prove to have been the ibis, asserts
that it only eats worms, fresh water shells, and other small animals
of that sort. Supposing this fact to have no exception, all that can
be concluded from it is, that the Egyptians, as has happened more
than once to them and others, had invented a false reason for an
absurd worship. It is true that Herodotus says, he saw, in a place
on the borders of the desert[370], near Buto, a narrow gorge, in
which a multitude of bones were heaped up, which he was informed
were remains of winged serpents, that were seeking to penetrate into
Egypt in spring, and that the ibises had arrested their passage. But
he does not say that he had witnessed their combats, or that he had
seen those winged serpents in their entire state. The whole of his
testimony, therefore, reduces itself to this, that he had observed a
heap of bones, which may very well have been those of the multitude
of reptiles and other animals which the inundation destroyed every
year, and whose bodies it would naturally carry to the places where
it was stopped, to the borders of the desert, and which must by
preference have accumulated in a narrow gorge.
However, it is equally from this idea of the combats of the ibis with
serpents, that Cicero gives that bird a horny and strong beak[371].
Having never been in Egypt, he imagined that this must have been the
case by mere analogy.
I am aware that Strabo says somewhere, that the ibis resembles the
stork in form and size[372], and that this author ought to have
known it well, since he asserts that in his time the streets and
cross-ways of Alexandria were so filled with them, that they proved a
great inconvenience; but he must have spoken of it from memory. His
testimony cannot be received when he contradicts all the rest, and
especially when the bird itself is there to refute him.
In like manner, I shall not trouble myself about the passage where
Ælian[373] relates, according to the Egyptian embalmers, that the
intestines of the ibis are eighty-six cubits long. The Egyptian
priests of all classes have been guilty of so many extravagancies
with regard to Natural History, that no great importance can be
attributed to what one of their lowest classes might aver.
An objection might still be drawn against my opinion from the long
attenuated and black feathers which cover the rump of our bird,
and of which some traces also are seen in Bruce’s figure of the
Abou-Hannes. The ancients, it might be said, do not speak of them in
their descriptions, and their figures do not exhibit them. But I have
more on my side, in respect to this matter, than a written testimony
or a figured representation. I have found precisely the same feathers
in one of the Saccara mummies; I kept them carefully as being at
once a singular monument of antiquity and a peremptory proof of the
identity of species. These feathers having an uncommon form, and not
occurring, I believe, in any other curlew, leave, in fact, no doubt
respecting the accuracy of my opinion.
I conclude this memoir with a view of its results:
1. The Tantalus Ibis of Linnæus ought to constitute a separate genus,
along with the _Tantalus Loculator_. Their character would be:
_Rostrum læve, validum, arcuatum, apice utrinque emarginatum_.
2. The other Tantali of the last editions should form a genus with
the common curlews, to which the name of _Numenius_ might be given.
The character of the genus would be: _Rostrum teres, gracile,
arcuatum, apice mutico_. For the special character of the subgenus
of the Ibises, there should be added: _Sulco laterali per totam
longitudinem exarato_.
3. The white ibis of the ancients is not the ibis of Perrault and
Buffon, which is a _Tantalus_; nor the ibis of Hasselquist, which is
an _Ardea_; nor the ibis of Maillet, which is a _Vulture_; but it is
a bird of the genus Numenius, and of the sub-genus Ibis, which has
hitherto been described and figured only by Bruce, under the name of
_Abou-Hannes_. I give it the name of NUMENIUS IBIS, _albus, capite
et collo adulti nudis, remigum apicibus, rostro et pedibus nigris,
remigibus secondariis elongatis nigro-violaceis_.
4. The black ibis of the ancients is probably the bird which we
know in Europe under the name of Green Curlew, or the _Scolopax
Falcinellus_ of Linnæus. It also belongs to the genus Numenius, and
to the sub-genus Ibis.
5. The _Tantalus Ibis_ of Linnæus, in the present state of synonymy,
comprehends four species of three different genera, namely,
1. A Tantalus, the ibis of Perrault and Buffon;
2. An Ardea, the ibis of Hasselquist;
3. and 4. Two Numenii, the ibis of Belonius, and the ox-bird of Shaw.
