THE LIBRARY
OF
THE UNIVERSITY
OF CALIFORNIA
DAVIS
The
Founders of Geology
By
Sir Archibald Geikie, F.R.S.
D.C.L.Oxf. ; D.Sc. Camb., Dubl. ; LL.D. Edin., Glasg., St. And.
Corr. Instit. France; Acad. Berlin, Vienna, Munich, Turin, Lincei, Rome,
Gottingen, Stockholm, Christiania, Belgium, Philadelphia, -
Boston ; Nat. Acad. Washington, etc.
Late Director-General of the Geological Survey of Great Britain and Ireland
Second Edition
London
Macmillan and Co., Limited
New York : The Macmillan Company
1905
A II rights reserved
First Edition (Extra Crown 8vo) 1897.
Second Edition, 8vo 1905.
GLASGOW : PRINTED AT THE UNIVERSITY PRESS
BY ROBERT MACLEHOSE AND CO. LTD.
PREFACE
IN the year 1896 the President of the Johns Hopkins
University, Baltimore, invited me to inaugurate the
Lectureship founded in that seminary by Mrs. George
Huntington Williams in memory of her husband, the
distinguished and widely regretted Professor of Geology
there. In accepting this invitation I chose for my
subject an outline of the history and development of
Geology during the period between the middle of the
eighteenth and the close of the second decade of the
nineteenth century an interval of about seventy years,
full of peculiar interest to students of the science, for
it was during that interval that the main foundations
of modern geology were laid.
In making this choice I was influenced by my
experience of the limited acquaintance with the his-
torical development of the science which has often
been shown even by those who have done good service
in enlarging its boundaries. English-speaking geo-
logists have for the most part contented themselves
with the excellent, but necessarily brief, summary of the
subject given by Lyell in the introductory chapters of
his classic Principles^ no fuller digest of geological
history having been published in their language. It
appeared to me that it might be useful to recount
vi Preface
the story of a few of the great pioneers during the
momentous period which I wished to select, and to
show, from their struggles, their failures, and their
successes, how geological ideas and theories arose, and
were step by step worked out into the forms which
they now wear.
The narrative thus proposed was made the subject of
six lectures which were published in the summer of
1897 as a small volume entitled The Founders of Geo-
logy. This work has been for some time out of print.
In preparing a new edition 1 have departed from the
original form of lectures, and from the restricted treat-
ment of the subject which a short course of lectures
necessarily involved. While retaining and also enlarg-
ing the more detailed discussion of the remarkable
period embraced in the original lectures, I have given a
sketch of the earlier progress of geological ideas, from
the times of ancient Greece onwards to the epoch that
formed the starting point of my former volume.
In this extension of the subject I have adhered to my
original plan of tracing the origin and slow develop-
ment of geological science, rather in an account of the
careers of a few of the chief leaders by whom the
progress has been mainly effected, than in an attempt
to summarise also the work of their less illustrious
contemporaries.
Since the publication of the first edition, my lamented
friend the late Professor Zittel of Munich published
(1899) his Geschichte der Geologic und Paldontologie a
work of extraordinary labour, fullness and accuracy,
with which no student of geology who cares to know
the history of his science can dispense. An excellent
Preface vii
abridged English translation of this voluminous treatise
has been prepared by Mrs. Ogilvie Gordon. The
scheme of treatment adopted by Professor Zittel,
however, differs so much from that which I have
followed that our two volumes may be regarded as
in large measure supplementary to each other. While
he has noted the contributions of all who have in any
important way advanced general or local geology, I
have selected for fuller consideration chiefly the lives
and work of some of the masters to whom we mainly
owe the foundation and development of geological
science.
November, 1905.
CONTENTS
CHAPTER I
Introduction. Geological ideas among the Greeks and Romans in
regard to (i) Underground forces ; (ii) Processes at work on the
surface of the earth ; (iii) Proofs of geological changes in the
Past, pp. 1-41
CHAPTER II
Growth of geological ideas in the Middle Ages Avicenna and the
Arabs. Baneful influence of theological dogma. Controversy
regarding the nature of Fossil Organic Remains. Early observers
^ in Italy Leonardo da Vinci, Falloppio, Steno, Moro. The
English cosmogonists Burnet, Whiston, Woodward. Robert
Hooke, John Ray, Martin Lister, Robert Plot, Edward
Lhuyd, - pp. 42-78^
CHAPTER III
Scientific Cosmogonists Descartes, Leibnitz. Speculations of De
Maillet and Buffon. Early illustrated works on fossil plants and
animals Lang, Scheuchzer, Knorr, Walch, Beringer, pp. 79-103
CHAPTER IV
The Rise of Geology in France Palissy. The labours of
Guettard, - pp. 104-139
CHAPTER V
The Foundation of Volcanic Geology Desmarest, - pp. 140-175.
x Contents
CHAPTER VI
The Rise of Geological Travel Pallas, De Saussure, - pp. 176-191
CHAPTER VII
History of the Doctrine of Geological Succession Arduino,
Lehmann, Fiichsel, Werner, - - pp. 192-236
CHAPTER VIII
The Wernerian School of Geology Its great initial influence and
subsequent decline. Effect of the controversy about the origin
of Basalt upon this School. Early history of Volcanic Geology.
" History of opinion regarding Earthquakes, - - pp. 237279
CHAPTER IX
The Rise of the modern conception of the theory of the Earth
Hutton, Playfair, - pp. 280-316
CHAPTER X
Birth of Experimental Geology Sir James Hall. Decay of
Wernerianism, - pp. 317-332
CHAPTER XI
The Rise of Stratigraphical Geology and of Palaeontology in France
Giraud-Soulavie, Lamarck, Cuvier, Brongniart, and Omalius
d'Halloy, pp. 333~377
CHAPTER XII
The Rise of Stratigraphical Geology in England Michell, White-
hurst, William Smith, Thomas Webster, the Geological
Society of London, W. H. Fitton. Early teachers and text-
books. Influence of Lyell, - - pp. 378405
CHAPTER I
INTRODUCTION. Geological ideas among the Greeks and Romans in
regard to (i) Underground forces ; (ii) Processes at work on the
surface of the earth ; (iii) Proofs of geological changes in the
Past.
IN science, as in all other departments of inquiry, no
thorough grasp of a subject can be gained, unless
the history of its development is clearly appreciated.
Nevertheless, students of Nature, while eagerly press-
ing forward in the search after her secrets, are apt
to keep the eye too constantly fixed on the way that
has to be travelled, and to lose sight and remembrance
of the paths already trodden. It is eminently useful,
however, if they will now and then pause in the race, in
order to look backward over the ground that has been
traversed, to mark the errors as well as the successes of
the journey, to note the hindrances and the helps which
they and their predecessors have encountered, and to
realise what have been the influences that have more
especially tended to retard or quicken the progress of
research.
Such a review is an eminently human and instructive
exercise. Bringing the lives and deeds of our fore-
runners vividly before us, it imparts even to the most
2 Introduction
abstruse and technical subjects much of the personal
charm which contact with strenuous, patient, and
enthusiastic natures never fails to reveal. Moreover,
it has a double value in its bearing on the progress
of those who are engaged in original research. A
retrospect of this kind leads to a clearer realisation
of the precise position at which they have arrived,
and a wider conception of the extent and limits of
the domain of knowledge which has been acquired.
On the other hand, by enabling them to comprehend
how, foot by foot, the realms of science have been
painfully conquered, it furnishes suggestive lessons as
to tracks that should be avoided, and fields that may
be hopefully entered.
In no department of natural knowledge is the
adoption of this historical method more necessary
and useful than it is in Geology. The subjects with
which that branch of science deals are, for the most
part, not susceptible of mathematical treatment. The
conclusions formed in regard to them, being often
necessarily incapable of rigid demonstration, must
'rest on a balance of probabilities. There is thus
room for some difference of opinion both as to facts
and the interpretation of them. Deductions and
inferences which are generally accepted in one age
may be rejected in the next. This element of
uncertainty has tended to encourage speculation.
Moreover, the subjects of investigation are them-
selves often calculated powerfully to excite the
imagination. The story of this Earth since it became
a habitable globe, the evolution of its continents,
birth and degradation of its mountains, the mar-
Introduction 3
vellous procession of plants and animals which, since
the beginning of -time, has passed over its surface,
these and a thousand cognate themes with which
geology deals, have attracted numbers of readers and
workers to its pale, have kindled much general interest,
and awakened not a little enthusiasm. But the records
from which the chronicle of events must be compiled
are sadly deficient and fragmentary. The deductions
which they suggest ought frequently to be held in
suspense from want of evidence. Yet with a certain -
class of minds, fancy comes in to supply the place
of facts that fail. And thus geology has been-
encumbered with many hypotheses and theories
which, plausible as they might seem at the time of
their promulgation, have one by one been dissipated
before the advance of fuller and more accurate know-
ledge. Yet before their overthrow, it may often be
hard to separate the actual ascertained core of fact
within them from the mass of erroneous interpreta-
tion and unfounded inference that forms most of
their substance.
From the beginning of its growth, geology has
undoubtedly suffered from this tendency to specula-
tion beyond the sober limits of experience. Its culti-
vators have been often described as mere theorists.
And yet in spite of these defects, the science has
made gigantic strides during the last hundred years,
and has gradually accumulated a body of well-ascer-
tained knowledge regarding the structure and history
of the earth. Few more interesting records of human
endeavour and achievement can be found than that
presented by the advance of this science. Little
4 Introduction
more than a century ago geology had no generally
acknowledged name and place in the circle of human
studies. At the present day it can boast a voluminous
literature, hundreds of associations all over the world
dedicated to its cultivation, and a state organization
in almost every civilized country for its systematic
prosecution. I propose to trace some of the leading
steps in this magnificent progress. Even speculations
that have been thrown aside, and theories that have
been long forgotten, may be found to have been
not without their use in promoting the general
advance.
If all history is only an amplification of biography,
the history of science may be most instructively read in
the life and work of the men by whom the realms of
Nature have been successively won. I shall therefore
dwell on the individual achievements of a few great
leaders in the onward march of geology, and indicate
how each of them has influenced the development of
the science. At the same time I shall trace the rise and
progress of some of the leading principles of the science,
which, though now familiar as household words, are
seldom studied in regard to their historical develop-
ment. Thus, partly in the life-work of the men, and
partly in the growth of the ideas which they promul-
gated, we shall be able to realise by what successive
steps geological science has been elaborated.
The subject which I have chosen, if treated as fully
as it might fitly be, would require a full course of
lectures or more than one printed volume. Within
the limits which I have prescribed to myself, I can only
attempt to present an outline of it. Instead of trying
Introduction
5
to summarize the whole history of geology, I think it
will be more interesting and profitable to pass somewhat
briefly over ancient and medieval time during which
geological ideas were crudely taking shape ; to dwell
rather fully on the labours of a few of the early masters,
who, by actual observation of nature and deduction
therefrom, laid the broad foundations of the science, to
touch only lightly on the work of some of their less
illustrious contemporaries, and to do little more than
allude to the modern magnates whose life and work are
generally familiar. I have accordingly selected for
fullest treatment, in this volume, what has been called
the Heroic Age of geology, or the period which extends
from the middle of the eighteenth to the earlier decades
of the nineteenth century, an interval of about seventy
years. A few later conspicuous names will require
some brief notice in order to fill up the general outlines
of our picture.
The most casual observation is now-a-days sufficient
to convince us that the surface of the earth has not
always been as it is to-day. At one place sheets of
sand and gravel point to the former presence of running
water, where none is now to be seen. Elsewhere shells
and other marine organisms underneath the soil show
that the dry land was formerly the bed of the sea.
Masses of sandstone, conglomerate and limestone, once
evidently laid down in horizontal layers on the sea-
bottom, but now hardened into stone, disrupted, placed
on end, and piled up into huge hills and mountain-
ranges, prove beyond all question to our modern eyes
that stupendous disturbances attended the conversion
of the sea-floor into land.
6 Introduction
A few of the simpler and more striking of these
features might attract notice even among the earliest
and rudest tribes. But still more would the elemental
forces of nature arouse the fears, excite the imagination
and stimulate the curiosity of primitive man. Wind
and lightning, rain-storms and river-floods, breakers
and tidal waves, earthquakes and volcanoes would seem
,\> be direct and visible manifestations of powerful but
" unseen supernatural beings. Nor would the more
obtrusive features of landscape fail to add their
influence mountains with their clouds, tempests and
landslips ; crags and precipices with their strange
grotesque half-human shapes, ravines with their gloomy
cliffs and yawning chasms between.
It is not difficult to conceive how from these con-
- current materials there would spring fables, legends and
myths, long before the spirit of scientific observation
and deduction was developed, and how such fables might
continue to satisfy the popular imagination long after
that spirit had arisen among the more reflective few.
The earliest efforts at the interpretation of nature found
their expression in the mythologies and cosmogonies
of primitive peoples, which varied in type from country
to country, according to the climate and other physical
conditions under which they had their birth. Geo-
logical speculation may thus be said to be traceable
in the mental conceptions of the remotest pre-scientific
ages.
The popular beliefs continued for a time to influence,
in a greater or less degree, the speculations of the
philosophers who began to observe the operation of
natural processes and who, though their deductions
Geology of Greeks and Romans 7
were often about as unscientific as the myths for which
they were substituted, may yet be claimed as the
earliest pioneers of geology. The first stages of
advance in theoretical opinions on these subjects may
best be illustrated by a brief survey of the geological
ideas to be found scattered through the literature of
Greece and Rome.
Among the poets allusions abound to the popular
interpretations of geological phenomena, wherein the
influence of gods and heroes in altering the face of
Nature became the subject of legend and myth. It
is interesting to note the progress of the decay of
these ancient superstitions and their replacement by
more natural explanations, based upon actual obser-
vation of the present order of things. As an example
of this transition, reference may be made to the various
attempts to account for the remarkable defile of Tempe,
which was one of the marvels in the scenery of Greece.
The wide mountain-girdled plain of Thessaly was
popularly believed to have once been covered with
a lake which was ultimately drained by the kindly
intervention of Poseidon, who himself split open the
gorge in the encircling rocky barrier, whereby a passage
was given for the escape of the stagnant waters to
the sea. Later generations attributed the friendly act
to Hercules. By the time of Herodotus, however,
(B.C. 500) the supernatural had given way, in the minds
of reflective men, to a natural interpretation* of such
features. Yet the Father of History, as was natural
to his pious and reverential spirit, does not scornfully
reject the long established belief. " That the gorge
of Tempe, 7 ' he says, " was caused by Poseidon is
8 Strabds Scepticism
probable ; at least one who attributes earthquakes and
chasms to that god would say that this gorge was
his work. It seemed to me to be quite evident that
the mountains had there been torn asunder by an
earthquake." l
By the beginning of our era, supernatural inter-
pretations of geological features had still further gone
out of fashion among the writers of the day, and it-
was now thought unnecessary even to allude to them.
Strabo (B.C. 54 A.D. 25) simply refers the Vale of
Tempe to the effects of an earthquake, as if its origin
were so manifest as to offer no reasonable ground
for any doubt. In no respect do the writings of this
geographer differ more conspicuously from those of
Herodotus than in their attitude towards the myths
of the olden time. The difference no doubt marks
the general progress of public opinion on the subject
in the course of five centuries. Strabo usually passes
over the legends in silence, and when he takes occasion
to refer to them, it is not infrequently to reject them
with contempt. He will not believe the story that
the River Alpheus flows under the sea and rises again
to the surface as the fountain of Arethusa at Syracuse,
and the reasons which he gives for his refusal are such
as a modern man of science might use. 2 Referring
to a statue at Siris, in Southern Italy, which was alleged
to have been brought from Troy after the siege and
to have closed its eyes when certain suppliants were
forcibly dragged away from its shrine, he sarcastically
remarks that some amount of courage is required to
believe this tale, and also to admit that so many statues
1 Book vii. 129. 2 vi, ii. 4.
The Mediterranean Basin 9
could have been brought from Troy as were so
reputed. 1 He states that while at the Memnonium
at daybreak, he certainly heard a noise, but whether
it came from the statue or was made by some of the
company, he could not tell, though he was disposed
to believe anything rather than that stones themselves
emit sound. 2 He even carries this critical spirit into
his account of alleged historical events, as where, in
ridiculing the statement that the Cimbri were driven
out of their territory by an extraordinarily high tide,
he appeals to the known regularity and periodicity
of the tides, as a natural, harmless and universal
phenomenon, which disproves such tales. 3
In considering the opinions of the Greeks and
Romans relative to the origin of the various features
of the external world, it is well to note that the nations
gathered together in the vast basin that drains into
the Mediterranean Sea were placed in an exceptionally
favourable position for having their attention drawn
to some of these features. In particular, this region
displays with remarkable fullness the operation of
various natural agencies whereby the surface of the
earth is altered. It reveals also in a striking manner
to the observant eye proofs that these agencies have
been at work from a remote antiquity, and have in the
course of ages profoundly modified the distribution of
sea and land. Thus the countries situated within its
borders have been and still are subject to continual
shocks of earthquake. For many thousands of years
probably not a month has passed without a concussion
in some part of the region, usually slight enough to
1 vi. i. 14. 2 xvn. i. 46. 3 vii. ii. I.
io The Mediterranean Basin
alarm without doing much damage, but ever and anon
as appalling calamities that have prostrated cities and
destroyed thousands of their inhabitants. Moreover
another phase of subterranean energy has from time
immemorial been conspicuously developed in the same
region. Two distinct and widely separated volcanic
centres exist in the Mediterranean basin, and have had
their eruptions chronicled by poets and historians from
a remote antiquity. One of these centres lies in the
Aegean Sea, where the isle of Santorin still remains an
active volcano. The other and much the more im-
portant area extends from the Phlegraean Fields around
Naples to beyond the southern coast of Sicily, and
includes the great cones of Etna and Vesuvius, besides
other smaller but active vents. From the dawn of
history the inhabitants of Greece and Italy have wit-
nessed the awe-inspiring eruptions of these volcanoes
which notably coloured some parts of the old myth-
ology.
Again, the Mediterranean region contains within its
limits a remarkable diversity of climates, and con-
sequently a varied and abundant development of all
those geological processes over which climate exerts a
controlling influence. The mountain chains, from the
^ifar Pyrenees on the one hand to the distant Caucasus
on the other, with their snow-fields and glaciers, their
cloud-caps and storms, display the extremes of winter
cold, and of rainfall, tempests and landslips. On the
southern side of the basin lie wide tracts of country
with little or no rain, and passing inland into vast
sandy deserts of almost tropical heat. From the
mountains innumerable torrents gather into lakes and
The Mediterranean Basin 1 1
rivers, which water the plains and bear the drainage
out to sea. Drought and inundation succeed each
other, and the same river which at one time carries
fertility all over its valley, at another time, swollen
into an impetuous flood, spreads across the plains,
sweeping away farms and villages, and burying the
soil under sheets of sterile gravel and sand. The
operations of such streams as the Rhone, the Po,
the Tiber, the Danube, the Achelous and the Peneius
were not only watched by the inhabitants along their
banks but became the subjects first, of widely diffused
legendary tales, and afterwards of philosophical dis-
cussion. On the south side of the great sea, the
Nile, with its mysterious sources and its unfailing /
annual rise, furnished an inexhaustible source of wonder J
and speculation.
Further, all round the basin of the Mediterranean
the younger geological formations, upraised from the
sea, now underlie many of the plains and rise high
along the flanks of the hills. In these deposits, shells
and other remains of sea-creatures have been preserved
in such vast numbers as could not fail to arrest atten-
tion even in the infancy of mankind. Since the
organisms are obviously like those still living in the
neighbouring sea, the inference could readily be
drawn that the sea had once covered the tracts of
land where these remains had been left. This con-
clusion was reached by some of the earliest Greek
philosophers, and there can be little doubt that it
led to those wide views of the vicissitudes of Nature
which were adopted in later centuries by their
successors.
12 Aristotles Views of the Universe
Our retrospect of the growth of an intelligent
appreciation of the geological phenomena so well
developed in this long inhabited region need not
take us further back than the time of Aristotle, the
true Father of Natural History, (B.C. 384-322) who
besides his own original contributions to science,
supplies valuable references to writings of his pre-
decessors which have not come down to us. His
treatises furnish an admirable exposition of the state
of natural knowledge in his time. When he wrote,
the geocentric view of the universe was still publicly
accepted without question. But he had firmly grasped
certain truths regarding our globe, which, though
taught long before by some of his predecessors, were
not yet generally admitted. Thus he recognized that
the planet possesses a spherical form, which is the
most perfect of all, and he pointed in proof to the
round shadow cast by the earth upon the moon during
a lunar eclipse. He showed also by the difference in
the aspect of the stellar heavens, as we move but a
little way from north to south or south to north, that
the mass of our globe must be relatively small. " The
size of the earth is nothing," he says, u absolutely
nothing, compared with the whole heavens. The
mass of the sun must be far greater than that of our
globe, and the distances of the fixed stars from us is
much greater than that of the sun." 1 Accepting the
common belief that the world consisted of four
elements, he looked on these as arranged according
to their relative densities. " The water is spread as
an envelope round the earth ; in the same way, above
1 MeteoricSy i. viii. 6 ; xiv. 1 8.
Aristotle on Earthquakes 13
the water lies the sphere of air, while outside of all
comes the sphere of fire." 1
With regard to the surface of the planet, Aristotle
had formed some sagacious conclusions, though mingled
with certain of the misconceptions that were prevalent
in his time. In trying to gain a general impression of
the manner in which geological problems were treated
by him and the succeeding naturalists and philosophers
of antiquity we may find it convenient to consider
them under the three sections of (i) Underground
processes ; (2) Surface processes ; and (3) Evidence
of geological changes in the past.
i . Underground Processes. As Greece, from its special
geological structure, has from time immemorial been
subject to frequent earthquakes, the attention of the
more reflective men in the country must have been
early drawn to these subterranean disturbances and to
a consideration of their possible cause. Aristotle has
devoted a portion of his treatise on Meteorics to a
discussion of earthquakes, and has quoted the opinions
of some earlier philosophers in regard to them. He
tells us that Anaxagoras (B.C. 480) accounted for these
disturbances by the descent of the surrounding ether
into the depths of the earth ; that Democritus (B.C.
460-357) thought they were caused by the bursting
out of the mass of liquid within the earth, especially
after heavy rains ; and also, after the earth had become
desiccated by the great commotion arising from the fall
of water from the full spaces into those that were
empty ; and that Anaximenes (B.C. 544) supposed
1 Op. cit. ii. ii. 5. The sphere of fire, the "flammantia moenia
mundi" of Lucretius, was the region of the stars and planets.
14 Aristotle on Earthquakes
them to be produced by the disruption of mountains
when the earth, at first full of water, dries up ; for
he remarked that they take place chiefly during
droughts and also during excessively wet seasons,
because in the one case the earth is dried and splits
up, while in the other, it gives way on account of
being saturated with liquid.
Rejecting the explanations of his three predecessors
just cited, Aristotle remarks that if some of their
views were true, earthquakes ought gradually to grow
less abundant and severe, until at last the earth should
cease to shake, but that as this diminution has not been
observed, another interpretation must be sought. He
accordingly proposes one of his own which is a curious
and memorable instance of imperfect observation and
inaccurate generalisation. Earthquakes are due, he
thinks, to a commingling of moist and dry within the
earth. Of itself, the earth is dry, but from rain it
acquires much internal humidity. Hence when it is
warmed by the sun and by the internal heat, wind is
produced both within and without its mass. Wind,
being the lightest and most rapidly moving body, is
the cause of motion in other bodies ; and fire, united
with wind, becomes flame which is endowed with great
rapidity of motion. It is neither water nor earth
which causes an earthquake ; it is the wind when
what is vaporised outside returns into the interior.
Remarking a relation between the frequency and
violence of earthquakes and the state of the weather,
Aristotle admits with Anaximenes that they occur most
abundantly in spring and autumn, during the seasons
of heavy rain and of great drought, but he thinks
Aristotle on Volcanoes 15
that the reason of this relation should be sought in
the fact that during these seasons there is most wind. 1
Aristotle regarded earthquakes and volcanic erup-
tions as closely related phenomena. He states that it
had been observed in some places, that an earthquake
has continued until the wind from the interior has
rushed out with violence to the surface, as had
then recently happened at Heracleia on the Euxine,
and before that event at Hiera (Volcano), one of the
Lipari Isles. At this latter locality the ground rose
up with a great noise and formed a hill that broke
up and allowed much wind to escape from the fissures,
together with sparks and cinders which buried the
whole of the neighbouring town of the Liparans.
The shock was even felt in some of the towns on
the opposite mainland of Italy.
Aristotle was further led to propose an explanation
of the great heat that forms part of the volcanic
phenomena. c ' The fire within the earth," he remarks,
" can only be due to the air becoming inflamed by
the shock, when it is violently separated into the
minutest fragments. What takes place in the Lipari
Isles affords an additional proof that the winds circu-
late underneath the earth." 2
This idea that volcanic action was mainly due to
the movement of wind imprisoned within the earth
obtained wide credence in antiquity. Aeolus, the god
of the winds, was believed to have his abode under
the so-called Aeolian Isles, which are all of volcanic
origin, and among which eruptions have been taking
place since before the dawn of history.
1 Meteor. 11. vti., viii, 2 O/>. clt. n. viii. 20.
1 6 Lucretius on Earthquakes
Aristotle in his wide survey of the organic and
inorganic kingdoms did not omit to consider the
nature of stones, metals and minerals, and to offer
his suggestions as to their possible origin. He sup-
posed the existence of two exhalations which play a
notable part in nature both inside and outside the earth.
One of these, the smoky or dry exhalation by burning
substances, gives rise to minerals and other kinds of
stone which are insoluble in water. The other or
vaporous exhalation produces the metals which are
fusible or ductile. Aristotle's favourite pupil, Theo-
phrastus (6.0.374-287) took up this subject in a
much more practical way in his tract on Stones, which
describes the external characters, sources and uses of
the more familiar rocks and minerals. Interesting as
a narrative of what was known and thought in his
day in regard to the mineral kingdom, it may be
claimed as the earliest essay in Petrography. His
treatise " On Fishes " contains a reference to remains
of fishes found in the rocks of Pontus and Paphla-
gonia. The philosopher thought that these fossils
were developed from fish-spawn left in the earth, or
that fishes had wandered from neighbouring waters
and had finally been turned into stone. He also
expressed the idea that a plastic force is inherent in
the earth whereby bones and other organic bodies are
imitated.
Lucretius, whose great poem, De Rerum Nafura,
appeared about half a century before the beginning
of our era, states with his characteristic force the
explanations then in vogue to account for the pheno-
mena of earthquakes. The interior of the earth,
Lucretius on Volcanoes 17
he declares, must be full of wind-swept caverns, with
lakes, rivers, chasms and cliffs, as above ground. The
fall of some of these vast mountainous rocks, under-
mined by time, gives such a shock as to send gigantic
tremors far and wide through the earth. Again,
wind, collecting in these subterranean cavernous spaces,
presses with such enormous force against the walls
towards which it rushes as to make the earth lean
over to that side, and to topple down buildings
above ground. Sometimes the air, either from out-
side or from within, sweeps with terrific whirling vio-
lence into the vacant spaces underneath, until in its
fury it cleaves for itself a yawning chasm in the earth
by which it escapes to the daylight. Even when it
does not issue at the surface, its violence among the
many underground passages sends a tremor through
the earth.
The poet stating that he will explain how volcanic
eruptions, such as those of Etna, arise, declares that
the mountain is hollow within and that the wind and
air inside, when thoroughly heated and raging furiously,
heat the rocks around. Fire is thus struck out from
these rocks and with its swift flames is swept by the
air up the chasms, until it issues from the mountain-
top, hurling forth ashes, huge stones, and black smoke.
From the sea- floor caverns reach down into the depths
of the mountain, and the water that enters there,
mingled with air, rushes out again in blasts of flame
with showers of stones and clouds of sand. 1 We
are not definitely told, however, by what process the
heat inside is engendered, whether the explanation
1 Z)<? Rerum Natura, vi. 535-702.
B
1 8 Sir abet s 'Geography'
of Aristotle was favoured, or the common belief in
subterranean accumulations of sulphur and other com-
bustible substances.
Coming down to the beginning of the Christian era,
we turn to the pages of Strabo, who besides availing
himself of the labours of his predecessors, more
particularly of those who wrote in Greek, travelled over
a considerable part of the ancient world, with observant
eyes as to what he himself saw and a critical judgment
as to what he heard from others. Though his great
work is mainly a description of the topographical and
political geography of his day, it is interspersed with
acute observations and reflections regarding the
physical features of the various countries, and the
natural processes whereby these features have been
produced or altered. His Geography^ therefore, con-
tains not a few important statements of fact in regard
to the general effects of subterranean energy. Thus
he cites a number of earthquakes by which chasms
in the ground were formed, thousands of people were
destroyed and cities were swallowed up. He also
gives some information regarding volcanic eruptions
which had taken place within the historical period
in the Mediterranean region. In his time Mount
Vesuvius was not only quiescent, but was not known
to have ever been active. His quick eye, however,
detected the true origin of the mountain. From
the aspect of its summit, he inferred that it was
once a volcano, with live craters which had become
extinct on the failure of the subterranean fuel, and
he compared its slopes to the ground around Catania,
where the ashes thrown out by Etna have formed
Strabds Ideas of Volcanoes 19
an excellent soil for vines. He recognised the truly
volcanic nature of the whole district from Etna to
the Phlegraean Fields, under which Typhon, as Pindar
sang, lay crushed on his burning bed. 1 In his excellent
account of the ascent of Etna, Strabo compares the
molten lava to a kind of black mud which, liquefied in
the craters, is ejected from them and flows down the
sides of the mountain, cooling and congealing in its
descent, until it becomes a motionless dark rock like
millstone. 2
Strabo, however, made no advance on his predecessors
in regard to an explanation of the nature and cause
of volcanic action, which he continued to attribute to
the force of winds pent up within the earth. He
alludes to the connection between the state of the
weather and volcanic energy at the Lipari Isles, already
noticed by previous writers a connection which, so
far as it exists, doubtless tended to confirm the popular
attribution of the eruptions to the escape of subterranean
wind. The most important remark of this geographer
in regard to volcanic action is undoubtedly his obser-
vation that the district around the Strait of Messina
seldom suffers much from earthquakes, whereas
formerly, before the volcanic orifices of this region
were opened up, so as to allow of the escape of the
fire smouldering within the earth and of the im-
prisoned wind, water and burning masses, the ground
was convulsed with frightful earthquakes. The
doctrine that volcanoes are safety valves, which was
once thought to be a modern idea, is thus at least
as old as the beginning of the Christian era.
iRook vi. i. 5. 2 vi. ii. 3, 8.
20 Strabo on Origin of Islands
Strabo cites examples of wide-spread and also local
sinkings of land, as well-known historical events, such
as the catastrophe that submerged the town of Helice
in Achaia, together with an extensive surrounding
district. He believed that to earthquakes and similar
causes were due the risings, slips and other changes
which at various times affect the surface of the earth,
and he held that deluges, earthquakes, eruptions of
wind, and elevations of the bottom raise the level of
the sea, which on the other hand, is lowered when
the bottom subsides. 1
The numerous islands in the Mediterranean Sea
occupied much of Strabo's attention. He appears
to have believed that their insular character arose from
two causes. Some he supposed to have been torn
from or joined to the mainland by such convulsions
as earthquakes, while others were obviously thrown
up by volcanic agency. Those which lie off headlands
he was inclined to attribute to the former cause ;
but those which stand in the middle of the sea seemed
to him to have been most probably thrown up from
the bottom. He does not appear, however, to have
had any settled grounds of belief upon this question,
for in one passage he speaks of Sicily having been
broken off from the mainland of Italy by earth-
quakes, 2 while elsewhere he thinks that this island
" may have been thrown up from the bottom of
the sea by the fires of Etna, as the Aeolian and
Pithecusan Isles (Ischia, etc.) have been." 3 He refers
to submarine eruptions among the Lipari Islands
that had given rise to islets or shoals of hard rock
1 Book i. iii. 10. 2 vi. i. 6. 3 i. iii. 10.
Seneca s 'Natural Questions' 21
an interesting observation in connection with some
events in the recent history of this volcanic dis-
trict. 1
The philosopher Seneca, besides the treatises and
plays by which he is chiefly known, wrote towards the
end of his life a tract in which, under the title of
Natural Questions, he discoursed largely of the heavenly
bodies and of meteorological phenomena, and discussed
also, more fully than any previous writer whose work
has come down to us, some of the more important
geological processes of nature. He was born a few
years before the commencement of our era and met his
tragic fate in A. D. 65. As the tract in question refers
to events which had happened some time before, in the
spring of A.D. 63, it is probably his latest work.
Seneca appears to have been familiar with all the
literature of the subject up to his own time, and he
quotes and criticises the opinions of many of his
predecessors. Especially interesting are his disquisi-
tions on the flow of water at the surface and below
ground, and on the results and origin of earthquakes.
From his treatment of these matters he can be seen to
have been a shrewd observer and sagacious reasoner,
though still unable to advance much beyond the
opinions prevalent in his day, and still holding to some
of the most erroneous popular beliefs. Yet he clearly
recognized that the system of Nature is no capricious
series of events, liable at any moment to be interrupted
and changed by the fiat of some irascible divinity.
" Though the processes below ground," he remarks,
" are more hidden from us than those on the surface
22 Seneca on Earthquakes
of the earth, they are none the less equally governed
by invariable laws."
Seneca appears to have been much impressed by the
earthquake which did so much damage in Campania on
5th February A.D. 63, for he refers to it again and
again, and furnishes from the lips of eye-witnesses some
interesting particulars regarding it. Thus he tells how
a flock of 600 sheep were killed in the district of
Pompeii, a fate which he attributes to the rise of
pestilential vapours from the ground. He was in-
formed by a most learned and serious friend that when
he was in the bath the tiles on the floor were separated
from each other and were then driven together again,
while the water at one moment sank through the
opened joints of the pavement, and thereafter boiled up
again and was jerked out. The philosopher's account
is the earliest detailed description of an earthquake,
which has come down to us. The recentness of the
event, the serious nature of the damage done, and the
abundant narratives of those who had been in the midst
of the calamity led him to consider the effects and
causes of earthquakes more at large than had been done
before his time.
After giving a graphic picture of the terror of the
human mind when the ground beneath our feet is
convulsed, and the one thing in the world that seemed
securely fixed gives way beneath us, he ridicules the
action of those who from fright deserted Campania and
vowed they would never return. Where, he asks, can
they promise themselves to find a more steadfast soil? 1
1 Little did he realise the volcanic nature of the ground and the
potential possibilities of destruction which were to be manifested
Seneca on Earthquakes 23
We run the same risks everywhere, for no part of the
wide earth is immovable. He then proceeds to
enumerate the various explanations that up to his day
had been proposed to account for the phenomena.
Among these he cites that of Anaximenes as to the
collapse of subterranean portions of the earth. But he
himself adheres to the view which had now been
adopted by the majority of authors, including those
of most weight, who supposed the cause to lie in
the movements of wind imprisoned beneath the earth.
He offers a long disquisition on the manner in which
he conceives that the subterranean wind acts. Nothing
known to us, he states, is more powerful or more
penetrating than air in motion. Without its aid none
of the other forces in nature, even those which are
most energetic, are of any avail. As beneath the
earth there are abundant hollows, with rivers, lakes
and large bodies of water, which have no exit above
ground, so in these dark caverns and recesses the
heavy air is pressed down and by its motion gives
rise to currents of wind. The force of these currents
is increased in proportion to the impediments in the
way of their escape, until they find a vent to the
surface.
Seneca distinguishes between the up-and-down move-
ment (sttccussio) in earthquakes and the oscillatory
movement (indinatio) like that of a ship at sea. He
thinks that even a third kind of motion should be
recognised, that of trembling or vibration. He
only sixteen years after the Campanian earthquake by the outbreak
of Vesuvius in A.D. 79, and the overwhelming of Pompeii and
Herculaneum.
24 Seneca on Volcanoes
believes that each of these motions arises from a
different cause. Thus the trembling or vibratory
phase, like that produced by the passage of a heavily-
laden wagon, or like that arising from a landslip, may
be due to the collapse of the sides of subterranean
cavities, when the rocks fall with great weight and
noise into the recesses below. These catastrophes may
sometimes be aided by the abrading power of the
overlying rivers, and the constant action of water in
widening and weakening the fissures of rocks. When
the concussion is so great as to shake down the walls
by which the roof of one of these underground empty
spaces is supported, the whole ground will give way and
sink into the abyss, carrying down large tracts of the
surface and even entire cities.
This philosopher recognized the local character of
earthquakes, and connected the limitation of their
extent with the restricted dimensions of the subter-
ranean caverns where the wind is developed. If it
were not so, he remarks, wide tracts of country would
be agitated and many places would totter at the same
time. But the movement never extends beyond a
distance of two hundred Roman miles, and he points
once again to the recent example that had filled the
Roman world with its renown, yet did not itself travel
outward beyond the bounds of Campania.
Volcanoes form the subject of some interesting
remarks in Seneca's treatise. He refers to various
eruptions in the Italian and Greek centres of volcanic
activity. In speaking of two outbreaks at Santorin
he remarks that an island rose out of the sea by
protracted eruptions from below, and he notes that
Seneca on Volcanoes 25
the internal fire is neither extinguished by the
weight of the superincumbent depth of sea, nor pre-
vented from rushing to a height of a couple of
hundred paces above the water. 1 He speaks of Etna
having sometimes abounded in much fire, and thrown
out a great deal of burning sand, day being turned
into night, to the terror of the population. On such
occasions, thunder and lightning are said to have
abounded ; but these came from the concourse of
dry materials, and not from ordinary clouds, of which
probably there were none in such a raging heat of
air a shrewd anticipation of the modern distinction
between ordinary atmospheric electric discharges and
those evoked during the ejection of vapours, gases,
dust, and stones from a volcanic orifice. 2
Following the general opinion of the learned men
who had preceded him, Seneca had no doubt that
volcanic eruptions, like earthquakes, were due to the
struggles of subterranean wind to break out to the
surface. It is evident, he says, that underground
there is a great store of sulphur, and of other sub-
stances not less capable of combustion. When the
subterranean wind in seeking an outlet has whirled
itself through these places, it must in so doing set
these inflammable things on fire by mere friction.
The flames spreading, in spite of the somewhat
sluggish air, make way with vast noise and force,
and find at last their escape to the surface, as at
Etna and elsewhere. There are fires covered up
within the earth, some of which occasionally burst
forth ; but a vast number are always burning in
1 Book ii. xxvi. 5. 2 n. xxx. i.
26 Pliny s 'Natural History'
concealment. 1 As the result of these subterranean
commotions, new mountains are raised and new
islands are placed in the midst of the sea. " Who
can doubt, for instance," the philosopher asks, " that
wind gave birth to Thera and Therasia, and to the
younger island which even in our own time we have
seen spring up in the Aegean sea ? "
Another work of Seneca's time deserves mention
here the voluminous Natural History of the Elder
Pliny, in which so vast a mass of miscellaneous notes
has been compiled regarding the plants, animals, and
minerals known to the ancients, and the earthquakes,
volcanic eruptions, inundations and other natural
events which had happened within the times of
history. 2 Though rather a chronicler of other men's
opinions and experiences than himself an original
observer, he must have been imbued with a keen
interest in every department of Nature, as he cer-
tainly was endowed with portentous and unwearied
industry in gathering together all the information
that could be ascertained from every source. The
graphic picture which we have of him in his nephew's
letters to Tacitus shows him as the eager and
enthusiastic naturalist, keenly interested in every
phenomenon, ready with his tablets to make a note
of all that he saw or heard or read, and strictly
methodical and austerely temperate in his habits of
1 Book v. xiv. ; 11. x. 4.
2 Those who are interested in such matters will find a useful
compendium of Pliny's remarks on minerals, rocks, earthquakes
and volcanoes in Dr. H. O. Lenz's Mineralogie der Alten Gricchen
und Romer, Gotha, 1861.
Pliny on Earthquakes 27
life. It must always be remembered that it was in
the pursuit of scientific knowledge that he lost his
life by venturing too near the scene of the disastrous
eruption of A.D. 79, which overwhelmed Herculaneum
and Pompeii. If the tradition be correct that Empe-
docles met his death by approaching too close to the
edge of the crater of Etna, this philosopher may
perhaps be claimed as a victim to the desire to
explore the mysteries of volcanic action. But in the
case of Pliny there is no uncertainty. He is enrolled
for all time as the first definitely recorded martyr to
the cause of geological science.
After referring to the opinion of the Babylonians
that earthquakes and all allied phenomena are to be
ascribed to the influence of the stars, Pliny remarks :
" My own belief is that they are caused by wind.
They only occur at times of complete calm, when
the wind, having sunk down into the subterranean
chasms, breaks forth once more." J He enumerates
a number of earthquakes of note, and in discussing
the phenomena that take place in connection with
them on land and sea, he states that towns with
numerous culverts and houses with cellars suffer less
than others, and that, for example in Naples, those
houses are most shaken which are built on hard
ground. He likewise recounts instances of volcanic
eruptions and the appearance of new volcanic islands,
but without throwing any light on the causes of
these disturbances.
It thus appears that during classical antiquity no
perceptible advance had been made in the investigation
1 Hut. Nat. ii. 8 1.
28 Herodotus and Aristotle on Rivers
of the nature and cause of earthquakes and volcanoes.
The idea that both of these manifestations of hypogene
energy arise from the action of air imprisoned within
the earth and struggling to escape continued to hold
its ground, the heat and fire of volcanoes being re-
garded as probably due to the action of the internal
wind in setting fire to sulphur, bitumen or other
combustible substances.
2. Processes at work on the surface of the earth.
Among the geological agents which alter the face of
the land, rivers have naturally occupied much of the
attention of mankind in all ages. Herodotus during
his visit to Egypt was greatly interested in the Nile,
and he devotes some space to a discussion of the
remarkable characteristics of this stream. He enum-
erates and criticises the various explanations which had
been given of its annual rise, but without venturing
on any definite conclusion himself. He recognises
however the significance of the yearly deposit of silt
on the surface of the country, and concludes that
u Egypt is the gift of the river."