From this example, and so many others, one may judge of the state in
which the _Systema Naturæ_ still exists, which it would be of so much
advantage to purge by degrees of the errors with which it abounds,
and which would seem to be every day increasing, by the addition of
species, characters, and synonyms, made without selection and without
critical examination.
The general conclusion of the whole investigation is, that the Ibis
still exists in Egypt, as it did in the days of the Pharaohs, and,
that it was owing to the inaccuracy of naturalists that the species
was for some time thought to be extinct, or to have been altered in
its forms.
GEOLOGICAL ILLUSTRATIONS,
BY
PROFESSOR JAMESON.
_In Civil History records are consulted, medals examined, and antique
inscriptions deciphered, in order to determine the epochs of human
revolutions, and verify moral events; so in Natural History we must
search the archives of the world; draw from the bowels of the earth
the monuments of former times; collect the fragments, and gather into
one body of proofs all the indices of physical changes, which may
enable us to retrace the different ages of nature. It is thus only
that we can fix some points in the immensity of space, and mark the
progressive stages in the eternal march of time._
ILLUSTRATIONS.
NOTE A and B, p. 9.
_On the Subsidence of Strata._
M. Cuvier adopts the opinion of De Luc, that all the older strata
of which the crust of the earth is composed, were originally in
an horizontal situation, and have been raised into their present
highly-inclined position, by subsidences that have taken place over
the whole surface of the earth.
It cannot be doubted, that subsidences, to a considerable extent,
have taken place; yet we are not of opinion that these have been so
general as maintained by these geologists. We are rather inclined to
believe, that the present inclined position of strata is in general
their original one;--an opinion which is countenanced by the known
mode of connection of strata, the phenomena of veins, particularly
contemporaneous veins, the crystalline nature of every species of
older rock, and the great regularity in the _direction_ of strata
throughout the globe.
The transition and flœtz-rocks also are much more of a chemical or
crystalline nature than has been generally imagined. Even sandstone,
one of the most abundant of the flœtz-rocks, occasionally occurs in
masses, many yards in extent, which individually have a tabular or
stratified structure; but, when viewed on the great scale, appear to
be great massive distinct concretions. These massive concretions,
with their subordinate tabular structures, if not carefully
investigated, are apt to bewilder the mineralogist, and to force him
to have recourse to a general system of subsidence or elevation of
the strata, in order to explain the phenomena they exhibit.
NOTE C, p. 13.
DELUGE.
There are many facts, some of which are recorded in the Bible, that
are hostile to Cuvier and De Luc’s opinions stated in the text,
viz. that the bed of the ocean was changed at the flood, or last
great catastrophe; and that the land, formerly occupied by animals,
was henceforth given up to fishes and other marine tribes. We are
told, for example, that the dove, which was sent forth from the ark,
found an olive-tree, whence it plucked a leaf, to carry back to the
patriarch, as a proof that the waters of the deluge were subsiding;
and we also find that the Assyrian rivers, which originally marked
the situation of Eden, retained the same geographical relations after
the earth had been repeopled. The natural history of the fossil
organic remains contained in alluvial deposits, is also in opposition
to the opinion of De Luc.
NOTE D, p. 19.
FORMATION OF PRIMITIVE MOUNTAINS.
Mitscherlich, in a memoir read before the Royal Academy of Berlin,
but not yet published, enters fully into the illustration of the
igneous origin of mountains, especially those of the primitive class,
deducible from his experiments on the formation of minerals by
fusion. As the view is interesting, we shall here give a short sketch
of it.
Have the primitive mountains of our globe, whose form necessarily
supposes a fluid state, been dissolved in water; or has the
temperature of our earth been raised to such a degree, that the
substances of which our primitive mountains are formed have become
fluid? This question has been differently answered, and the solutions
given have been attempted to be supported in proportion as the
observation of geological facts, and the inquiries instituted
with reference to the chemical combinations which compose the
earth, have been developed. New observations, and the discovery of
unknown laws in chemistry and mineralogy, must, at the same time,
open a new field for speculation and observation in geology. Of
the discoveries of our own times, there certainly is none which
has exercised a greater influence upon mineralogy than that of
determinate proportions, and especially the result of the researches
of Berzelius, that the chemical combinations which nature produces,
are formed according to the laws which he has discovered with regard
to artificial combinations; a result which has entirely changed the
aspect of this science, and has elicited a new system of mineralogy,
in which the natural-chemical combinations are ranked with those
which are artificial; which affords a confirmation to the laws of
crystallography, as being the same in both cases.