Aristotle discusses the phenomena presented by rivers,
and shows considerable acquaintance with the drainage
system on the north side of the Mediterranean basin.
He criticises previously expressed opinions as to the
source of rivers, particularly ridiculing the sugges-
tion of Plato that all rivers flow directly from a vast
mass of water under the earth. He appears to have
held the opinion that just as the vaporised moisture
in the atmosphere is condensed by cold and falls in
drops of rain, so the moisture beneath the earth is
similarly condensed and forms the sources of rivers.
Strabo on Rivers 29
He states that the mountains, by their cold tempera-
ture, condense the atmospheric moisture and receive
a vast quantity of water, so that they may be com-
pared to an enormous suspended sponge. He shows
by geographical illustrations, drawn from Asia and the
Mediterranean basin, that the largest rivers descend
from the loftiest ground, where the water accumu-
lates in numberless channels. He admits the possible
existence of underground lakes from which rivers may
issue, and alludes to the disappearance of some streams
into subterranean channels.
Aristotle, moreover, reflected profoundly on the
geological operations of rivers. Recognising the
truth of the observation that the plain of Egypt had
been built up by the deposits of the Nile, he also
noted that along the shores of some parts of the
Black Sea the river alluvia had increased so much
in sixty years that the vessels in use there had to
be much smaller than formerly, and that in this case,
as in so many others, the silting up might go on
until the marsh-land became dry ground. Similar
changes were then in progress on the Bosphorus.
The contemplation of these and other vicissitudes led
the philosopher to some striking generalisations as to
the past and the future of the surface of our globe,
to which reference will be made on a later page.
To Strabo we are indebted for some sagacious
observations on the hydrography of the Mediterranean
basin. He points out that, like the Nile, the other
rivers that enter this sea form extensive alluvial
deposits at their mouths, as well as inland over the
low grounds, and he specially instances the plains of
30 Seneca on Water-Cimilation
the Hermes, Cayster, Maeander and Caicus as having
been formed by the streams that flow through them. 1
The deltas vary, he thinks, according to the nature
of the regions drained, being most developed where
the country is large and the surface rocks are soft,
and where the rivers are fed by many torrents. He
remarks that these accumulations are prevented from
advancing further outward into the sea by the ebb
and flow of the tides. 2
Strabo believed the outflowing currents of the
Mediterranean Sea, as well as that of the Bosphorus,
to be due to the escape of the surplus water that
drains into the basin. In the course of his narrative
he is led to discuss the question of the opening of
a connection between the Black Sea and the Medi-
terranean, and between this latter and the outer
ocean. He expresses the opinion that we should not
be surprised if the Isthmus of Suez were to be dis-
rupted or to subside, so as to allow the Mediterranean
and Red Sea to be joined together. 3
In his philosophical survey of Nature and its pro-
blems, Seneca found room for a consideration of the
water-circulation of the globe. His reflections on this
subject show that in one important respect he had
not advanced beyond the position of Aristotle. In
his essay already cited he discusses at some length
the various kinds of terrestrial waters, noting their
tastes, temperature, uses, effects and other features.
He speaks of himself as a diligent wine-grower,* and
1 Book xv. i. 1 6. 2 i. iii. 7, 8. 3 i. iii. 6, 7, 17.
4 Seneca evidently used his eyes to some purpose in the country.
He calls attention to the remarkable power of vegetation in displacing
Seneca on Underground JVater 31
in this capacity he had noted that the heaviest rain
does not moisten the earth for more than ten feet
downward, most of it flowing off into the beds of
streams. He gives his opinion, therefore, that rain
may make a torrent or help to swell a stream, but
that it cannot of itself be the source of a river flowing
with an equable course between its banks. If he is
asked whence, then, does the water of rivers come,
he replies that the question is as inept as it would
be to demand where air and earth come from. Water
being one of the four elements forms a fourth part
of nature. Why then should we be surprised if it can
always keep pouring out ? He knows that just as
in the human body there are veins which when
ruptured send forth blood, so in the earth there are
veins of water which are found even in the driest places,
at depths of two or three hundred feet below the
surface, and which when laid open issue in springs
and rivers. The water at these depths, so far below
the limits to which rain can moisten the earth, is not
regarded by him as of atmospheric origin, but living
water (aqua viva), for as all things are contained in
all, the earth, water and air can pass into each other.
The earth contains water which it presses out and
also air which, by the cold of winter, it condenses
into moisture ; the earth itself is also resolvable into
moisture.
Coming to the consideration of water at the surface,
he is on sounder ground when he discusses the
regime of rivers. He can see no more reason why
stones and destroying monuments, even the most minute and slender
rootlets being able to split open large rocks and crags, n. vi. 5.
32 Seneca on Rivers
we should wonder at the changes of volume in rivers
than we do at the regular succession of the seasons.
After an excellent account of a flood on the Danube,
of which we may believe him to have been an eye-
witness, he enters upon a discussion of the rise of
the Nile which he describes as it appears at Philae.
In rejecting the popular opinion expressed by the
tragedians that the cause of this annual phenomenon
is to be sought in the melting of snow on the
mountains of Ethiopia, he repeats the arguments of
Herodotus (whom however he does not cite) but with
the interesting addition, which he may have derived
from the explorers sent by Nero to the south of
Egypt, that in Ethiopia no hibernating animal had
ever been found, and that the serpent may be seen
there in winter even on the open high grounds. 1
The effects of floods in destroying woods, houses
and flocks are described, and the philosopher, in his
characteristic way, turns from a contemplation of these
events to moralise over the destiny of mankind. He
asks in what manner, when the fatal day of the
deluge shall arrive, will a large part of the earth's
surface be destroyed by water, whether the great ocean
will overwhelm us, or ceaseless torrents of rain, or
prolonged winter, pouring deluges from the clouds,
or rivers swollen into floods, and torrents rushing from
newly opened sources, or whether it will be by no
single agency, but when all will conjoin together ; when
rains will descend, rivers will overflow, the sea will
issue from its depths and all will sweep in one fell
array against the human race. 2
1 Book iv. ii. 7-30. 2 in. xxvii.
Geological Observations by the Greeks 33
3. Proofs of geological changes in the past. Through-
out the Mediterranean basin the profusion of well-
preserved marine shells in the upraised younger
formations which underlie the lowlands and crop out
along the sides of the hills, must have attracted the
notice of the earliest inhabitants. Accordingly we find
in Greek literature frequent allusion to them and to
the inference deduced from them that many tracts
of land had once lain beneath the sea. Xenophanes
of Colophon (B.C. 614) is recorded to have written
concerning sea-shells found among the inland hills
in Malta and elsewhere, and to have concluded from
them that they prove periodical submergences of the
dry land, wherein man and his dwelling-places have
been involved. Xanthus the Lydian (B.C. 464) is
quoted by Strabo as having seen shells like cockles and
scallops, far from the sea, in Armenia and Lower
Phrygia, and having inferred, from this evidence and
that of scattered salt-lakes, that these regions had
once been submerged beneath the sea. 1 Herodotus
noticed petrified sea-shells in the hills of Egypt,
especially those near the oasis of Jupiter Ammon,
and he too concluded from them, and from the saline
crust on the ground, that the sea had once spread over
Lower Egypt. 2 Some centuries later these observa-
tions were confirmed by Eratosthenes (B.C. 276-196)
who noted vast quantities of marine shells 2000 or
3000 stadia from the sea and for a distance of 3000
stadia along the road to the Ammon oasis, together
with beds of salt and saline springs. 3 Strato (B.C. 288)
also is quoted by Strabo as having come to the
1 Strabo, i. iii. 4. 2 n. 12. 3 Quoted by Strabo, loc. cit.
C
34 Aristotle on Geological Revohitions
conclusion that the temple of Jupiter Ammon was
once near the sea, which then spread over Egypt as
far as the marshes, near Pelusium, Mount Casius and
the Lake Sirbonis. He speaks of salt being dug in his
time in Egypt under layers of sand mingled with shells,
as if the whole region had formerly been covered by
a shallow sea that stretched across to the Arabian
Gulf. 1
No writer of antiquity has expressed himself more
philosophically than Aristotle regarding the past vicissi-
tudes of the earth's surface. Having studied so
carefully the operations of the various agents that are
now modifying that surface, he recognised how greatly
the aspect of the land must have been transformed
in the course of ages. His remarks on this subject
have a strikingly modern tone. He contemplates the
alternations of land and sea and furnishes- illustrations
of them, much as a geologist of to-day may do.
" The sea," he says, " now covers tracts that were
formerly dry land, and land will one day reappear
where we now find sea. We must look on these
mutations as following each other in a certain order,
and with a certain periodicity, seeing that the interior
of the globe, like the bodies of animals and plants,
has its periods of vigour and decline, with this dif-
1 Loc. fit. Strabo narrates his own experience as to fossils in the
rocks of Egypt. When standing in front of the Pyramids he noticed
that the blocks of stone that had been brought from the quarries
contained pieces which in shape and size resembled lentils (nummu-
lites) and he was told that these were remnants of the food of the
workmen turned into stone an explanation which he rejects as
improbable, though he cannot suggest a likely origin for them. xvn.
i- 34-
Aristotle on Geological Revohttions 35
ference, however, that while the whole of an organ-
ism flourishes and then dies, the earth is affected only
locally.
" These phenomena escape our notice because they
take place successively during periods of time, which,
in comparison of our brief existence, are immensely
protracted. Whole nations may disappear without
any recollection being preserved of the great terrestrial
changes which they have witnessed from beginning
to end. So too the increase in the area of habitable
land is brought about so imperceptibly in the course
of long ages that we can neither tell who were the
first inhabitants to settle in such new tracts, nor in
what condition they found the land." After quoting
in illustration the early history of Egypt and of the
territories of the Argives and Mycenians in Greece,
he remarks that what had transpired in a little district
appears to take place in precisely the same way in
more extensive regions and over entire countries. He
then proceeds to consider how these vicissitudes of
topography are to be accounted for.
" The cause to which such terrestrial mutations are
to be assigned may perhaps be that just as winter
regularly recurs among the seasons of the year, so a
great winter, lasting through a vast period of time, may
arise, bringing with it an excessive rainfall. Such a pre-
cipitation would not always affect the same countries.
Decalion's deluge, for example, only extended over
old Hellas which lies near to Dodona and the river
Achelous, which has often shifted its course. Land
that is lofty and has a cold temperature gives rise to
and retains an abundance of water which keeps it
36 Strabo's Geological Speculations
perpetually moist, while lower grounds, especially
where the rocks are porous, are the first to be dried
up. In course of time one area becomes more or
less desiccated, until a fresh return of a great period
of inundation." *
As geographical proof of the probability of these
suggestions, he refers again to the early condition of
Egypt. Herodotus had long before announced his
belief that the Nile had filled up with its sediments
the tract between Thebes and Memphis, once an
inlet of the sea, and had continued to push out its
silt so as to form the delta. Aristotle, enlarging on
the statements of the historian, declares that Egypt
was evidently at one time covered by a continuous
sea, and that the Nile, with its annual burden of
sediment, has shallowed this expanse of water, turning
it first into marshes which by degrees became entirely
dried up. He concludes with these remarkable words :
" It is clear that, as time never stops and the universe
is eternal, the Tanais and the Nile, like all other
rivers, have not always flowed ; the ground which
they now water was once dry. But if rivers are born
and perish, and if the same parts of the land are
not always covered with water, the sea must undergo
similar changes, abandoning some places and returning
to others, so that the same regions do not remain
always sea or always land, but all change their con-
dition in the course of time." 2
Though Strabo was more intent on recording geo-
graphical facts than indulging in geological speculations,
he could not refrain from sometimes intercalating a
1 Meteor, i. xiv. i et seq. 20. 2 Op. clt. i. xiv. 3 1 .
Ovid's Pythagorean Philosophy 37
pregnant remark as to the connection of the present
with the past. In regard to the interchange of land
and sea in former periods he held firmly to the doc-
trine so clearly expounded by the earlier philosophers.
" Every one will admit," he writes, " that at various
periods a great portion of the mainland has been
covered and again left bare by the sea." "All things
are continually in motion and undergo great changes,
much of the land being turned into water, and much
of the water changed into land. Some parts of the
earth now inhabited by man once lay beneath the sea,
while some portions of the bed of the sea were once
inhabited land." 1
The poet Ovid (B.C. 43-A.D. 18), who flourished
about the same time as Strabo, in a well-known passage
in the I5th book of his Metamorphoses represents
Pythagoras as himself expounding his view of the
system of Nature. This philosopher's doctrines have
only come down to us reported and perhaps distorted
by others. As Ovid introduces into Pythagoras' dis-
course allusions to some incidents which took place
long after the philosopher's death, the narrative cannot
be regarded as historically accurate, or as more than a
digest of what, in the time of Augustus, was believed
to be the Pythagorean philosophy. The sage is repre-
sented as maintaining that the world is eternal and
consists of the four elements air and fire above,
water and earth below. " Nothing in this world
perishes but only varies its form ; to be born is
merely to begin to be something different from what
we were before, and to die is to cease to be that same
1 Book xvn. i. 36.
38 Ovid on Geological Revolutions
thing. In spite of all transformation, the sum of
everything remains constant." The vicissitudes of
the earth's surface are then enumerated, and historical
examples of some of them are given. They may be
summarised in the subjoined paragraphs.
What was once solid land is now covered by the
sea, and new lands have been made out of the deep.
Sea shells have been found far inland, and the anchor
on a mountain crest.
Former plains have been carved into valleys by the
descending waters, and thus mountains have been
washed down into the sea.
Ancient lakes have been turned into tracts of burn-
ing sand, and dry ground has been changed to stagnant
marshes.
Nature has opened new springs in some places, and
elsewhere has closed up the old ones.
By former earthquakes many rivers have been made
to spring forth, or to sink down and disappear.
Places that were once islands, like Antissa,
Pharos and Tyre are now joined to the mainland,
and, on the other hand, tracts of once continuous
land are separated by sea-straits like the island of
Leucadia.
Cities have been submerged beneath the sea, as in
the case of Helice and Buris of which the walls, still
standing inclined beneath the waves, are pointed out
by the sailors.
Plains may be turned into hills, as happened at
Troezene where the violence of the winds, im-
prisoned in their dark caverns within the earth and
unable to find egress, heaved up the ground like
Ovid on Volcanoes 39
a bladder and made a prominent hill which still
endures. 1
Waters vary in temperature, some being cold during
the day and warm at morning and evening. Others
(accompanied with petroleum or inflammable gas) can
set wood on fire. Some have a petrifying quality, and
others have varying effects on the human body and
mind.
Islands once floating have become fixed, like the
ancient Ortygia which is now Delos, and the Sym-
plegades, which once terrified the Argo, but are now
anchored, and firmly defy the tempests.
Etna which now glows with its sulphurous furnaces
will not always be a burning mountain, and there was
a time before it began to burn. Whether the earth
is an animal that lives and breathes [forth flames from
many vents ; or winds pent up within the earth break
out and cast up stones and flame until the caverns
are emptied and cooled ; or some bituminous mass
has taken fire and burns until it dies away in faint
fumes of yellow brimstone ; a day will come when
the fires within will die out for lack of fuel.
From this sketch of the knowledge possessed by
the ancients regarding geological processes it appears
that while some sound observations had been made
and a certain amount of correct information had been
gathered together, speculation as to the causes of
things was much more cultivated than the patient
collection and comparison of facts. The same fanciful
J An account of this eruption is given by Strabo (i, iii. 18) and
its effects have been described by the late Professor Fouque of Paris,
Compt. rend. Ixii. pp. 904, 1121, and by other later writers
,
40 Character of Geology of the Ancients
hypothesis was accepted and reiterated for centuries,
without apparently any effort being made to test or
verify it by actual observation of nature. Certain
vague and more or less obvious inferences were drawn
as to ancient changes in land and sea, and some of
these changes were correctly referred to the agencies
that produced them. Yet the epigene forces of nature
were but partially comprehended, while the hypogene
activities were entirely misunderstood. Not even the
faintest suspicion had yet dawned on the minds of
men as to the long succession of events in the great
terrestrial evolution which geology has revealed. In
short nothing in this department of knowledge had
yet been accumulated to which the name of science
could be applied.
In one important respect, however, a momentous
forward step had been taken in the intellectual pro-
gress of mankind. The primeval belief that Nature
was governed by impulsive and capricious divinities,
interfering continually with the sequence of events,
had for centuries disappeared from the creed of all
reflective men, though it still found rhetorical ex-
pression among the poets. In its place had come
a more or less definite recognition that the world is
regulated by laws which, invariable and impartial in
their operation now, had been at work from the
beginning. The spread of this more enlightened con-
ception was happily untrammelled by any active
opposition either from a jealous priesthood or from
popular animosity. Each philosopher was at liberty
to hold and to express the views which he chose to
adopt, and while the old religion of classic paganism
Freedom of the Ancients 41
slowly lost its hold on the people, the rise of Chris-
tianity at first offered no impediment to the freedom
of philosophical inquiry. The fate of the Roman
Empire and the inroads of the barbarians arrested for
centuries the progress of natural history investigation.
When this progress was resumed towards the end of
the Middle Ages, a new spirit of intolerance had
arisen from which Antiquity had been free.
CHAPTER II
GROWTH of geological ideas in the Middle Ages Avicenna and the
Arabs : Baneful influence of theological dogma. Controversy
regarding the nature of fossil organic remains. Early observers
in Italy Leonardo da Vinci, Falloppio, Steno, Moro. The
English cosmogonists Burnet, Whiston, Woodward. Robert
Hooke, John Ray, Martin Lister, Robert Plot, Edward
Lhuyd.
DURING the centuries that succeeded the fall of the
Western Empire such learning as survived in Europe
was to be found only in the monasteries and other
ecclesiastical establishments. But it concerned itself
little with natural knowledge, save in as far as this was
contained in the works of the writers of antiquity.
From about the middle of the eighth century onwards
for some five hundred years, the Arabs kept alive
the feeble flame of interest in researches into the secrets
of Nature. With great labour and at large cost, they
procured as much as they could obtain of the literature
of Ancient Greece and Rome, and studied and translated
[into their own language the works of the best
writers in philosophy, medicine, mathematics and
astronomy. They were thus able to some extent to
enlarge the domain of these subjects. One of the most
Contents xi
CHAPTER XIII
Progress of Stratigraphical Geology The Transition or Greywacke
formation resolved by Sedgwick and Murchison into the Cam-
brian, Silurian and Devonian systems. The Primordial Fauna
of Barrande. The pre-Cambrian rocks first begun to be set in
order by Logan, - - pp. 406-437
CHAPTER XIV
Progress of Stratigraphical Geology continued Influence of Charles
Darwin. Adoption of Zonal Stratigraphy of fossiliferous rocks.
Rise of Glacial Geology, Louis Agassiz. Development of Geo-
logical map-making in Europe and North America, pp. 438-461
CHAPTER XV
The Rise of Petrographical Geology William Nicol, Henry Clifton
Sorby. Conclusion, - pp. 462-473
INDEX,- - - - p. 474
Amcennas Views in Geology 43
illustrious of the Arab authors was the famous Avicenna
(Ibn-Sina, 980-1037), the translator of Aristotle, whose
views he largely adopted. But if the volume " On
the conglutination of Stones " be truly ascribed to him,
he expressed, more clearly than his Greek master,
opinions regarding the origin of mountains and valleys
which show a singular forecast of modern geology.
" Mountains," he says, " may arise from two causes,
either from uplifting of the ground, such as takes
place in earthquakes, or from the effects of running
water and wind in hollowing out valleys in soft rocks
and leaving the hard rocks prominent, which has been
the effective process in the case of most hills. Such
changes must have taken long periods of time, and
possibly the mountains are now diminishing in size.
What proves that water has been the main agent in
bringing about these transformations of the surface, is
the occurrence in many rocks of impressions of aquatic
and other animals. The yellow earth that clothes the
surface of the mountains is not of the same origin as
the framework of the ground underneath it, but arises
from the decay of the organic remains, mingled with
earthy materials transported by water. Perhaps these
materials were originally in the sea which once over-
spread all the land."
With the revival of learning in Europe, attention
was once more drawn to the problems presented by the
rocks that form the dry land. More particularly did
the occurrence of fossil shells, far distant from the
sea, arouse inquiry. We have seen that in the days of
ancient Greece and Rome the questions suggested by
these objects did not wholly escape attention, and that
44 Theories of the Middle Ages
while, in general, no doubt was cast upon their organic
origin, the natural conclusion was drawn from them
that they proved the sea to have once overspread the
land.
This deduction was likewise adopted after the revival
of learning. But by this time the Church had gained
such an ascendency over the minds of men that no
opinions were allowed to be promulgated which
appeared to run counter to orthodox beliefs. If
therefore an observer who found abundant sea-shells
imbedded in the rocks forming the heart of a mountain
chain ventured to promulgate his conclusion that these
fossils prove the mountains to consist of materials
that were accumulated under the sea, after living
creatures appeared upon the earth, he ran imminent
risk of prosecution for heresy, inasmuch as according
to Holy Writ, land and sea were separated on the
third day of creation, but animal life did not begin
until the fifth day. Again, the overwhelming force
of the evidence from organic remains that the
fossiliferous rocks must have taken a long period
of time for their accumulation could not fail to
impress the minds of those who studied the sub-
ject. But to teach that the world must be many
thousands of years old was plainly to contradict the
received interpretation of Scripture that not more
than some 6000 years had elapsed since the time of
the Creation.
To court martyrdom on behalf of such speculative
opinions was not a course likely to be followed by
many enthusiasts. Various shifts were accordingly
adopted, doubtless in most cases honestly enough, in
The Controversy about Fossils 45
order to harmonise the facts of Nature with what
was supposed to be the divine truth revealed in the
Bible. A favourite mode of escape from the difficulty
consisted in denying that the fossils ever formed part
of living creatures. The old notion, first suggested by
Theophrastus, was revived, to the effect that there
exists within the earth a plastic force by which imitative
forms are produced, resembling those of true organisms,
but in reality as inorganic in origin as the plant-like
forms made by frost on window-panes. The fossils
were regarded as simply mineral concretions, and were
described as lusus naturae, mere freaks of Nature,
lapides sui generis, lapides figurati, " figured " or
" formed" stones. 1 Some writers, unable to detect
the action of any such formative agency in the earth
itself, supposed that the occult influence came from
the stars.
There were many observers, however, who could
not gainsay the evidence of their own senses, and
who recognised that either we must believe that
the minute and perfectly-preserved organic structures
in the fossils could only have belonged to once
living plants and animals, like those which possess
similar structures at the present day, or that the
Creator had filled the rocks of the earth's crust with
1 The earliest account of these objects accompanied with illustrative
plates was that of the distinguished Conrad Gesner (1516-1565)
De rerum fossi/tum, lapldum et gemmarum fguris, 1565. He had no
very clear idea as to the origin of these objects, some of which he
thought might be remains of plants or animals, while others he
regarded as more probably produced by some inorganic process,
as minerals and ores are formed.
4.6 Part attributed to Noah's Flood
these exquisitely designed but deceptive pieces of
mineral matter, with no apparent object unless to
puzzle and disconcert the mind of frail humanity. 1
If they refused to accept the latter alternative, they
found themselves face to face with the dogmas of the
Church and the consequences of professing disbelief
in them. The only escape from the dilemma which
then presented itself to such orthodox minds was to
have recourse to the Deluge of Noah. This event was
at that period regarded as having been a world-wide
catastrophe when, according to the sacred narrative,
" the fountains of the great deep were broken up, and
the windows of heaven were opened." For those
writers especially who had little or no personal acquain-
tance with the actual conditions of the problem, who
did not realise the orderly manner in which the fossils
are disposed, layer upon layer, for thicknesses of
many thousand feet in the solid rocks of the land,
the doctrine of the efficiency of the Flood offered a
welcome solution of the difficulty. They had no con-
ception of the physical impossibility of accumulating all
1 It is almost incredible how long some of these ignorant beliefs
lasted, and what an amount of argument and patience had to be
expended in killing them. I have been told that even within the
last century a learned divine of the University of Oxford used to
maintain his opinion that the fossils in the rocks had been purposely
placed there by the devil, in order to deceive, mislead and perplex
mankind. On the other hand, an opinion of a contrary tendency
was promulgated in the latter half of the previous century by a
Swiss naturalist, Bertrand, who suggested that the fossil plants and
animals had been placed there directly by the Creator, with the
design of displaying thereby the harmony of His work, and the
agreement of the productions of the sea with those of the land.
The Dilumalists 47
the fossiliferous formations of the earth's crust within
the space of one hundred and fifty days during which
a the waters prevailed upon the earth, and all the high
hills that were under the whole heaven were covered."
It was enough for them to obtain warrant from Scrip-
ture that, since the creation of animal life, the dry
land had been submerged, and to adduce evidence
from the rocks which they could claim as striking
corroboration of the truth of the biblical story. Hence
the " diluvialists," or those who claimed the Deluge
as a leading geological event in the history of the
earth, formed for many years a powerful body of
controversialists, who owed their influence and popu-
larity more to the impression that they were the
champions of orthodoxy than to the convincing nature
of their reasoning.
There could not, however, fail to be some observers
who, after making themselves acquainted with the
fossiliferous strata, found it impossible to believe that
such piles of rock, crowded with a succession of organic
remains, could have been the work of a transient
inundation such as Noah's Flood confessedly was.
Some of these men, struck with the rapidity with
which detrital materials can be accumulated on the
surface of the earth by volcanic outbursts, imagined
that the stratified rocks might have been formed by
the operation of active volcanoes. The volcanic
eruptions of Italy and the Aegean Sea had greatly
impressed the minds of Italian writers, who felt that
if, as in the case of Monte Nuovo on the shore of
the bay of Naples in year 1538, a hill, nearly 500
feet high, could be piled up in two days around a
48 Supposed Co-operation of Volcanoes
volcanic vent, it was at least conceivable that the
whole of the fossiliferous formations might have
been deposited by the same agency during the last
6000 years. So vague and inaccurate was the know-
ledge of rocks at that time, that those who started
this notion seem to have had no suspicion of how
entirely different in character and origin the ordinary
fossiliferous formations of the earth's crust are from
volcanic productions. Several generations had still to
pass, and detailed observations on stratified rocks had
to be laboriously made in many countries, before the
truth could be finally established that the fossiliferous
formations, many thousand feet in thickness, contain
a long record of geographical changes on the face
of the globe, and of a marvellous succession of organic
types which required a vast series of ages for their
evolution.
During the sixteenth, seventeenth and a great part
of the eighteenth century, the controversy over organic
remains and the part played by the Flood, while
keeping alive an interest in the subject, undoubtedly
hindered the advance of rational conceptions of the
fundamental facts of geological history. It was sin-
gularly unfortunate for the progress of this branch
of science that it should have aroused such ecclesias-
tical antagonism. For the true modern spirit of
observation and experiment had long been abroad and
at work in other branches of scientific inquiry wherein
the Church saw no danger, and where churchmen were
often among the foremost leaders. The necessity for
a close scrutiny of Nature, as the basis of sound deduc-
tion, had for generations been recognised by some of
Advice of Severinus 49
the more thoughtful minds before it was developed
into a system by Bacon. Even as far back as the
latter half of the sixteenth century, the method of
practical research, as opposed to mere book-knowledge
and theory, had been advocated even for the investi-
gation of the rocky part of the earth. It was pro-
claimed, in no uncertain voice, by the learned and
versatile Dane, Peter Severinus, who counselled his
readers thus : " Go, my sons, sell your lands, your
houses, your garments and your jewelry; burn up
your books. On the other hand, buy yourselves
stout shoes, get away to the mountains, search the
valleys, the deserts, the shores of the sea, and the
deepest recesses of the earth ; mark well the distinc-
tions between animals, the differences among plants,
the various kinds of minerals, the properties and
mode of origin of everything that exists. Be not
ashamed to learn by heart the astronomy and terres-
trial philosophy of the peasantry. Lastly, purchase
coals, build furnaces, watch and experiment without
wearying. In this way, and no other, will you
arrive at a knowledge of things and of their pro-
perties." l The modern spirit of investigation in
natural science could not be more clearly or cogently
enforced than it was by this professor of literature
and poetry, of meteorology and of medicine, in the
year I57I. 2
1 Petrus Severinus, Idea Medecinae Philosophicae, 1571, p. 73, cap.
vii. De principiis corporum (cited by D'Aubuisson).
2 It is curious to find a parallel passage to this extract written
a hundred years later by Robert Hooke. He declared that, in
spite of all the knowledge that had been acquired respecting the
50 Leonardo da Vinci
A brief survey of the progress of inquiry in Italy
will supply the best illustration of the slow advance
which was made in the demolition of long estab-
lished prejudice, and in paving the way for the ulti-
mate establishment of a philosophical conception of
the past history of the earth. One of the earliest
observers whose opinions have been recorded was the
illustrious painter, architect, sculptor, and engineer
Leonardo da Vinci (1452-1519). His attention hav-
ing been aroused by the abundantly fossiliferous nature
of some of the rocks in northern Italy, in which
canals were cut, he concluded that the shells con-
tained in these rocks had once been living on the
sea-floor, and had been buried in the silt washed off
the neighbouring land. He ridiculed the notion that
they could have been produced by the influence of
the stars, and he asked where such an influence
could be shown to be at work now. But he pointed
out that besides the shells, there were at various
heights, terraces of gravel composed of materials that
world we inhabit, an adequate natural history of the earth could
hardly be prepared until "after some ages past in making collections
of materials for so great a building, and the employing a vast number
of hands in making this preparation." He instanced the various
kinds of observers required and the methods and instruments to be
employed by them, " as by fire, by frost, by menstruums, by mixtures,
by digestions, putrefactions, fermentations, and petrifactions, by
grindings, brusings, weighings and measuring, pressing and con-
densing, dilating and expanding, dissecting, separating and dividing,
sifting and streining ; by viewing with glasses and microscopes,
smelling, tasting, feeling, and various other ways of torturing and
wracking of natural bodies, to find out the truth or the real effect,
as it is in its constitution and state of being." " Discourse of
Earthquakes," Posthumous Works, p. 279.
Fracastoro 5 1
had evidently been rounded and accumulated by
moving water.
The discussion received a fresh impetus from the
abundance and variety of the organic remains in the
blocks of stone brought for the repair of the Citadel
of San Felice at Verona, in the year 1517. In the
midst of the keen discussion that arose over these
fossils, the learned men of the country were con-
sulted, including Fracastoro (1483-1553) who after
being Professor of Philosophy at Padua had returned
to his native city, Verona, to practice there as a
physician. When various theories had been pro-
pounded, he announced his own opinion that the
shells could never have been left by the Mosaic
deluge, which he maintained had only been a tem-
porary inundation, caused by heavy rains, and would
have scattered the shells over the surface of the
ground, instead of burying them deep within the
strata that form the mountains whence the stones
had been quarried. He showed the absurdity of
attributing such organised forms to any imaginary
plastic force, and insisted that the fossils were
undoubtedly at one time animals that lived and
multiplied where their remains are now found, and
therefore that the mountains have been successively
uplifted above the sea. 1
Cardano (1552) pointed to fossil shells as certain
1 G. Brocchi, Conchologia Fossile Subapennina, Vol. i., " Discorso sui
Progress! dello studio della Conchologia Fossile in Italia," p. v. This
essay contains a valuable summary of the progress of the science of
fossil shells in Italy from the year 1300 down to 1810. The work
in two quarto volumes was published in 1814.
52 Cardano, Mattioli, Falloppio, Mercati
evidence that the sea once covered the sites of the
hills. His contemporary, Mattioli, on the other
hand, supported the old figment of the materia
pinguis, though admitting that porous bodies, such
as the bones and shells so abundant in Italy, might
be turned into stone by being permeated by a petrify-
ing juice. He is said to have been the first writer
who published a reference to the fossil fishes of Monte
Bolca. The skilful anatomist Falloppio (1557), when
he met with bones of elephants, teeth of sharks, shells
and other fossils, refused to admit them to be any-
thing but earthy concretions, because he deemed that
to be a simpler solution of the problem than to
suppose that the waters of the Deluge could have
reached as far as Italy. Aristotle had decided against
any universal flood, and the authority of this philo-
sopher was then about as potent as that of Holy
Writ. So much did Falloppio lie under the influ-
ence of this prejudice, that he thought it not unlikely
that the potsherds of Monte Testaceo at Rome
were in like manner natural productions of the
earth.
An important mineral collection, containing many
fossil shells, which had been gathered together in
the Vatican by Pope Sixtus V., was described and
excellently figured by Mercati (1574) who, however,
with all these well preserved organisms under his
eyes, denied their true organic nature, and came to
the conclusion that they were mere stones that had
assumed their present shapes under the influence of
the celestial bodies. It is worthy of notice that
another collection of natural history objects which,
Olivi, Cesalpino, Steno 53
in the latter half of the same century had been
formed at Verona, was described by Olivi (1584) who
regarded the fossil organisms as mere sports of Nature.
Cesalpino (1566) who had distinguished himself as
a botanist, turned in his later years to mineral studies,
and wrote a volume De Metallicis, which may still
be usefully consulted for information on the stones
and ores of Italy. He recalled attention to the true
doctrine regarding fossil shells, which he looked
upon as organisms that had been left by the retir-
ing sea, and had been turned into stone by the
petrifying influence of the surrounding rock. Majoli
suggested that fossil shells on the land had been
ejected from the sea-floor by submarine volcanic ex-
plosions.
In the crowd of Italian writers who took part in this
long controversy, by far the most illustrious was Nicolas
Steno (1631-1687). Born in Copenhagen, he studied
medicine and took his degree there, afterwards passing
to Leyden and then to Paris, where he remained two
years, attaining great distinction by his discoveries in
human anatomy. He next travelled through Austria
and Hungary, and eventually settled in Florence where,
at the age of thirty-six, he was appointed physician
to the Grand Duke Ferdinand II. Not long there-
after, reflecting on the arguments which had been
put before him by Bossuet in Paris, he abjured the
Lutheran protestantism in which he had grown up, and
became a member of the church of Rome. His
European reputation led to repeated invitations being
sent to him from King Christian V. of Denmark to
accept the Chair of Anatomy in Copenhagen. To
54 S tends Career
these solicitations he at last yielded, but although he
had full authority to exercise the rites of Roman
Catholicism, he now encountered so many unpleasant-
nesses in the Protestant community of his native city
that he finally quitted his fatherland, and returned to
Florence, where he was entrusted with the education
of the son of the Grand Duke Cosmo III. Gradually
becoming entirely devoted to a religious life, he took
orders and in 1677 was named Bishop of Heliopolis
and Vicar Apostolic in the north of Europe. He
thereafter employed his leisure in composing a series of
theological works. But it is upon the value of his
anatomical and geological writings that his fame mainly
rests. In 1667, soon after first settling in Florence, he
published the anatomy of the head of a dog-fish and
discussed the question whether the u glossopetrae,"
or sharks' teeth, found in the rocks, belonged to such
fishes, or were mere mineral concretions, produced by
some process within the stone in which they lie.
Though he inclined to believe them to be truly of
organic origin, his statements were made with so much
timid reservation as to show how cautious even the
acutest intellects were constrained to be in touching
on any subject likely to rouse the orthodox prejudices
of the age. Two years afterwards, however, having
meanwhile enlarged his acquaintance with the rocks
and fossils of Northern Italy, he proclaimed with
frank boldness his conviction that the fossils were
once living things, and that they and the strata con-
taining them revealed a record of part of the history
of the earth.
In 1669 there appeared in Florence his treatise
S tends Doctrines 55
De Solido intra soliaum naturaiiter contento^ which must
be regarded as one of the landmarks in the history
of geological investigation. It was meant to be intro-
ductory to a fuller work on the same subject, but
this expansion was never written. The following digest
of the contents of the treatise will show how far Steno
had advanced beyond any of his predecessors or con-
temporaries, and how modern and familiar some of
his original views now appear.
The strata of the earth are such as would be laid
down in the form of sediment from turbid water.
The objects enclosed in them, which in every respect
resemble plants and animals, were produced exactly
in the same way as living plants and animals are pro-
duced now. Where any bed encloses either fragments
of another, and therefore older, bed, or the remains
of plants or animals, it cannot be as old as the time of
the Creation. If any marine production is found in
any of these strata, it proves that at one time the sea
has been present there ; while, if the enclosed remains
are those terrestrial plants or animals, we may suspect
the sediment to have been laid down on land by some
river or torrent.
Similarity of composition in a series of strata proves
that the fluid from which the sediment was deposited
continued to be unaffected by other fluids coming from
other directions at different times : on the other hand,
a diversity in the character of the strata points either to
a commingling of different kinds of fluids, bearing
divers sediments, and caused perhaps by violent winds
and rains, or to a diversity in the composition of the
sediment, of which the heavier materials would first
56 Stends Doctrines
sink to the bottom. The presence of coals, ashes,
pumice, bitumen or burnt substances shows the former
neighbourhood of some subterranean fire.
Steno established by direct observation some im-
portant axioms in stratigraphy. Every stratum, he
said, has been laid down upon a solid subjacent surface.
The lowermost strata must have become firm before
the uppermost were deposited. A stratum must
originally have terminated laterally against a solid body,
or else must have extended over the whole earth, so
that when the truncated ends or edges of strata are
exposed, we must either seek for evidence of their
former prolongation, or for the solid surface against
which they ended and which kept their materials from
slipping down. 1 As each bed at the time of its for-
mation was covered only with fluid, when the lowest
member of a series was laid down none of those
above it had yet been deposited.
The bottom of a series of strata necessarily conforms
to the irregularities of the surface on which it has been
deposited, but the upper surface, where the rocks are in
their original position, is parallel to the horizon or
nearly so. Hence all strata save the lowermost lie
between two plains approximately parallel with the
horizon. We must, therefore, conclude that strata
which are now vertical or inclined to the horizon were
originally nearly or quite horizontal.
That the edges or sides of the strata are laid bare
1 Steno had not realised the really lenticular character of all
sedimentary strata. But his conclusion that the truncated ends of
strata on a cliff-face point to the former continuation of the strata
beyond their present termination, is now a commonplace in geology.
Stends Doctrines 57
in so many places, is to be ascribed to the operation
of running water which dissolves and transports earthy
substances to lower levels, and also to the action of
fire in dissipating solid bodies, and ejecting them above
ground. Thus precipices and channels are produced
on the surface of the earth, and caverns and tunnels
underneath. The strata are sometimes disrupted by
the sudden rise of subterranean exhalations ; at other
times they are broken up by the falling in of the
roofs of cavernous spaces inside the earth. Hence
they are thrown into a great variety of different
positions, being sometimes vertical, more often in-
clined at various angles, occasionally even bent into
arches.
This alteration in the original position of strata is
the real cause of the inequalities of the earth's surface,
such as mountains and plains. Some mountains have
also been produced by the outburst of fires from inside
the earth, whereby ashes and stones, together with
sulphur and bituminous substances, have been cast
forth. It is easy to perceive that all our mountains
have not been in existence since the beginning of
things.
Steno then proceeds to show that by the disruption
of the strata, outlets have been provided for the
escape of materials from inside the earth. Chief among
these are the springs of water that issue from the
hills. The cracks, fissures and cavities of the strata
have served as receptacles for most minerals, whether
introduced by vapours or otherwise. The question
of the origin of rock-crystal gives the author occasion
to discourse on the crystallography of this mineral,
58 Steno on Fossils
and on the conditions in which crystalline substances
and ores have been produced within the earth.
Among the solids naturally enclosed within other
solids, Steno includes, as specially deserving of con-
sideration, fossil shells. His anatomical experience
enables him to declare with confidence that even if
no living marine shells had ever been seen, the
internal structure of the fossils demonstrates that they
once formed parts of living animals. He shows that
the fossils vary in character according to the extent
to which they have been petrified, some still retaining
their original composition and internal structures, others
having become entirely crystalline, as in those enclosed
in marble. He points out further that over and above
the predominant testaceous fossils, remains of many
other marine animals have been preserved in the strata,
such as teeth and vertebrae of dog-fishes, and all kinds
of fish-skeletons, while other strata have furnished the
skulls, horns, teeth and bones of land animals. 1 Against
those who found an insuperable difficulty in granting
the length of time required for all the vicissitudes
indicated by the strata and their fossils, Steno argues
that many of the organic remains found in the rocks
must be as old as the general Deluge, and he proceeds
to present a summary of what he conceives to have
1 It is curious to observe that Steno, while he recognised that teeth
and bones exhumed from the Agro Aretino were those of elephants,
did not realise that they too must be regarded as of prehistoric age.
He supposed them to be relics of the African elephants brought into
Italy by Hannibal. Brocchi has pointed out that after the battle of
the Trebbia the thirty-seven elephants which the Carthaginian general
had by the side of the Rhone were reduced to one single animal.
Op. cit. p. xv.
Stenos Geological History 59
been the geological history of Tuscany. In this sum-
mary he illustrates the structure of the country by a
series of diagrams which show how clearly he had
grasped some of the fundamental principles of strati-
graphy. He recognises evidence of six distinct chrono-
logical phases, and is inclined to believe that the same
sequence will be found all over the earth. In the first
phase, the region was entirely submerged under the
sea, from which were deposited the strata containing
no remains of plant or animal life. In the second
phase, the land appeared as a dry plain, raised out
of the sea. In the third, the face of the earth was
broken up into mountains, crags and hills. In the
fourth, the land was once more submerged, perhaps
owing to a change in the centre of the earth's gravity.
In the fifth, the land reappeared and displayed wide
plains, formed apparently from the sediments carried
off from the land by the large rivers and by the
innumerable torrents which every day are extending
the shores and leaving new lands to be occupied by
fresh inhabitants. In the sixth and last phase, the
elevated plains were eroded by running water and
partly also by the co-operation of subterranean fire, so
as to be altered into channels, valleys and precipices.