It has been objected to the truth of the position, that the laws
of natural combinations are the same as those which artificial
combinations follow; that chemistry can decompose minerals; but
that, in the formation of these combinations, natural laws have
been in activity, which art would in vain attempt to reproduce: but
this objection is groundless. The chemical affinity which acts in
artificial combinations is a power of nature, as well as the affinity
which regulates the composition of natural combinations: chemical
affinity, in general, is a quality of matter. In this objection,
modifying circumstances have been confounded with laws. The chemist
would very easily refute the objection, if he could compose minerals
of their elements, and produce artificial combinations similar in all
their characters to minerals themselves. From such researches, there
would, at the same time, be diffused a new light upon geological
investigations. In this manner many phenomena would be reproduced,
which have taken place at the formation of the earth; geological
observations would be repeated by experiments, which might be varied
at pleasure, for confirming these observations; and the recurrence
in nature itself would be sought of those phenomena which have been
produced in the laboratory;--inquiries, which are, however, of great
importance, because they may be arbitrarily disposed and arranged
according to the theory in view.
The importance of such attempts shew the value of any experiments
that go to prove the formation of minerals by artificial means; and
Mitscherlich has been very successful in detecting several mineral
species formed artificially.
Berzelius has shown, in his Chemical System of Mineralogy, that the
greater part of the chemical combinations of which our Earth is
composed, and especially the primitive mountains, are analogous to
salts and double salts; and that, in these combinations, the silica,
carbonic acid, and oxide of iron, act the part of acids; the silica
combines with the alumina, lime, magnesia, protoxide and peroxide
of iron, protoxide of manganese, potash and soda, forming, with
these bases, either simple salts, or double salts, in proportions
determined by the different degrees of saturation; the carbonic acid
is combined with the lime and manganese, and the peroxide of iron
with the protoxide.
The object which should be proposed in these attempts, of which we
speak, is to investigate the relation of these bases to the three
acids. We find ourselves fortunately seconded in this attempt by
a branch of national industry; for the complete extraction of the
greater number of metals depends upon the relation of the silica to
the above-mentioned bases, the degrees of saturation in which the
silica may occur with them, the greater or less degree of affinity
with which these bases combine with the silica, and, lastly, the
chemical qualities of the combination formed. It is necessary for
the metallurgist that he endeavour, in order to attain his object
completely, to produce, in proportion as the minerals differ,
different chemical combinations of the substances which compose
these minerals; but always in determinate proportions, either by
adding a foreign substance, or by regulating the fusion by the choice
of minerals. The combinations which the metallurgist thus produces,
are ordinarily minerals which have already been found in nature,
sometimes even new species.
During a journey in Sweden, Mitscherlich observed at Fahlun, where
he made inquiries regarding the ores, the scoriæ, and in general
regarding the extraction of copper, in order to form a correct idea
of this operation, not only some well-formed crystals in the scoriæ;
but also found that the whole mass of the slag had a crystalline
texture; and that the crystals, and the joints of the slags which had
a lamellar texture, remained the same at different periods of fusion,
provided only that the manner of operating of the metallurgist
remained the same. The examination of the crystalline figure of the
slag proved, that it was that of a mineral which has a composition
analogous to that of the slag. After having made this observation, he
found in almost every foundery which he visited in Sweden, different
crystalline combinations, which resembled minerals. Thus he found at
Fahlun, silicate and bisilicate of protoxide of iron; at Garpenberg,
mica, and several times augite and chrysolite. These combinations
have not only the same crystalline figures, but also all the other
characters of the corresponding minerals.