Steno's treatise stands out far above all the writings
of his own or of previous generations in respect to the
minuteness and accuracy of his observations of Nature
and the originality and truth of most of the deductions
which he drew from them. He was the first clearly to
perceive that the strata of the earth's crust contain the
records of a chronological sequence of events, and that
the history of the earth must be deciphered from them.
60 Vallisneri
He laid down for the first time some of the funda-
mental principles of stratigraphy. He recognised the
predominant influence of running water in carving out
the inequalities on the surface of the land. It is
true that he had no clearer notions than had obtained
for so many centuries regarding the true nature of
volcanic action, which he still regarded as due to the
subterranean combustion of carbonaceous substances.
He was hampered too by the prevailing theological
doctrine that the earth could not be more than some
6000 years old, and that the fossiliferous strata had
been mainly deposited during or since Noah's Deluge.
But his name must be enrolled high in the list of
those who by careful observation and deduction helped
to lay the foundations of modern geology.
Another illustrious observer in the geological domain
appeared in Italy when Steno, in his twenty-fifth year,
was rapidly rising into fame as an anatomist. Antonio
Vallisneri (1661-1730) became professor of medicine
in Padua. In the course of his journeys he had
opportunities of seeing much of the geology of his
native country and of forming a clearer conception
of the fossiliferous formations of the great central
mountain-chain than anyone had done before him.
He looked upon the shells in the rocks as remains
of mollusks that once undoubtedly lived in the sea.
In criticising the cosmological hypothesis of Wood-
ward (to be afterwards alluded to), he showed how the
Italian marine formations extend not only throughout
the peninsula but over a large part of Europe, and he
inferred that there was a time when the sea covered
the whole surface of the globe. He believed that it
Anton-Lazzaro Moro 61
must have remained in that position for a long period,
and that its effects were altogether distinct from those
of the temporary Deluge of Noah. He wrote on the
origin of springs, maintaining that they do not come
from the sea, through subterranean passages in which
they lose the saline constituents of sea-water a belief
that had survived from antiquity and was still de-
fended as resting on scriptural evidence. He connected
springs with the structure of the rocks through which
they rise. 1
To one other notable Italian writer, who appeared
in the first half of the eighteenth century, reference
may here be made. Anton-Lazzaro Moro (1687-1740)
wrote a treatise De Crostacei e degli altri marini Corpi
che si truovano su Monti (Venice, 1740). The
grotesque speculations of Burnet and Woodward,
which will be more particularly referred to on a later
page, had already appeared in England and had found
their way into the Continent. A large part of Moro's
work is devoted to a destructive criticism of the
cosmogonies of these authors. He then proceeds to
discuss the possibility of explaining the position of
fossil shells in the mountains by reference to the
Noachian Deluge, and he dismisses this supposition as
untenable. He next inquires in what manner the
phenomenon can be explained from actual observa-
tions of natural processes. After giving an account
of the uprise of a new volcanic island in the Greek
Archipelago in the year 1707, of the appearance of
Monte Nuovo near Naples in 1538, and of the
1 Vallisneri's treatise Dei Corpi marini eke sui montl si trovano was
published at Venice in 1721, when its author was sixty years of age.
6 2 Moro's Volcanic Theory
recorded eruptions of Vesuvius and Etna, and starting
with the proposition that the fossil shells are really
productions of the sea, he proceeds to unfold his
theory that the position of these shells, and the origin
of the rocks that enclose them, are to be assigned to
the operation of volcanic action.
In the beginning, he says, the globe was completely
covered with water, which was then fresh and perhaps
not more than 175 perches in depth. No prominences
diversified the smooth stony surface of the globe
which underlay the water. On the third day of
creation, however, when it pleased the Almighty to
reveal the solid earth, vast subterranean fires were
kindled, whereby the surface of stone was broken up,
and huge masses of it began to appear above the
water, so as to form the land and rnountains. These
disrupted masses, while rising or after they had risen,
and in some cases even before they appeared above
the water, were rent open by the violence of the
subterranean fires, and they discharged from their
orifices vast quantities of material, such as earth, sand,
clay, stones both solid and liquid, metals, sulphur,
salts, bitumen and every kind of mineral substance.
Part of this material flowed in river-like streams
down the sides of the mountains into the water
below, part fell in showers from the air into which
the ejected detritus had been hurled by the impetuosity
of the fire. The saline and bituminous ingredients
now began to give to the water the salt and bitter
taste which the sea has retained ever since, while the
other insoluble substances formed a new bottom above
the original stony surface.
Mords Geological History 63
As the mountains increased in number by the out-
burst of new vents and continued to cast forth loose
materials, they gradually piled up on the sea-floor
many various strata which, especially near the eruptive
centres, eventually rose above the surface of the water.
The sea grew deeper or its surface rose higher, the
more its area was diminished. Fires also afterwards
burst out from below the submarine strata, and con-
tinued to eject fresh materials which formed new
strata that extended beyond those of earlier date.
New islands were formed, or were added to older
islands or to the continents.
As yet no plants or animals existed. But while the
water continued to grow more saline, plants began at
last to appear both in the sea and on land. Animals
too entered upon the scene, first in the sea, living in
the soft sand and among the debris cast out by the
mountains, and seldom wandering far from their
native places. The dry land became covered with
verdure and gave birth to terrestrial animals, finally
followed by the advent of man, who then took his
place as an inhabitant of this first and most ancient
land-surface.
In course of time, the same sequence of events
continuing, new mountains emerged from the bosom
of the earth, and like their predecessors vomited forth
fresh materials which were once more spread out over
the floor of the sea and the surface of the land. The
strata that were thus deposited in the sea would con-
tain marine productions, while those formed on the
land would preserve terrestrial remains, including
articles in metal, marble or carved wood as relics of
64 Mords Orthodoxy
a human population. Some of these land-surfaces,
remaining long exposed to the open-air, were covered
with new strata, which when they differed in composi-
tion from those buried below them, would produce
plants and animals distinct from any of those which
had previously existed on the same sites. And since
the newer strata were not all laid down universally and
at the same time, but successively during the course
of centuries and at different seasons of the year, seeds
and fruits in mature and immature condition would
be entombed, as may be illustrated by many examples
that have actually been obtained from excavations in
which, at different levels, old soils represent inhabited
and cultivated surfaces of land.
Moro had to take care that his cosmogony did not
contradict but only supplemented the orthodox read-
ing of the first Chapter of the Book of Genesis. That
he succeeded in this aim is indicated by the imprimatur
at the end of his treatise, wherein the reformers of
studies testify that the book contains nothing contrary
to the Holy Catholic Faith, nor anything adverse to
Princes or to morals. Though he declined to adopt
the popular notion that the stratified rocks had been
formed during Noah's Flood, he still felt bound to
account for their deposition within the orthodox limits
of time. Public attention had been called to the
rapid accumulation of materials around active volcanic
vents, and Moro, availing himself of the original
suggestion of Majoli, boldly claimed that all the
stratified rocks which form the mountains consist of
materials successively erupted by volcanoes. He does
not seem to have ever studied the nature of true
Rise of the Cosmogonists 65
volcanic products, nor to have been familiar with the
characteristic features of the limestones and other cal-
careous strata in which so large a proportion of fossil
organic remains is preserved. He added little to the
more luminous conceptions of Steno and Vallisneri.
But his influence was not inconsiderable in rousing
interest in the themes of which he treated. Nine
years after his book appeared, the Carmelite friar
Generelli, published an exposition of Moro's views,
which he placed in a clearer light than his master
had done.
The progress of geological inquiry in Europe during
the seventeenth century was marked by a character-
istic feature the development of a series of cosmo-
gonical systems, in which the only common basis of
speculation was the effort to account for the origin
of our globe and of our universe, in harmony with
the teaching of the Church. Science had not advanced
far enough to afford any firm basis for speculations of
this nature, and consequently the lack of data was in
too many cases supplied by wholly imaginary pictures
of the history of creation. The systems of cosmo-
gony thus framed, though some of them attained
considerable fame in their day, obstructed the pro-
gress of inquiry, inasmuch as they diverted attention
from the observation of Nature into barren contro-
versy about speculations. In vain did those who
had mastered some of the elementary truths about
the crust of the earth, oppose and even ridicule
these fanciful systems. The cosmogonists were not
disconcerted when phenomena were appealed to that
contradicted their theories, for they usually never
66 The English Cosmogonists
saw such phenomena, and when they did, they easily
explained them away. Some of these writers were
divines, yet even when they were laymen they felt
themselves, down to the middle of the eighteenth
century, bound to suit their speculations to the re-
ceived interpretation of the books of Moses. Looking
back from our present vantage ground, it is difficult
to realise that even the little which had been ascer-
tained about the structure of the earth was not
sufficient to prevent some, at least, of the monstrous
doctrines of these theorists from being promulgated.
It was a long time before men came to understand
that any true theory of the earth must rest upon
evidence furnished by the globe itself, and that no
such theory could properly be framed until a large
body of evidence had been gathered together.
Nowhere did speculation run so completely riot as
in England with regard to theories of the origin and
structure of our globe. This craze reached its height
during the latter part of the seventeenth century. In
1 68 1 Thomas Burnet published in Latin his Sacred
Theory of the Earth. This work, republished in Eng-
lish, and favoured with the patronage of Charles II.,
enjoyed a wide popularity and made some impres-
sion even on the Continent. It discoursed of the
original structure of our planet, and of the changes
which it was destined to undergo until " the consum-
mation of all things." As its title denotes, the book
was meant to support orthodox religion. With this
view, the Deluge was taken as one of the great events
in the history of the planet. Previous to that time, it
was asserted, there had been perpetual spring upon the
Burnet, IVhiston, and Woodward 67
earth, but the wickedness of mankind led to a cata-
strophe in which the sun's rays split open the crust
of the earth, and allowed the central abyss of waters
to burst forth and overwhelm the inhabited lands.
William Whiston in his New Theory of the Earth
(1696) propounded almost more extravagant specula-
tions. He supposed that at the time of the Creation
the earth did not rotate on its axis, but that after the
Fall of Man it began to do so. When the years
had passed until the time of Noah, a comet on i8th
November B.C. 2349 sent its tail over the equator,
and caused a gigantic downpour of rain, while at the
same time the internal abyss of waters broke forth
and inundated the land. It was from the " chaotic
sediment of the flood " that the various stratified
formations of the earth's crust were deposited.
Another English writer who attributed similar
important effects to the Deluge was John Woodward,
familiarly remembered by the bequest of his collection
of specimens to the University of Cambridge, and by
the Professorship of Geology there which perpetuates
his name. He had an intimate acquaintance with the
stratified formations of a large part of England and with
their characteristic fossils. While firmly convinced that
these fossils were really the remains of once living
plants and animals, he could not free himself from
the incubus of the prevailing theological prejudice.
In his Essay towards a Natural History of the Earth
(1695) ne ran ged himself with those who maintained
that the shells in the rocks were relics of Noah's Flood.
He held a common belief of his day that the interior
of the earth was once full of water, which at the time
68 Robert Hooke
of that calamity, when the fountains of the great
deep were broken up, burst forth and swept over the
face of the globe. The disrupted and disintegrated
crust was mingled with the diluvial waters, from which
the sediments ultimately settled down on the bottom
in the order of their gravity. By a curious perversity
of judgment, Woodward persuaded himself that the
fossils had followed the same rule and that the heaviest
were found in the lowest strata, the lightest in the
uppermost a statement afterwards sharply criticised
by Ray.
Woodward's most important contribution to science
is his catalogue of the fossils which in the course of
long years he had collected in England, and which
now form an interesting portion of the Sedgwick
Museum at Cambridge. It is entitled " An attempt
towards a Natural History of the Fossils of England
etc., or a Catalogue of English Fossils" in the collection
of J. Woodward M.D. 2 vols 1728-29.
Of a totally different stamp from the cosmogonists
above mentioned was the mathematician and natural
philosopher Robert Hooke (1635-1703), one of the
most brilliant, ingenious, and versatile intellects of
the seventeenth century. Among the many subjects
to which he directed his attention and on which his
remarkable powers of acute observation and sagacious
reflection enabled him to cast light, some of the more
important problems of geology must be numbered.
As "Curator of Experiments" to the Royal Society,
and as one of the most active members of that body,
he had frequent opportunities of discoursing on the
topics which engaged his thoughts. From time to
Hooke s Discourses 69
time he lectured on what would now be called physical
geography and geology. Such lectures as remained
in manuscript after his death were collected and
published in a folio volume of posthumous works
(London, 1705). The largest section of this book
consists of c< Lectures and Discourses of Earthquakes
and Subterraneous Eruptions, explicating the Causes
of the Rugged and Uneven Face of the Earth ; and
what Reasons may be given for the frequent finding
of Shells and other Sea and Land Petrified Substances
scattered over the whole Terrestrial Superficies." 1
Beginning with an account of " figured stones "
or organic remains imbedded in rocks, illustrated with
well-drawn figures of fossils, Hooke discusses the
difficulties met with in explaining the nature and origin
of these objects, and proves in a series of propositions
that the fossils are either the organisms themselves
turned into stone, or the impressions left by them ; 2
that a great part of the surface of the earth has been
transformed since the Creation, sea being turned into
1 Though the volume did not appear until after the author's death,
the first discourse seems to have been given in 1 668.
2 The truly organic nature of the fossils is the subject of a
careful demonstration by Hooke, in the course of which he
remarks " that it is contrary to all the other acts of Nature, that
does nothing in vain, but always aims at an end, to make two
bodies exactly of the same substance and figure, and one of them
to be wholly useless, or at least without any design that we
can with any plausibility imagine." The fossils "if they were
not the shells of fishes, will be nothing but the sportings of
Nature, as some do finely fancy, or the effects of Nature idely
mocking herself, which seems contrary to her gravity." Posthumous
Works, p. 318.
70 Hookes Geological J^iews
land, land into sea, mountains into plains and plains
into mountains ; that most places where fossil plants
or animals have been found have lain under water,
" either by the departing of the water to another part
or side of the earth, by the alteration of the centre of
gravity of the whole bulk, which is not impossible ; 1
or rather by the eruption of some kind of subterraneous
fires, or earthquakes whereby great quantities of earth
have then been raised above the former level of those
parts " ; that not improbably the tops of the highest
mountains in the world have been under water, these
elevations of the land having most probably been
the effects of some very great earthquake ; that the
greatest part of the inequalities of the earth's surface
may have been caused by u the subversion and
tumbling thereof by some preceding earthquakes " ;
that " there have been many other species of creatures
in former ages, of which we can find none at present ;
and that 'tis not unlikely also but that there may be
1 The possible change of the earth's centre of gravity is fully
discussed by Hooke in several discourses. A passage in which the
idea is expressed gives a vivid picture of the philosopher's prescient
outlook in terrestrial physics. He conceives that a very great earth-
quake (using that word for any kind of displacement of the
terrestrial crust) might not impossibly alter the centre of gravity
and also the axis of rotation. He thinks that the diurnal rotation
and annual revolution of the globe may once have been made in
a much shorter time than now, so that a day and a year at the
beginning of the world would not have been so long as now
when these motions have become slower. He further suggests
that " the fluid medium in which the earth moves, may after a
thousand revolutions, a little retard and slaken that motion, and
if so, then a longer space of time will pass while it makes its
revolution now than it did at first." Op. dt. p. 322.
Hooke on Fossils 71
diverse new kinds now, which have not been from
the beginning."
With regard to the inequalities of the earth's surface,
Hooke enters fully into the effects of the earthquakes
by which he thinks they have been produced. Some
earthquakes raise the earth's surface, either by
upheaval or by piling up " a great access of new
earth " ; others depress the surface : those of a third
type disrupt and subvert parts of the earth ; while
by a fourth class liquefactions, vitrifications, calcina-
tions, sublimations and other effects are produced.
He shows how universal is this active principle of
terrestrial change, no country in the whole world
having escaped being shaken sometime or other by
earthquakes.
Having demonstrated from organic remains that
the dry land must have lain for some time under
water, Hooke argues that this water could not have
been the Flood of Noah, which did not continue
long enough " for the production and perfection of so
many and so great and full-grown shells ; besides, the
quantity and thickness of the beds of sand with which
they are many times found mixed, do argue that
there must needs be a much longer time of the sea's
residence above the same, than so short a space can
afford." 1 The large size of some of the shells as
well as their resemblance in form to some of those
found in tropical seas leads him to ask whether it is
impossible that the South of England, where these
shells are found, may for some ages past have lain
within the Torrid Zone. Thus fossil organic remains
72 Hooke on the Use of Fossils
were in Hooke's eyes not mere curiosities, but valuable
records of the past history of the earth. " I do
humbly conceive," he remarks, " (tho' some possibly
may think there is too much notice taken of such a
trivial thing as a rotten shell, yet) that men do
generally too much slight and pass over without
regard these records of antiquity which Nature have
left as monuments and hieroglyphick characters of pre-
ceding transactions in the like duration or transactions
of the body of the Earth, which are infinitely more
evident and certain tokens than anything of antiquity
that can be fetched out of coins or medals, or any
other way yet known, since the best of those ways
may be counterfeited or made by art and design, as
may also books, manuscripts and inscriptions, as all
the learned are now sufficiently satisfied, has often
been actually practised ; but those characters [fossil
shells] are not to be counterfeited by all the craft in
the world, nor can they be doubted to be, what they
appear, by any one that will impartially examine the
true appearances of them : And tho' it must be
granted that it is very difficult to read them and
to raise a chronology out of them, and to state the
intervalls of the times, wherein such or such cata-
strophies and mutations have happened ; yet 'tis not
impossible, but that much may be done even in that
part of information also." 1
Hooke does not appear to have formed any very
clear ideas either as to the causes of earthquakes or
the nature of volcanic action. He connects the two
classes of phenomena together, and in various places
J p. 411.
John Ray 73
alludes to them as effects of " the general congregation
of sulphureous, subterraneous vapours." He thinks
that the observed greater frequency of earthquakes
and volcanoes on islands and sea-coasts may possibly
be due to " the saline quality of the sea- water which
may conduce to the producing of the subterraneous
fermentation with the sulphureous minerals there
placed." " These fermentations subjacent to the sea,
being brought to a head of ripeness, may take fire,
and so have force enough to raise a sufficient quantity
of the earth above it to make its way through the
sea, and there make itself a vent." " The foment or
materials that serve to produce and effect conflagra-
tions, eruptions or earthquakes, I conceive to be
somewhat analogous to the materials of gunpouder." 1
This philosopher had therefore advanced no further,
in regard to the hypogene agents in geology, than the
writers of antiquity and of the middle ages.
How far the ideas imposed by the prevailing
theological beliefs of the period could influence even
a man of eminent scientific ability is perhaps most
fully illustrated in the case of John Ray (1627-1705),
the ablest botanist and zoologist of his day, to whom
science has been indebted for some masterly contribu-
tions to its progress. With his wide sympathies for
Nature, he could hardly avoid entering the geological
field, and as he was a loyal and devoted member of
the Church of England, he could scarcely escape from
carrying with him more or less of the ecclesiastical
prejudices of his time. Where these prejudices were
not involved he could see things as they are, and draw
!pp. 421, 424.
74 Ray's Geological Opinions
the natural inferences to which they lead. Thus he
entered fully and sagaciously into the theory of
springs, quoting his own experience at his country
home, and showing conclusively, in opposition to
Hooke, that it is not by dews condensed on the
mountains but by the water supplied by rain that
springs are fed. He watched, too, the effects of
running water, especially the manifest action of " rains
continually washing down and carrying away earth
from the mountains," and the destruction of the
shores by the perpetual working of the sea, and he
believed that in the end, by the combination of these
processes, the whole dry land might possibly be re-
duced below the sea-level. 1
When Ray came to discuss " formed stones," or
" sea-shells and other marine bodies found at great
distances from the shores," he was obviously no longer
free to do so untrammelled as to what conclusions
he might draw from them. He caustically criticises
Woodward's diluvial theory, remarking that he sus-
pected that author to have invented part of his theory
to solve supposed facts which are not generally true.
But though he had " spent many thoughts " on this
subject, he confesses that he could not fully satisfy
himself as to the nature and real origin of the
"formed stones." He balances the arguments for
and against their truly organic origin, seeming at one
moment to agree with those who regarded them as
1 Miscellaneous Discourses concerning the \Dissolution and Changes of the
World, by John Ray, Fellow of the Royal Society, London, 1692,
pp. 44-56, and Three Physico-Theological Discourses, 4th Edit., 1721,
pp. 89-114, 245.
Ray on Rarthquakes and Volcanoes 75
"originally formed in the places where they are now
found by a spermatic principle," and yet unable to
resist the evidence that " these bodies owe their
original to the sea, and were sometimes the shells or
bones of fishes."
As regards hypogene phenomena Ray made no
advance. Thus he says : " That the cause of earth-
quakes is the same with that of thunder, I doubt
not, and most learned men are agreed ; that is,
exhalations or steams set on fire, the one in the
clouds, the other in the caverns of the earth." *
Volcanoes are regarded by him as connected with
earthquakes and due to the heating of " steams or
damps " within subterranean caverns " by a collucta-
tion of parts," whereby combustible materials in the
hollows of the mountains are set on fire and the
metals and minerals are melted down, while if water
enters these caverns " it mightily increaseth the raging
of the mountain, for the fire by the help thereof
throws up earth and stones, and whatever it meets
with." 2 Yet Ray, while he "utterly disallowed and
rejected" Descartes' theory of the origin of the earth,
was not unwilling to admit the existence of a central
fire, more especially as it would presumably support
the references to Hell in the Bible. But he does not
appear to have ever thought of connecting this pos-
sible central fire with the operations of active volcanoes.
That Ray, in spite of his instinct as a naturalist
and keen observer, should have been shaken in his
opinion that the fossils in the rocks are the remains
of once living things, can hardly surprise us when we
1 Three Physico-Tkcological Discourses, p- 258. 2 p. 268.
j6 Martin Lister on Fossils
remember that the two men who in all England had
the most extensive acquaintance with fossils refused
to admit them to be of organic origin. Martin
Lister (1638-1712), an active and able fellow of the
Royal Society, published a remarkable history of all
the shells then known, with accurate plates, which
included not only the living species but many fossil
forms placed with them for comparison. Yet strange
to say, he stoutly refused to believe that the fossils
had ever belonged to living creatures. " For our
English inland quarries," he said, " I am apt to think
there is no such matter as petrifying of shells in
the business ; but that these cockle-like stones are
everywhere as they are at present, lapides sui generis,
and never were any part of an animal," that they
" have no parts of a different texture from the rock
or quarry whence they are taken, that is, that there
is no such thing as shell in these resemblances of
shells." He admitted that some of the fossils are
like Murices, or Tellinae or Turbines, etc., yet he had
never met with any one of them on any English
sea-shore or fresh- water ; whence he concluded a that
they were not cast in any animal-mold, whose species
or race is yet to be found in being at this day."
Having made up his mind with the evidence fully
before him, it was only natural that, as Woodward
tells us, " he bravely continued to the last firm and
unshaken in his opinions."
Lister made the ingenious suggestion that volcanic
eruptions may be due to the subterranean decomposi-
tion of iron-pyrites. Even among those who from
l Phil. Trans, vol. v. (1671), p. 2282.
Lister, Plot, Lhuyd 77
time immemorial had regarded volcanic action as
arising from the combustion of inflammable materials
in the crust of the earth, much difficulty and divergence
of opinion existed respecting the active cause that
set these materials on fire. Lister's suggestion had
the merit of being a vera causa, from which un-
doubtedly the spontaneous combustion of carbonaceous
strata has often arisen.
To geologists perhaps not the least memorable of
Lister's contributions to the progress of science was
a proposal made by him for the first time for the
construction of what we now call geological maps.
This subject will be more particularly referred to in
Chapter XIV.
Robert Plot in his Natural History of Oxfordshire
(1677) described Nature's "extravagancies and defects,
occasioned either by the exuberance of matter or
obstinacy of impediments, as in monsters ; and then
lastly as she is restrained, forced, fashioned or deter-
mined by artificial operations." Though he gave a
map and sixteen beautifully engraved plates which
included representations of fossils, he stated seven
reasons for rejecting the idea that the fossils " owed
their form and figure to the shells of the fishes they
represent " and for concluding that these objects or
c< formed stones " must be regarded as u lapides sui
generis, naturally produced by some extraordinary plastic
virtue, latent in the earth, or quarries where they are
found." !
With these writers may here be included the Celtic
scholar and antiquary, Edward Lhuyd (1660-1709) who
1 O/. clt. 2nd Edit. (1705), p. 112.
78 Edward Lhuyd
published a Latin treatise in which he gave excellent
plates of a thousand fossils preserved in the Ash-
molean Museum, Oxford. He was a valued corre-
spondent of Ray, who quotes him as suggesting that
the fossils enclosed within rocks might possibly be
" partly owing to fish-spawn received into the chinks
of the earth in the water of the Deluge," and as
speculating " whether the exhalations which are raised
out of the sea, and falling down in the rains, fogs,
etc., do water the earth, to the depth here required,
may not from the seminium or spawn of marine
animals, be so far impregnated with, as to the naked
eye invisible, animalcula (and also with separate or
distinct parts of them), as to produce these Marine
Bodies, which have so much excited our admiration,
and indeed baffled our reasoning, throughout the
globe of the earth." 1
1 Ray, Three Physico-Theological Discourses (1721) p. 190. In the
long letter from which these sentences are taken Lhuyd brings
forward a number of shrewd arguments against ascribing fossil
shells and plants to Noah's Flood.
CHAPTER III
SCIENTIFIC Cosmogonists Descartes, Leibnitz. Speculations of De
Maillet and Buffon. Early illustrated works on fossil plants and
animals Lang, Scheuchzer, Knorr, Walch, Beringer.
FROM the middle of the seventeenth to the middle of
the eighteenth century there appeared at intervals on
the Continent a series of cosmogonists of a very dif-
ferent stamp from those alluded to in the last chapter.
They were men who took a broad view of the world
and endeavoured to trace its origin and progress in the
light of what was then known of the laws of Nature.
The earliest of these illustrious writers was the dis-
tinguished philosopher Descartes (1596-1650) who,
in his Philosophiae Principia, published in 1644, gave
an exposition of what he conceived to have been
the origin and history of our globe. He supposed
the various planetary bodies to have been originally
glowing masses like our sun. The earth in his view
consists of three distinct regions. In its centre lies
a nucleus consisting of incandescent self-luminous
matter, like that of the sun. The middle zone is
composed of an opaque solid substance which was at
first very liquid. The outer region, comprising all the
materials of which we have actual cognisance, consists
8o Cosmogony of Descartes
of the debris of the clouds or spots which, like those
of the sun, gathered on the surface of the globe while
still an intensely hot body. These spots were no
doubt again and again melted down as they formed,
until the whole globe had cooled sufficiently to allow
them to aggregate into a solid external crust. The
outer region of the planet, as the earth drew towards
the sun, separated into different portions that arranged
themselves one above another, according to their relative
densities, the atmosphere being uppermost, then the
water, while below these the more solid matter took
the form of an outer layer of stone, clay, sand and
mud, and an inner more solid and heavy layer whence
all the metals come. Descartes supposed that the heat
and light of the sun could penetrate into the innermost
parts of the earth and there, during day and summer,
in the early stages of the planet's history, exerted so
potent an influence as to lead to the rupture of the
outer crust, of which some projecting portions rose
above the waters and formed land.
This philosopher further suggested that certain
exhalations from the inner parts of the earth turn into
oil, but when they are in a state of violent motion and
in that condition enter cavities or fissures which pre-
viously contained air, they pass into a heavy thick
smoke, like that of a newly extinguished candle.
When a spark of fire is excited in these places the whole
of the smoke bursts into flame, and becoming suddenly
rarefied presses with great violence against its con-
taining walls, especially when it includes a quantity
of volatile salts and spirits. Hence arise earthquakes.
It sometimes happens also that the flame which causes
Leibnitz 8 1
earthquakes breaks open the top of a mountain and
issues thence in great volume, hurling forth much earth
mingled with sulphur or bitumen. These mountains
may continue to burn for a long time, until all the
sulphur or bitumen is consumed. Descartes thought
that the subterranean fires might be kindled by the
spirits inflaming the exhalations, or by the fall of
masses of rock and the consequent sparks produced by
their friction or percussion.
Still more memorable than the cosmological specu-
lations of Descartes were those of the philosopher
Leibnitz (1646-1716), whose capacious mind embraced
every department of human knowledge, and whose
acute and original genius threw new light into each.
Among the subjects that engaged his thoughts was the
problem of the origin and early history of our globe,
regarding which he propounded views that have been
accepted by the physicists of our own day. A summary
of these opinions was first promulgated by him in a
communication to the Acta Eruditorum of Leipzig,
published in 1693, but the fuller statement contained
in his remarkable treatise, the Protogaea, did not appear
till 1749, thirty-three years after his death. Like
Descartes, he believed that our planet was once a
smooth incandescent molten globe, which has ever
since been cooling, contracting and becoming rugose
on the surface. When the temperature of the outer
parts had sufficiently fallen, a glassy and slaggy crust
began to form on the outside, portions of which he
supposed to be recognisable in the primitive crystalline
rocks, such as granite and gneiss. Out of the vaporous
atmosphere, as the whole planet cooled, the water
82 Cosmogony of Leibnitz
condensed into liquid form and made the ocean, which
by washing the debris of the crust, dissolved out the
soluble ingredients and became salt. As the thickness
of the crust increased, its solidification was accompanied
by the formation of immense cavities containing air
or water, the roofs of which, when they sank down,
would form valleys, while the other more solid parts
would rest like columns and give rise to mountains.
By the disruption of the crust, whether owing to its
weight or to gaseous explosions, vast inundations would
be produced which rushing over the face of the globe
would sweep a great amount of sediment together
and allow of the accumulation of sedimentary forma-
tions. Thus the face of the earth would be often
renovated until, as the various disturbing forces quieted
down and become more equable in their action, a
more stable condition of things (consistentior rerum
status] arose. In these reactions Leibnitz clearly re-
cognised the working of the two great classes of
geological causes, in the first place the internal
heated nucleus whence igneous rocks proceed, and in
the second place, the superficial waters whereby hollows
are eroded on the earth's surface and sedimentary rocks
are formed.
As if he considered their obvious connection with
the internal fire a sufficient explanation of their occur-
rence, Leibnitz passes briefly over the subject of
earthquakes and volcanoes. Yet he seems still to
entertain the old notion that actual combustion takes
place as part of these subterranean disturbances, for
in alluding to the underground fires that feed vol-
canoes, he mentions the deposits of stone-coal and
Leibnitz on Fossils 83
sulphurous materials, native sulphur, and springs of
naphtha, and remarks "it is not unreasonable to
believe that since the Deluge there have been partial
fires, the date of which is not known, but which
occurred at a time when combustible substances were
more plentifully distributed in the thickness of the
earth than they are now."
A considerable part of the Protogaea is devoted to
a discussion of the evidence from organic remains
enclosed in the sedimentary formations. In showing
how perfectly and in what minute detail the struc-
ture of fishes and other organisms is reproduced in
these fossils, Leibnitz ridicules the absurdity of calling
them " sports of Nature," and points out how much
more willingly we should admit the operation of an
obvious and regular cause than a mere game of chance
or other fanciful suggestion, under which the conceited
ignorance of the learned had taken shelter. He insists
on discriminating between the polygonal forms of
crystals and the shapes of fossils, which had all been
classed as arising from the same plastic force, and he
complains of the facile credulity which could bring men
not only to confound these utterly distinct things, but
to believe that Nature could have manufactured within
the rocks historical and mythological pictures, such as
Apollo and the Muses in veins of agate, the pope and
Luther in the stone of Eisleben, and sun, moon and
stars in marble.
Leibnitz takes note of the astonishment expressed
by some writers that for many of the " figured stones "
no analogies had been discovered in the living world of
to-day, or at least in the regions where these objects are
84 Benoit de Mail let
found. He asks in reply whether any one had yet
explored the depths of the ocean, or how many animals,
hitherto unknown, remained still to be discovered in
the New World. " Is it not to be presumed," he
enquires, "that in the great changes which the earth
has undergone a great many animal forms have been
transformed ?" After describing a number of instances
in which a succession of strata has been ascertained
to contain different platforms of organic remains, point-
ing to advances and retreats of the sea, he concludes his
treatise with these words : " Thus Nature fills for us
the place of history ; while on the other hand, our
history pays back to Nature this service, that it takes
care that her illustrious works, so far as we have been
able to perceive them, shall not remain unknown to our
posterity." x
We have now to notice the work of a writer of an
utterly different type from the two philosophers just
spoken of. Though hardly deserving to be regarded
as a man of science, Benoit de Maillet (1656-1738),
French diplomatist and traveller, was a keen and
shrewd observer of Nature, and his speculations were
not without their influence on the progress of geology.
In the course of his long life he saw much of the
countries bordering both sides of the Mediterranean
basin, and gathered together stores of information
regarding the physical aspect and historical changes
in the surface of these countries. Being led to
speculate on the probable origin and future fate of
this globe and its inhabitants, he arrived at conclu-
sions which were at least conspicuously unorthodox.
1 Protogaea, p. 86.
The Telliamed 85
In committing them to paper he ingeniously contrived
to put them into the mouth of an Indian philosopher,
but even with this precaution he did not venture to
publish them, and his treatise only saw the light at
Amsterdam in 1748, ten years after his death. It
bore the title of Telliamed [his own name spelt
backwards] ou Entretiens dun Philosophe Indien avec
un Missionaire Fran^ais.
The main purport of the book is to demonstrate
that this globe was once completely surrounded with
water, which has been gradually disappearing and will
continue to diminish, until the planet is desiccated
and is finally burnt up by the outbreak of volcanic
forces from within. We cannot doubt, so the author
believed, that this globe is the work of the sea and
has been formed in its bosom, in the same way that
similar formations are even now deposited in its
waters. All mountains consist of sand, mud or
other sedimentary materials, and have been formed
by the sea. The oldest and highest are composed
of a simple and uniform substance, in which few
or no traces of animal life have been preserved.
As the sea, in its subsidence, laid bare the summits
of these earliest mountains, the waves beat on their
sides, and the materials of new mountains were thus
obtained, in which organic remains became increas-
ingly abundant. That the various sediments should
be arranged one above another in successive strata,
is shown to be what might be expected from the
action of the sea along its coasts and over its
bottom at the present time. Emphasis is laid on
the prodigious abundance of marine fossils from
86 Telliamed on Retreat of the Sea
below sea-level up to the mountain tops as proof
of the former submergence of the land and of the
mode in which the rocks of the land have been
formed. The author sagaciously calls attention to
the fact that, instead of being indiscriminately huddled
together in the strata, the fossils are found to lie on
the planes of stratification, just as the shells and
other organisms of the present sea are strewn over
the surface of the sea-floor.
Telliamed, the Indian Philosopher, ridicules the
notion that these universal marine formations could
have been laid down by Noah's Flood, which he
affirms was a local and transient inundation. He
asserts that the valleys and other hollows of the
earth's surface have been scooped out by marine
currents during the sinking of the sea, leaving the
mountainous ridges standing up between them. The
diminution of the water is regarded by him as due
to evaporation, whereby the vapour is carried through
space to the extremity of the vortex wherein the
dust and the particles of water are once more con-
densed upon other globes.
Methods are described for measuring the rate of
the lowering of the sea-level, and as the result of ob-
servation it is estimated that the diminution amounts
to as much as three or four inches in a century, or
about three feet in a thousand years. A time will
come when the Black and Mediterranean seas will be
isolated into lakes, like the Caspian, and when the
Atlantic will be laid dry, save perhaps some restricted
remnant in its deeper part, while the rivers of the
Old and New World will mingle their waters together.
Telliamed on Animal Evolution 87
Volcanoes, in the cosmogony of Telliamed, are due
to the combustion of the oils and fats of the various
animals entombed in the sediments of which the
mountains have been formed. These volcanoes, by
communicating with each other, will ultimately ex-
tinguish all life, and finally lead to the total con-
flagration of our globe, which will then become a
true sun, until having consumed all the combustible
material that maintained this prodigious heat, it will
once more cool down and become opaque.
But the most curious speculations of Telliamed
are those in which he discusses the problem of the
origin of the various races of animal life. He supposes
the plants and animals of the land to have been
derived from those of the sea. But the data which
he advances in support of his notions of evolution
seem to us now almost childishly absurd. He speaks
of rose-trees which had their blooms quite red when
they were taken out of the sea. He affirms that
there exist on land no walking, flying, or creeping
creatures which have not their analogues in the sea,
and that their transference from one region to the
other is not only probable but can be proved by
a vast number of actual examples. He illustrates
what he conceives to be the natural course of trans-
formation by picturing flying fishes which somehow
should fall among reeds or rushes and be unable to
resume their flight. Their exertions would increase
their aptitude to use their wings, but the dry air
would split these membranes and raise up the scales
of their bodies into a kind of down, the little fins
under their belly, which once helped them to swim,
88 Buff on
would now become feet which would enable them ta
walk on the land. Then follows an account of seals,
sea-dogs, and the origin of man, wherein the author
states that he will scrupulously reject everything which
might be regarded as fanciful, and that he will confine
himself to well-attested and recent facts. He then
gravely recites a number of tales of mermen and
mermaids, of savage dumb men, like apes, of men
with tails, of giants and dwarfs, and he comes to
the conclusion that as all the species of mermen are
still unknown, it is not yet possible to trace from
which of them the various races of mankind have
been derived. He sees no difficulty in the transition
of men from the water to the air, and thinks that
this passage is easiest in polar regions, where probably
the transformation of mermen into ordinary men is
always most common.
The last and not the least eminent of the cos-
mogonists who may be cited in this retrospect is the
illustrious naturalist G. L. Leclerc de Buffon (1707-
1788) one of the great pioneers in science who figure
so conspicuously in the history of France. At first
he interested himself in physics and mathematics, but
gradually widened his outlook, and conceived broad and
profound ideas regarding the whole realm of Nature.
Endowed with a spirit of bold generalisation, and
gifted with a style of singular clearness and eloquence,
he was peculiarly fitted to fascinate his countrymen,
and to exercise a powerful influence on the scientific
progress of his age. He is the central figure in a
striking group of writers and observers who placed
France in the very front of the onward march of
Buffons Theory of the Earth 89
science, and who laid some of the foundation-stones
of modern geology.
The introductory portion of Buffon's voluminous
Natural History was devoted to a Theory of the Earth.
Though written in 1744, it was not published until
1749. The author had meditated long and deeply on
the meaning of the fossil shells found so abundantly
among the rocks of the earth's crust, and had recog-
nised that, as they demonstrate the condition of the
globe not to have been always what it is now, any true
theory of the earth must trace the history of the
planet back to a time before the present condition
was established. Like Descartes and Leibnitz, he
saw that this history must be intimately linked with
that of the solar system, of which it formed a part.
He thought that the various planets were originally
portions of the mass of the sun, from which they
were detached by the shock of a comet, whereby the
impulse of rotation and of revolution in the same
general plane was communicated to them. In com-
position, therefore, they are similar to their parent
sun, only differing from that body in temperature.
He inferred that at first they were intensely hot and
self-luminous, but gradually became dark as they
cooled, the central sun still remaining in a state of
incandescence.
Though the hypothesis of a cometary shock is not
now entertained, it is impossible to refuse our admira-
tion to the sagacity of a man who tried to solve the
problem of planetary evolution by the application of
the laws of mechanics. The geological portion of his
theory, however, was loaded with several crude con-
90 Bufforis Epoques de la Nature
ceptions. The enormous numbers and wide diffusion
of fossil shells, which had so vividly impressed his
imagination, proved to him that the land must have
lain long under the sea. But he had no idea of any
general cause that leads to elevation of the sea-bottom
into land. He was thus constrained to resort to his
imagination for a solution of the problem. Burnet
had supposed the original ocean to be contained within
the earth, and that it only escaped at the time of
the Flood, when, by the heat of the sun, the crust
of the globe had cracked, and thus allowed the pent-
up waters to rush out. Buffon's theory was hardly
less fanciful. But he reversed the order of events.
He inferred from the abundance of fossil shells that
there had once been a universal ocean, and that by
the giving way of the crust, a portion of the waters
was engulfed into caverns in the interior, so as to
expose what are now mountains and dry land.
For some thirty years after the publication of his
Theory^ Buffon continued to work industriously in all
departments of natural history. At last, in 1778,
having long meditated on the problem of the origin
of the earth, he published his famous Epoques de la
Nature. In this work he arranged the history of the
globe in six epochs intervals of time of which the
limits, though indeterminate, seemed to him none the
less real. He tried indeed to form some idea of their
duration on the basis of a series of ingenious experi-
ments with globes of cast-iron of different sizes, and
though the method on which he proceeded could not
give him reliable results, and his estimates have ac-
cordingly no scientific value, they possess the highest
Buffon on Book of Genesis 91
historical interest, first as the earliest recorded attempt
to compute the probable age of the earth and of the
planets from physical observations, and secondly as an
epoch-making departure from the old and orthodox
notion that our globe came into existence only some
six thousand years ago. In discussing the Biblical
narrative of the Creation, Buffon boldly asks what we
can possibly understand by the six days, if not six
periods of time or intervals of duration. Though
referred to in the Book of Genesis as days, for want
of another term, they can have no relation to our
actual days, seeing that no fewer than three of them
had passed away before the sun was fixed in the
firmament. " The sense of the narrative seems to
require that the duration of each ' day ' must have
been long, so that we may enlarge it to as great an
extent as the truths of physics may demand." 1
The First Epoch embraced the primeval time when
the earth, newly torn from the sun, existed still as
a molten mass which, under the influence of rotation,
assumed its oblate spheroidal form. The transition
from fluidity to solidity, and from luminosity to opacity
was brought about entirely by cooling, which com-
menced at the outer surface. A crust was thus formed,
outside of which the substances still in a vaporous
condition, such as air and water, remained as a hot
aeriform envelope, while the interior still continued
liquid. The period of incandescence before the globe
consolidated to the centre was computed by Buffon
to have amounted to 2936 years while the period
during which the surface remained too hot to be
1 Histoire Naturelle, tome in. p. 204.
92 Bufforis Epochs of Earth-history
touched, and therefore unfit for living beings, com-
prised about 35,000 years.