I have pursued these inquiries, says Mitscherlich, since my return
from Sweden; I have analysed the productions which I have found, and
the analysis has confirmed what the exterior had led to anticipate. I
have also augmented my observations by journeys in various districts
of Germany; and farther, I have been seconded in my researches by my
friends; so that I now possess upwards of forty different species of
crystallized chemical combinations produced by fusion, the greater
number of which are minerals already known; some are new species,
which have not hitherto been met with in nature.
The occurrence of mica, which forms a predominant constituent part of
our primitive mountains, as an artificial production, gave rise to
the following geological speculations.
The artificial production by fusion, of the minerals which compose
our primitive rocks, appears, according to Mitscherlich, to place
beyond doubt the theory that our primitive mountains were formerly
a melted mass. Such a state of fluidity, he continues, affords an
easy explanation of the figure of the Earth, of the increase of
temperature as we proceed into its interior, of hot springs, and of
many other phenomena. With respect to this theory, we may refer to M.
Laplace, who is convinced of its plausibility, without grounding his
belief upon the reasons which chemistry presents. I propose, however,
to make mention of a few facts, in order to shew with what facility
many chemical phenomena in geology may be explained by following this
theory.
Primitive mountains are generally distributed over the surface of the
earth: it necessarily follows that the bodies which have composed
the surface of the earth have participated of the temperature which
the primitive mountains have had at the period when they were in a
fluid state. The temperature at which water boils depends upon the
pressure of the atmosphere; and if the temperature of the earth
increases, we only require to diminish the mean height of the sea
32 feet, in order to have a pressure of an atmosphere more; and it
is by this pressure that the degree of temperature at which water
boils will also be raised higher. M. Laplace judges from the height
of the sea during flowing and ebbing, that the mean depth of the
sea is about 96,000 feet. Supposing three-fourths of this mass of
water were converted into vapour, the pressure of this vapour would
be nearly equal to 2250 atmospheres; and this pressure would so
augment the degree of heat at which water enters into ebullition,
that the primitive mountains might be in a state of fusion, without
the water with which they are covered being heated to the boiling
point; for the water which is not converted into vapour, and whose
quantity is a fourth of the whole mass of vapour, according to the
supposition which we have made, would cover the whole earth, because
water expands in increasing proportion if the temperature be raised,
and because the expansion of water is much greater than that of the
mass of our primitive mountains; and, consequently, according to
this supposition, our primitive mountains are formed, covered with
red hot water. The great pressure of so many atmospheres necessarily
modifies the reciprocal affinities of the substances which compose
the primitive mountains.
Primitive mountains are distinguished from volcanic productions in
this, that the lime and magnesia, which in them are combined with
carbonic acid, form with the silex silicates and bisilicates. It
is necessary that the silex, which, under the ordinary pressure,
and at an elevated temperature, expels the carbonic acid, exercise
no influence under the pressure of so many atmospheres; and it is
not surprising that crystals of quartz occur in Carrara marble.
In volcanic productions, this pressure no longer exists, and we
should find among these the same phenomena which our laboratories
and metallurgic operations present. Following this theory, the
circumstances that primitive mountains contain gypsum and carbonates,
and that water occurs in quartz, very readily admit of explanation.
And with regard to this latter phenomenon, the observations detailed
by Sir Humphry Davy afford an additional confirmation of the theory
in question.
We may explain in the same manner another phenomenon, which is more
in connection with the present state of our globe. Many observations
shew that the sea stood formerly at a much higher level than it does
at present. The water of the sea expands, if the temperature be
elevated more than the land. Admitting that the surface of the earth
has a temperature of 80° of Reaumur, and that the mean depth of the
sea may be 96,000 feet, the height of the sea would then be 4000 feet
higher than it is at present. If we suppose, as may be done without
committing any great error, that the expansion of the primitive
mountains is equal to that of glass, and that they have been at a
temperature of 200°, and even at a much lower one, the water of the
sea would cover the secondary mountains, in which we find the remains
of marine animals. This explanation of the former height of the sea
appears very simple, because the elevated temperature of the earth
may have resulted either from its original state of fluidity, or from
a geological revolution, which has destroyed, at the same time, the
organic beings of a former period.