The Second Epoch was characterized by the con-
solidation of the molten globe, and the appearance of
hollows and ridges, gaps and swellings, over its surface,
and cavernous spaces in its interior, such as may be
seen in a globe of fused metal after it has cooled.
These inequalities in the crust of granite, gneiss and
other ancient crystalline rocks, gave rise to the earliest
or primitive mountains and valleys of the higher
portions of the land. During the process of con-
solidation, cracks arose in which metalliferous veins
were formed by sublimation or fusion. Up to the
end of this period, the globe remained intensely hot
and its water still existed only among the vapours of
the atmosphere.
The Third Epoch, which began about 35,000 years
after the birth of the earth, included the time when
the waters were condensed so as to descend and
remain on the sufficiently cooled surface of the globe.
So vast was the sea at first that its surface stood from
9000 to 12,000 feet higher than it does now, as was
supposed to be indicated by the heights at which
marine organisms are found in the rocks of the moun-
tains. The waters were at first boiling, and as they
cooled, animal life was introduced into them. This
life must have been in many ways different from that
of our present seas. The oldest species, which are
nowhere now to be found alive, flourished during the
first ten or fifteen thousand years after the seas had
been gathered together. If a collection of fossils were
made from the highest parts of the mountains, Buffon
Buff on s Epochs of Earth-history 93
thought that it might be possible to decide as to the
relative antiquity of species. Nature was then, as it
seemed to him, in her first vigour, and fashioned larger
types of life than now survive. When the earliest
condensation of water took place upon the still warm
surface of the globe, great corrosion of that surface was
effected. The decomposed rocks gave rise to much
clay, which was washed off into the sea, there to form
the various argillaceous sediments now to be seen on
the land. As life increased in the sea, the calcareous
fossiliferous formations were deposited which consti-
tute so much of the existing land. Buffon supposed
that the sea in which all the fossiliferous strata were
accumulated must have covered the land for at least
20,000 years. The parts of the earth's surface that
rise into land were now covered with dense forests.
The Fourth Epoch witnessed the emergence of the
lower part of the land, owing to the sinking of the
waters through cracks into cavities in the interior of
the globe. Buffon estimated that 20,000 years were
required for the lowering of the sea from its original
to its present level. Profoundly as he had meditated
on the structure of the earth, he had during thirty
years made no advance in his views of the origin of
the dry land, nor had he obtained any more light on
volcanic phenomena than his predecessors had possessed.
He estimated that a hundredth or a two-hundredth
part of the surface of the earth was covered with
dense vegetation, and that vast quantities of this
vegetation were swept down into the lower places of
the earth's surface and into the fissures of the rocks.
He supposed that meeting there with the substances
94 Bufforis Epochs of Earth-history
sublimed by the great internal heat these carbonaceous
accumulations would form the first provision of
aliment for the volcanoes which were now to make
their appearance. Volcanic energy, in his view, arises
from " the effervescence of the pyritous and com-
bustible stones/' combined with the effective co-
operation of subterranean electricity, which he believed
to be likewise a powerful agent in the production of
earthquakes. Volcanoes, however, can only become
active by " the conflict of a great mass of water with
a great body of fire." Hence they are always near
the sea. BufFon computed that the first volcanoes did
not arise until some 50,000 years of the earth's history
had elapsed, by which time a sufficient quantity of
combustible materials had been accumulated to furnish
them with fuel, and he drew a graphic picture of the
frightful condition of our planet when its surface was
at once ravaged by fire and devastated by debacles
of water. Only after the cessation of such turmoil
could terrestrial animals come into being. During this
period the retreating waters of the ocean gave birth
to powerful currents, whereby hollows were scoured
out of the still comparatively soft sedimentary strata,
and thus were originated the valleys of the land
which have subsequently been widened and deepened
by subaerial denudation.
The Fifth Epoch was marked by a calmer time
which witnessed the advent of huge pachyderms
elephants, rhinoceroses, and hippopotamuses in the
northern regions, where at that time a warm climate
stretched continuously from Asia and Europe into
America. This introduction of terrestrial animal life
Buff on s Epochs of Earth-history 95
is placed by Buffon 55,000 or 60,000 years after
the beginning of the world, or about 15,000 years
before our own time.
The Sixth Epoch was marked by the separation of
the two continents of the Old and New Worlds,
which, as was inferred from the presence in each of
them of what were supposed to be the same fossil
mammals, were believed to have been originally united.
Buffon placed this event 10,000 years before his time.
The same period also saw the submergence that
isolated Greenland from Europe, Canada and New-
foundland from Spain, and gave rise to so many
insular tracts in the north Atlantic. The history of
other late topographical features of the earth's surface,
such as the Mediterranean, the Bosphorus, and the
Black Sea, is next sketched, and is connected with
the occurrence of successive deluges and ruptures of
land-barriers.
Buffon added a seventh epoch, in which he traced
the commanding influence of man in modifying the
surface of the earth.
Recognising the powerful agency of rivers and the
sea in washing away the materials of the land, he
believed that by this action the whole of the existing
continents will finally be reduced and covered by the
ocean ; and he conceived that by the same series of
changes new lands will ultimately be formed. He
foresaw, however, the final extinction of our globe as
a habitation for sentient beings, but not after the
manner of the orthodox creed that the heavens and
the earth are at last to melt with fervent heat. Buffon
recognised proofs of the gradual refrigeration of our
96 Character of Buff on s Cosmogony
planet and he estimated that this process would con-
tinue for yet 93,000 years by which time the globe
would have become colder than ice. Then this
beautiful Nature, which with its tribes of plants and
animals, will have existed for 132,000 years, will
perish.
In breadth and grandeur of conception BufFon far
surpassed the earlier writers who had promulgated
theories of the earth. The rare literary skill with
which, in his masterpiece, the Epoques, he presented
his views, enabled him to exercise a powerful influence
on his contemporaries, to direct their attention to the
deeply interesting problems of which he wrote, and to
give to natural science a far wider popularity than it
had before enjoyed. If looking back from our present
knowledge, we may be inclined to regard his eloquent
pages rather in the light of a pictorial vision of what
his brilliant imagination bodied forth as the origin of
things, than a sober attempt to work out a theory
on a basis of widely collected, carefully sifted and
systematically co-ordinated facts, we must remember
that science had not yet advanced far enough to pro-
vide such a basis. It was his great merit to have
pointed out that the history of our earth is a long
chronological record, the memorials of which are to
be read in the frame-work of the globe itself, and to
have himself applied the historical method to its inter-
pretation. Nor were his services less conspicuous in
breaking down the theological barrier which, after so
many centuries, still blocked the way towards a free
and unfettered study of the crust of the earth. So
powerful in his time did the ecclesiastical authorities
Buffon and the Sorbonne 97
continue to be, that we are told how, though the
Epoques was a work on the preparation of which he
had spent much time and thought and which he longed
to publish, he had cautiously to feel his way and pay
court to some of the doctors of the Sorbonne, and how
it was only after having secured, if not the votes, at
least the silence of the majority of a corporation which
tyrannised over thought, that he ventured to send his
treatise to the printer. His friends, however, remained
anxious on his account, until whether because religious
intolerance was growing less with the advance of
science, or because the clerical powers were satisfied
with professions of faith and protestations of belief
on the part of the author, the work was allowed to
pass peaceably on its way to popularity. Although
this treatise shows that the long interval of thirty years
after the appearance of the Theorie had given greater
freedom and had still further enlarged his views of
nature, he was evidently unaware of much that had
been observed and described during that interval by
his own countrymen and in other parts of Europe.
In particular he does not seem to have been acquainted
with the progress that had been made in evolving a
stratigraphical succession among the fossiliferous for-
mations in Germany, Italy, and England. One would
hardly suppose from his chapters that so much infor-
mation had now been amassed regarding fossil organic
remains.
The prolonged controversy over the nature and
origin of the " figured stones " had this good result
that it not only drew general attention to these objects,
but developed a passion for collecting them, and thus
9 8 K. N. Lang and J. J. Scheuchzer
led to the formation of numerous cabinets or museums
wherein they found a conspicuous place among other
illustrations of natural history. They were likewise
made the subject of description in an increasing num-
ber of treatises, and of delineation on engraved plates,
although the question was still hotly disputed whether
these objects should be considered as mere sports of
Nature or as relics of once living things and memorials
of the Deluge. Reference was made in the last chapter
to one or two of the oldest of these collections of
fossils, and to the earlier illustrated works in some of
which the fossils were treated as mere " figured stones."
After the appearance of the volumes by Lister and
others in England, Switzerland became the birthplace
of a number of treatises on the subject written, some
in Latin and others in German. One of the earliest
of these, the Historia Lapidum Figuratorum Helvetia*
of K. N. Lang was published in 1708 at Venice, and
contained a crude classification of these objects, in
which minerals, concretions and fossil remains of
animals and plants were all included. This author,
though he recognised the resemblance of some of the
fossil shells to species now living, believed that their
germs were transported as fine dust from the ocean and
germinated among the rocks.
More important were the treatises of J. J. Scheuch-
zer (1672-1733) of Zurich. In the year 1702 this
writer published a work with the title Specimen Litho-
graphic Heheticae curiosc, in which he described
<c figured stones " as sports of Nature. But having
afterwards procured a copy of Woodward's Essay,
which he translated into Latin, he adopted the opinion
Scheiichzers " Fossil Man " 99
that these stones are relics of the Deluge, and upheld
this view in his subsequent writings. He was a most
active observer and prolific author. His Natur-Historie
des Schweizerlandes is a remarkable dissertation, in which
the climate, topography, hydrology (including glaciers),
meteorology and mineralogy of the country are well
described. There is a section devoted to " Relics of
the Deluge found in Switzerland," wherein are de-
scribed a number of fossil plants and shells, concluding
with a paragraph on " Men." At that time he con-
fesses that so rare were human remains in the fossil
state that none had yet turned up in his own country,
unless he might include the gigantic bones found in
Canton Lucerne, though he hopes that some will be
found at such time as God may please. This hope he
thought was at last realised towards the end of his
life by the discovery at Oeningen of a skeleton which
he had no doubt was a relic of " one of the infamous
men who brought about the calamity of the Flood."
He took some pains to let the world know of this
important discovery. Thus in a Latin letter to Sir
Hans Sloane, to be communicated to the Royal Society
of London, into which body Scheuchzer had been
elected, he gave a brief description of the specimen,
and estimated the stature of the fossil man to have
been about the same as his own, or 58 J Paris inches.
A fuller account formed the subject of his famous tract,
Homo Diluvii Testis (1726). This celebrated specimen,
afterwards shown by Cuvier to be not a human skele-
ton, but that of a large salamander, is now preserved
in the Teyler Museum at Haarlem.
Scheuchzer wrote a useful catalogue of the names
ioo Scheuchzers Humour
which up to his time had been given to the ct figured
stones " (Sciagraphia Lithologica Curiosa ; sen Lapidum
Figuratorum Nomenclator\ and gave references to some
of the published descriptions of them. He was like-
wise the author of a Herbarium Diluvianum, containing
a series of fourteen good plates of fossil plants,
together with some corals and other plant-like organ-
isms. As a further indication of his connection with
England and the Royal Society, it may be mentioned
that the first of these plates is inscribed to the Arch-
bishop of Canterbury, and the second to Sir Isaac
Newton.
To one further treatise of the Zurich professor
reference may here be made for the quaint humour
which runs through it. It is a thin small quarto
in Latin, with the title Piscium Qiuerel<e et Vindicite^
1708. The fossil fishes are represented as assembled
in council to protest against their treatment by the
descendants of the wicked men that brought on the
Flood by which these very fishes had been entombed.
They discourse of " the irrefragable witness of the
universal Deluge which by the care of Providence
their dumb race places before unbelievers for the
conviction of the most daring atheists," Specimens of
their fossil brethren are appealed to pike, trout, eel,
perch, shark and their well-preserved minute struc-
ture of teeth, bones, scales and fins is pointed to as a
triumphant demonstration that such perfect anatomical
detail could be fabricated by no inorganic process
within the rocks, as had been maliciously affirmed.
It was from Nuremburg that the most important
work on fossils was issued during this period. Among
G. W. Knorr and J. E. I. Walch 101
the natives of that quaint old town, George Wolfgang
Knorr (1705-1761), who followed the occupation of
an engraver, developed such an enthusiasm for natural
history objects that he specially devoted himself to
the preparation of finely-engraved plates, for the illus-
tration of works on botany and conchology, as well
as on art. In the end, he began to collect fossils, and
to prepare engravings of them and of other specimens
contained in some of the cabinets which were now
becoming numerous all over Europe. It was his
intention to publish a treatise on the subject fully
illustrated by himself. He had completed the first
volume, but died before any further portion of the
work was ready. It is hardly possible to exaggerate
the beauty and fidelity of the representations of the
fossils in his plates. No such illustrations had ever
before appeared, and they have hardly been surpassed
since. By delicate lines on the copper plates the most
minute intricacies of structure are reproduced, and by
thin washes of colour the tints of the original speci-
mens are represented. His renderings of dendritic
markings, landscape-marble, fossil plants, Crustacea,
crinoids, fishes and other fossils are admirable examples
of the union of artistic workmanship with scientific
accuracy. Fortunately for Knorr's reputation and the
progress of science, another enthusiast was ready to
take up the work where the Nuremburg artist had
left it. J. E. I. Walch (1725-1778) who held the
appointment of Professor of Eloquence and Poetry
in the University of Jena, was also a collector and
student of minerals, rocks and fossils, and in 1762
published an excellent little volume, Das Steinreich y
102 J. B. Beringer
which gives a rough classification of rocks according
to their structure, such as Granular, Lamellar, and
Filamentous. He was prevailed upon by Knorr's
executors to undertake the continuation and publi-
cation of the work of the deceased artist. As a large
amount of the materials for the plates had already
been arranged by Knorr, the hands of the continu-
ator were rather tied in regard to the treatment of
the subject. But Walch with remarkable industry and
perseverance pursued his task until four folio volumes
of text and nearly 300 plates had been completed and
published under the title of Lapides Diluvii Vniversalis
Testes Sammlung von Merckwurdigkeiten der Natur zum
Beweh einer allgemeinen Sundfluth. The fourth and
last volume containing Systematic Tables and an
Alphabetical Index, affording a guide to the contents
of the whole work, was published in 1778. In spite
of the diluvial creed of the authors, this fine publi-
cation marks a notable advance in the palaeontological
department of geology. It presents an instructive
and detailed statement of all that was known on the
subject at the time, with abundant references to the
writings of previous authors.
The craze for collecting u figured stones " and other
mineral curiosities, together with the ignorant credulity
of many of the collectors, led to the occasional per-
petration of practical jokes. One of the most famous
instances of this tendency was that of the tricks played
off upon the learned Wiirtzburg Professor, J. B.
Beringer, who, having with great enthusiasm and with
the help of his students made a collection of fossils
from the Triassic strata of his neighbourhood, published
J. B. Beringer 103
in 1726 an illustrated work upon his discoveries.
Among the objects depicted by him were figures of
celestial bodies, and other remarkable things which
he unsuspectingly regarded as of equal significance.
When, however, his youthful companions went so
far as to manufacture still more grotesque " figured
stones/' and dropped them in the quarries into which
they led him that he might himself discover them ;
and more especially when, at last, besides Hebrew
letters, he found his own name inscribed on the stone,
the truth dawned on him that he had been hoaxed.
He did his best to buy up the edition of his work
in which so many of the tricks had been unsuspect-
ingly figured and described. But some copies still
survive, and examples of the manufactured fossils
are preserved in the museums of Wiirtzburg and
Munich.
CHAPTER IV
THE rise of Geology in France. Palissy. The labours of GuettarcL
WHILE in England, Switzerland, Italy, and Germany
the study of fossils was making progress in spite of
the controversies to which the subject gave rise, in
France for a time less advance could be perceived. It
is true that as far back as 1580 the celebrated ceramic
artist Bernard Palissy had published some important
observations on the petrifaction of wood, as well as on
shells and fishes in the rocks, and had called attention
to these objects in proof of the former presence of the
sea or of lakes, where such organic remains are now
found. But it was not until the early part of the
eighteenth century that France produced a man worthy
to stand in the front rank of the early founders of
geology and of whose career some detailed notice
may here be given. While Buffo n was indulging in
his brilliant speculations as to the origin and history
of the earth there lived in Paris at the same time
a student of Nature, belonging to a totally different
type, who, shunning any approach to theory, dedicated
himself with the enthusiasm of a true naturalist to
the patient observation and accumulation of facts
regarding the rocks of the earth's crust, and to whom
Jean Etienne Guettard 105
modern geology owes a deep debt of gratitude, that
has never yet been adequately paid. This man, Jean
Etienne Guettard (1715-1786), was born in the year
1715 at the little town of Etampes, about thirty miles
S.W. from Paris. 1 As the grandson of an apothecary
there, he was destined to succeed to the business of
compounding and selling drugs. Before he left home
for his professional education, he had already developed
a passion for natural history pursuits. When still a
mere child, he used to accompany his grandfather
in his walks, and his greatest happiness was found in
collecting plants, asking their names and learning to
recognize them, and to distinguish their different parts.
Every nook and corner around Etampes became
familiar to him, and in later years he loved to revisit,
with the eye of a trained naturalist, the scenes which
had fascinated his boyhood. In his writings he loses
no opportunity of citing his native place for some
botanical or geological illustration. Thus, at the very
beginning of a long and suggestive memoir on the
degradation of mountains, to which further reference
will be made in the sequel, his thoughts revert to
the haunts of his infancy, and the first illustration he
cites of the processes of decay which are discussed in
that paper is taken from a picturesque rock overlook-
ing the valley of the Juine, under the shade of which
he used to play with his companions. 2
1 For the biographical facts here given I am indebted to the Eloge of
Guettard by Condorcet (CEuvres, edit. 1847, vol. iii. p. 220) and to
the personal references which I have met with in Guettard's writings.
2 Memoir es sur differ entes parties des Sciences et des Arts, tome iii.
p. 210 (1770).
106 Guettard
Having gained the favourable notice of the famous
brothers Jussieu, who gave renown to the botanical
department of the Jardin des Plantes, he was allowed
by his grandfather to choose a career that would
afford scope for his ardour in science. Accordingly
he became a doctor in medicine. Eventually he was
attached to the suite of the Duke of Orleans, whom
he accompanied in his travels, and of whose exten-
sive natural history collections he became custodian.
On the Duke's death he enjoyed from his son and
successor a modest pension and a small lodging in
the Palais Royal at Paris.
It was to botany that his earlier years of unwearied
industry were mainly given. In the course of his
botanical wanderings over France and other countries,
he observed how frequently the distribution of plants
is dependent upon the occurrence of certain minerals
and rocks. He was led to trace this dependence from
one district to another, and thus became more and
more interested in what was then termed " mineralogy,"
until this subject engrossed by far the largest share
of his thoughts and labours.
But Guettard was more than merely a mineralogist.
Although the words "geology" and "geologist" did
not come into use for half a century later, his writings
show him to have been a geologist in the fullest sense
of the word. He confined himself, however, to the
duty of assiduous observation, and shunned the
temptation to speculate. He studied rocks as well
as minerals, and traced their distribution over the
surface of Europe. He observed the action of the
forces by which the surface of the land is modified,
His early training 107
and he produced some memoirs of the deepest interest
in physiography. His training in natural history
enabled him to recognize and describe the organisms
which he found in the rocks, and he thus became
one of the founders of palaeontological geology. He
produced about 200 papers on a wide range of subjects
in science, and published some half-dozen quarto
volumes of his observations, together with many
excellent plates.
It is astonishing that this man, who in his day
was one of the most distinguished members of the
Academy of Sciences of Paris, and who undoubtedly
is entitled to rank among the few great pioneers of
modern geology, should have fallen into complete
oblivion in English geological literature. I shall have
occasion to show that the process of ignoring him
began even in his lifetime, and that, though free
from the petty vanities of authorship, he was com-
pelled in the end to defend his claim to discoveries
that he had made. After his death he was the subject
of a kindly and appreciative ttoge by his friend
Condorcet, the perpetual Secretary of the Academy. 1
His work was noticed at length in the great Encyclo-
pedic Mhhodique of Diderot and D'Alembert, published
thirteen years after he was laid in the grave. 2 Cuvier
1 (Euvres de Condorcet, vol. iii. p. 220.
2 Geographie Physique by Desmarest, forming vol. i. of the Encyclo-
pedie, and published An III (1794). The article on Guettard (by
Desmarest) gives a critical review of his work, especially of
those parts of it which bear on physical geography. The large
number and value of his observations on fossil organisms is admitted.
But his method of constructing mineralogical maps is severely
io8 Guettard
in his eloge of Desmarest gave to Guettard the credit
of one of his discoveries. 1 But his work seems to
have been in large measure lost sight of until in
1 862, 2 and again in i866, 3 the Comte d'Archiac dwelt
at some length on his services to the progress of
geology. More recently Guettard's labours have been
the theme of sympathetic comment from Ch. Sainte-
Claire Deville 4 and Aime de Soland. 5
In the geological literature of the English-speaking
countries, however, we shall search in vain for any
adequate recognition of the place of this early master
of the science. The famous classic, Conybeare and
Phillips' Outlines of the Geology of England and Wales^
contains a reference to the French observer as the
handled, and his claim to the discovery of the extinct volcanoes
of Auvergne is contemptuously rejected. The whole tone of the
article is somewhat ungenerous. The imperfections of Guettard's
work are fully set forth, but little is said of its merits.
1 Cuvier's E/oges Historiques, vol. ii. p. 354 (1819).
2 A. d'Archiac, Cours de Paleontologie Stratigraphique, pp. 284-304,.
1862.
3 A. d'Archiac, Geologie et Paleontologie, i re partie, pp. 112-118
(1866). The account of Guettard in this work is little more
than a condensation of the narrative in the author's previous
Cours. Even after these appreciative references Lecoq in his
Epoques Geologtques de F Auvergne omits Guettard's name from
the list of those he specially cites, and when he has occasion to
mention him, does so in a very grudging spirit. See his Intro-
duction, p. xiii. and vol. iii. p. 155.
4 Coup d'ceil historique sur la Geologie, pp. 311-314. (1878).
5 " Etude sur Guettard," Annales de la Societe Linneenne de Main-et-
Lolre, I3 me , 14, et i5 me annees, pp. 32-88 (1871, 1872, 1873). This
appreciative essay contains a list of Guettard's publications.
Neglect of his writings 1 09
first man who constructed geological maps. Scrope 1
and Daubeny 2 cite him for his observations in
Auvergne. But Lyell in his well-known summary
of the progress of geology does not even mention
his name.
It is difficult to account for this neglect. Possibly
it may be partly attributable to the cumbrous and
diffuse style in which Guettard wrote, 3 and to the
enormous bulk of his writings. When a man con-
tributes scores of voluminous papers to the transactions
of a learned academy ; when he publishes, besides, an
armful of bulky and closely printed quartos, and when
these literary labours are put before the world in by
no means an attractive form, perhaps a large share
of the blame may be laid to his own door. Guettard
may be said to have buried his reputation under the
weight of material which he left to support it.
I cannot pretend to have read through the whole
of these ponderous volumes. The leisure of a hard-
worked official does not suffice for such a task. But
I have perused those memoirs which seemed to me
to give the best idea of Guettard's labours, and of
the value of his solid contributions to science. And
I shall now proceed to give the results of my reading.
No one can glance over the kindly eloge by Condorcet
1 Geology and Extinct Volcanoes of Central France, p. 30, 2nd
edition, 1858,
2 Description of Active and Extinct Volcanoes, p. 729, 2nd edition
(1848).
3 Of this defect no one was more sensible than the author
himself. See his Me'moires sur dlfferentes parties des Sciences et des
Arts, tome v. p. 421.
1 1 o Guettard
without a feeling of respect and sympathy for the
man who, under many discouragements, and with
but slender means, succeeded in achieving so much
in such a wide circle of acquirement. And there is
thus no little satisfaction in resuscitating among
English and American geologists the memory of a
man in whom I trust that they will recognise one
of the founders of their science, deserving a place
not inferior to that of some whom they have long
held in honour.
And first with regard to Guettard's labours in the
domain of geographical geology, or the distribution of
rocks and minerals over the surface of the earth. I
have referred to the manner in which he was gradually
drawn into this subject by his botanical excursions.
As the result of his researches, he communicated in
1746 to the Academy of Sciences in Paris a memoir
on the distribution of minerals and rocks. 1 Having
been much impressed by the almost entire absence of
certain mineral substances in some places, though they
were abundant enough in others, he was led to suspect
that these substances are really disposed with much
more regularity than had been previously imagined.
He surmised that, instead of being dispersed at random,
they were grouped in bands which have a character-
istic assemblage of minerals and a determinate trend,
so that when once the breadth and direction of one
of these bands is known, it will be possible, even where
the band passes into an unknown country, to tell
beforehand what minerals and rocks should be found
along its course.
1 Mem. Ac ad. Roy. France, vol. for 1751.
His Mineralogical Map 1 1 1
The first sentences of his remarkable Memoire et
Carte Mineralogique are well worth quoting. " If
nothing," he remarks, " can contribute more towards
the formation of a physical and general theory of the
earth than the multiplication of observations among
the different kinds of rocks and the fossils which they
contain, assuredly nothing can make us more sensible
of the utility of such a research than to bring together
into one view those various observations by the con-
struction of mineralogical maps. I have travelled with
the view of gaining instruction on the first of these
two points, and following the recommendation of the
Academy, which wished to have my work expressed
on a map, I have prepared such a map, which contains
a summary of all my observations."
The idea of depicting the distribution of the mineral
products of a country upon a map was not original
with Guettard or the Academy of Sciences. It will be
pointed out in a subsequent chapter that, as far back
as the later years of the previous century, a scheme
of this kind was submitted to the Royal Society of
London by Martin Lister. 1 There is no evidence,
however, that this scheme was known to Guettard,
who, though he obtained a large amount of informa-
tion about English mineral products, probably derived
it all from French translations of English works. He
does not appear to have read English. Guettard in-
ferred, from his observations over the centre and north
of France, that the several bands of rocks and minerals
which he had detected were disposed round Paris as
1 The early history of geological map-making is briefly outlined in
chapter xiv. of the present volume.
1 1 2 Guettard
a centre. The area in the middle, irregularly oval in
shape, comprised the districts of sand and gravel,
whence he named it the Sandy band. It was there
that the sandstones, millstones, hard building stones,
limestones, and gun-flints were met with. The second
or Marly band, exactly surrounding the first, consisted
of little else than hardened marls, with occasional
shells and other fossil bodies. The third band, called
the " Schitose " [Schistose] or metalliferous, encircled
the second, and was distinguished by including all the
mines of the different minerals, as well as the pits and
quarries for bitumen, slate, sulphur, marble, granite,
fossil wood, coal, etc.
Having convinced himself that these conclusions
could be sustained by an appeal to the distribution of
the minerals in the northern half of France, he pro-
ceeded to put upon a map the information he had
collected. Using chemical and other symbols, he
placed a sign at each locality where a particular mine-
ral substance was known to exist. Moreover, employ-
ing a variety of engraved shading, he showed in a
general way the position and limits of the great Paris
basin. The marly band surrounding the central tract
of sandy Tertiary strata was represented as sweeping
inland from the coast between Boulogne and Dieppe,
through Picardy and the east of France to the Bour-
bonnais, where, turning westward, it reached Poitou,
and then struck northward to the coast west of the
mouth of the Seine. Though erroneously grouping
Secondary sometimes with Palaeozoic, sometimes with
Tertiary strata, and not accurately coinciding with the
modern divisions of the stratigraphical series, the map
His Mineralogical Map 1 1 3
nevertheless roughly expresses the broad distribution
of the formations.
Having put his data on the map of France, he came
to see that his three bands were abruptly truncated
by the English Channel and Strait of Dover. Carry-
ing out the principles he had established, he conjectured
that these bands would be found to pass under the sea
and to re-emerge on the shores of England. To test
the truth of this hypothesis, he ransacked the French
versions of two once famous English books Joshua
Childrey's Britannia Baconica^ and Gerard Boate's
Ireland*! Natural! Historic? He found much in these
volumes to confirm his surmise. Availing himself of
*" Britannia Baconica, or the natural rarities of England, Scot-
land and Wales, according as they are to be found in every shire,
historically related according to the precepts of the Lord Bacon."
London, 1660. A French translation was published in 1662 and
1667.
2 " Ireland's Natural! Historic, Being a true and ample description of
its situation, greatness, shape and nature ; of its hills, woods, heaths,
bogs ; of its fruitful parts and profitable grounds, with the severall
ways of manuring and improving the same ; with its heads or pro-
montories, harbours, roades, and bayes ; of its springs and fountains,
brookes, rivers, loghs ; of its metalls, minerals, freestone, marble, sea-
coal, turf and other things that are taken out of the ground. And
lastly of the nature and temperature of its air and season, and what
diseases it is free from or subject unto ; Conducing to the advance-
ment of navigation, husbandry and other profitable arts and
professions. Written by Gerard Boate, late Doctor of Physick to the
State in Ireland, and now published by Samuel Hartlib, Esq., for the
common good of Ireland, and more especially for the benefit of
the Adventurers and Planters there." It was published in London
in 1652, and was dedicated to Oliver Cromwell. A French version,
under the title of Histoire Naturelle cflrelande, was published at Paris
in 1666 (Diet. Nat. Biog., sub voc. Boate).
ii4 Guettard
the information afforded by them, he affixed to the
map of England the same system of symbols which
he had used on that of France, and roughly indicated
the limits of his bands across the south-eastern English
counties. This portion of his work, however, being
founded on second-hand knowledge, is more vague
and inaccurate than that which was based on his per-
sonal observations in France.
As an example of the painstaking earnestness with
which Guettard made his geological notes, it may be
mentioned that among the symbols he employed on
his map there was one for shells or marine fossil
bodies, and that this sign is plentifully sprinkled over
the map. His reading enabled him also to insert the
symbol on many parts of the map of England, all the
way from the Wash to Sussex. On the map of
France, he was able to introduce an additional sign
denoting that the shells were not in mere loose deposits,
but formed part of solid stone. In a second map, on
a smaller scale, accompanying the same memoir, and
embracing the whole of Western Europe from the
north of Iceland to the Pyrenees and the Mediter-
ranean, Guettard marked by his system of notation the
localities where various metals, minerals and rocks were
known to exist. In this way he brought into one
view a large amount of information regarding the
geographical distribution of the substances which he
selected for illustration.
This memoir, with its maps, seems to have gratified
the Academy of Sciences, for not merely was it inserted
in the volume of Transactions for the year, but in the
Journal or annual summary of the more important
His Mineralogical Map 1 1 5
work of the Academy, it occupies a conspicuous place.
The official record announced that a new application
of geography had been inaugurated by the author,
who, neglecting the political limits traced on maps,
sought to group the different regions of the earth
according to the nature of the substances that lie
beneath the surface. " The work of M. Guettard,"
it is further remarked, " opens up a new field for
geographers and naturalists, and forms, so to speak,
a link between two sciences which have hitherto been
regarded as entirely independent of each other." 1
I have dwelt at some length on this early work of
Guettard because of its importance in the history of
geological cartography. These maps, so far as I
know, were the first ever constructed to express the
superficial distribution of minerals and rocks. The
gifted Frenchman who produced them is thus the
father of all the national Geological Surveys which
have been instituted by the various civilised nations
of the Old and the New Worlds.
This effort in mineralogical map-making was merely
the beginning of Guettard's labours in this depart-
ment of investigation. " If you will only let me
have a proper map of France," he used to say, " I
will undertake to show on it the mineral formations
underneath." When Cassini's map appeared, it en-
abled him to put his design into execution. After
incredible exertions, during which he had the illus-
trious chemist Lavoisier 2 as an assistant, he completed
1 Mem. Acad. Roy. Sciences, 1751 ; Journal, p. 105.
2 See on the subject of Lavoisier's co-operation, D'Archiac's Paleont-
ohgte Stratigraphique, p. 290, and postea, p. 34.3.
1 1 6 Guettard
the mineralogical survey of no fewer than sixteen
sheets of the map. These labours involved journeys
so frequent and prolonged that it was estimated that
he had travelled over some 1600 leagues of French
soil. At last, finding the work beyond his strength,
he left it to his successor Monnet, by whom the
sixteen maps and a large folio of explanatory text
were eventually published. 1
It must be acknowledged, however, that Guettard
does not seem to have had any clear ideas of the
sequence of formations and of geological structure ;
at least there is no sign of any acquaintance with
these in his maps or memoir. His work, therefore,
excellent as it was for the time, contained little in
common with the admirable detailed geological maps
of the present day, which not only depict the geo-
graphical distribution of the various rocks, but express
also their relations to each other in point of structure
and relative age, and their connection with the existing
topography of the ground.
In the course of his journeys, Guettard amassed a
far larger amount of detailed information than could
be put upon his maps. From time to time he em-
bodied it in voluminous essays upon different regions.
The longest and most important of these is one in
three parts on the mineralogy of the neighbourhood
of Paris, in which, besides giving an account of the
distribution of the minerals and rocks, he pays special
attention to the organic remains of that interesting tract
of country, and figures a large number of shells from
1 Atlas et Description Mineralogiques de la France^ entrepris par ordre du
Rot par MM. Guettard et Monnet, 1780.
His Palczontological Labours 117
what are now known as the Secondary and Tertiary
formations.
His natural history predilections led him to take a
keen interest in the fossils which he himself collected,
or which were sent up to Paris from the country for
his examination. He devoted many long and elaborate
memoirs to their description, and figured some hun-
dreds of them. I may mention, as of particular
interest in palaeontological investigation, that Guettard
was the first to recognise trilobites in the Silurian
slates of Angers. In some specimens which had been
sent up to the Academy from the quarries of that
district, he observed numerous impressions of organic
remains, which he referred to sea- weeds and Crustacea.
The latter he sagaciously compared to modern crabs
and prawns. They are well-marked trilobites, and
his figures of them are so excellent that the genera,
and even in some cases the species, can easily be made
out. His representation of the large Illanus of these
Lower Silurian slates is specially good. His memoir,
read before the Academy in 1757, and published in
1762^ is thus a landmark in geological literature, for
it appeared eighty years before Murchison's Silurian
System made known the sequence and abundant organic
remains of the Silurian rocks of Wales.
Guettard's labours in palaeontology ranged over a
wide field. We find him at one time immersed in all
lu Sur les Ardoisieres d'Angers," Tram. Acad. Roy. Sciences, 1762,
p. 52. The Dudley trilobite of the Upper Silurian limestone ot
England had been figured and described by Lhuyd in his Lithophylacii
Britannici Iconographia (1699), Epist. i. p. 96 and PI. xxii. ; a figure
of it was subsequently given in Phil. Trans. 1754, PL x i- Fig. 2.
1 1 8 Guettard
the details of fossil sponges and corals. At another,
he is busy with the mollusca of the Secondary and
Tertiary rocks. Fossil fishes, carnivora, pachyderms,
cetacea all interest him, and find in him an enthusi-
astic and faithful chronicler. His descriptions are
not of the minutely systematic and technical order
which has prevailed since the time of Linnaeus. Yet
some of his generic names have passed into the
language of modern palaeontology, and one of the
genera of Chalk sponges which he described has been
named after him, Guettardia. He had within him the
spirit of the true naturalist, more intent on under-
standing the nature and affinities of organic forms
than on adding new names to the scientific vocabulary.
His descriptions and excellent drawings entitle him to
rank as the first great leader of the palaeontological
school of France.
As far back as the year 1751, when he was thirty-
six years old, he presented to the Academy a memoir
on certain little-known fossil bodies, in which he
struck, as it were, the keynote of his future life in
regard to the organic remains enclosed within the
stony records of former ages. Like a man entering
a vast charnel-house, he sees on every side proofs of
dead organisms. Others had observed these proofs
before him, and had recognized their meaning, and
he alludes to the labours of his predecessors. He
especially singles out Palissy, who, as already remarked,
was the first in France, some two hundred years
before, to embrace fossil shells in his view of Nature,
to maintain that they are the productions of the sea,
not of the earth, as had been supposed, and to demon-
His remarkable essay on Fossil Shells 1 1 9
strate from them that France once lay beneath the
sea, which had left behind it such vast quantities of
the remains of the creatures that peopled its waters.
In Normandy, whence many of Guettard's early
collections came, and where the people of the country
looked upon certain fossil bodies as forms of fruit
pears and apples that had fallen from the trees and
taken a solid form within the earth he tells how
half-witted he seemed to them when he expressed a
doubt regarding what they believed to be an obvious
truth. He recognised the animal nature of the or-
ganisms, and asserted that the so-called peaches, apples
and pears all belonged to the class of corals, though
many of them are now known to be sponges.
Of all his numerous and voluminous essays on palae-
ontological subjects, perhaps that which most signally
displays Guettard's modern and philosophical habit of
mind in dealing with fossil organisms is a long paper
in three parts, which appeared in 1765 under the title,
" On the Accidents that have befallen Fassil Shells
compared with those which are found to happen to
Shells now living in the Sea." * The controversy
about " figured stones " had not yet died out, and
there were still not a few observers who continued
to believe that the apparent shells found in the rocks
of the land never really belonged to living creatures,
but were parts of the original structure of the earth.
It is difficult, perhaps, to imagine ourselves in the
position of naturalists who even as late as the middle
of the eighteenth century, could still honestly persuade
themselves that the organic remains of fossiliferous
1 Trans. A cad. Roy. Sciences (1765), pp. 189, 329, 399.
1 20 Guettard
formations are entirely deceptive and never formed
part of living plants or animals. Yet unless we make
the effort to realise the attitude of men's minds in
those days, we cannot rightly appreciate the acumen
and sagacity of the arguments with which Guettard
assailed these opinions. In much detail, and with
many admirable illustrations drawn from his personal
observations all over France, he demonstrated that
fossil shells often have attached to them other shells,
and likewise barnacles and serpulae ; that many of
them have been bored into by other organisms, and
that in innumerable instances they are found in a frag-
mentary and worn condition. In all these respects
the beds of fossil shells on the land are shown to
present the closest possible analogy to the floor of the
present sea, so that it becomes impossible to doubt that
the accidents which have affected the fossil organisms
arose from precisely the same causes as those of exactly
the same nature that still befall their successors on the
existing ocean bottom.
Of course nowadays such reasoning appears to us
so obvious as to involve no great credit to the writer
who elaborated it. But we must remember the state
of natural knowledge one hundred and forty years
ago. As an example of the method of explaining
and illustrating the former condition of the earth's
surface by what can be seen to happen now, Guettard's
memoir is unquestionably one of the most illustrious
in the literature of geology, opening up, as it did, a
new field in the investigation of the history of our
globe, and unfolding the method by which this field
must be cultivated.
His Phy Biographical Geology 121
On what is now known as Physiographical Geology,
or the discussion of the existing topography of the
land, this same illustrious Frenchman left the impress
of his mind. I will cite only one of his contributions
to this subject a memoir c ' On the Degradation of
Mountains effected in our Time by heavy Rains,
Rivers and the Sea." 1 This work, which occupies
about 200 quarto pages, deals with the efficacy of
moving water in altering the face of the land. At
the very beginning of it, he starts with a reminiscence
from the scenes of his infancy, and weaves it into the
story he has to tell of the ceaseless degradation of
the terrestrial surface. He remembers a picturesque
crag of the Fontainebleau sandstone which, perched
above the slopes of a little valley, had been worn
by the weather into a rudely-formed female figure
holding an infant, and had been named by the peasantry
the Rock of the Good Virgin. That crag, under
which he used to play with his schoolmates, had in
the interval of less than half a century gradually
crumbled away, and had been washed down to the
foot of the declivity. In the same neighbourhood he
had noticed at successive visits that prominent rocks
had made their appearance which were not previously
visible. They seemed, as it were, to start out of
the ground, yet he knew that they arose simply from
the removal of the material that once covered them.
In like manner, ravines of some depth were in the
course of a few years cut out of ground where
there had before been no trace of them. In these
1 See vol. iii. of his Memoires sur differentes parties des Sciences et
des Arts, pp. 209-4.03.
122 Guettard
striking examples of the general disintegration, he sees
only the continual operation of " gentle rains and
heavy downpours." 1
From illustrations supplied by his own earliest ob-
servation, he passes on to others drawn either from
his personal researches or his reading, and exemplify-
ing the potent influence of heavy rains and flooded
streams. Not only are the solid rocks mouldering
down and strewing the slopes below with their debris,
but the sides of the hills are gashed by torrents, and
narrow defiles are cut in them, like the Devil's Gap
in Normandy. 2 He combats the notion that land-
slips, such as had occurred at Issoire in Auvergne
in the year 1733, were caused by internal fires or
subterranean winds, and agrees with a previous writer
in regarding them as the result of the penetration
of water from the surface into the interior of the
hill. He thus recognises the efficacy of subterranean
as well as superficial water, in changing the face of a
country.
He believes the sea to be the most potent destroyer
of the land, and as an instance of its power he was
accustomed to regard the chalk cliffs of the north-
west of France as the relics of a great chain of hills,
of which the greater part had been swept away by
the sea. 3 He shows, further, that while the hills are
worn down by the waves, by the rains, and by the
inundations to which the rains give rise, the materials
removed from them are not destroyed, but are de-
posited either on the land or along the shores of the
1 " Des pluies et des averses," Op. cit. p. 210.
2 P. 214. 8 Pp. 22O, 222.
On the river-basins of France 123
sea. 1 He further points out that the detritus of sepa-
rate river-basins may greatly differ, and that materials
may be carried into districts where the rocks are
entirely distinct from those in the areas whence the
transport has taken place. He refers to the practical
value of this observation in questions regarding the
source of minerals, ores and useful stones. 2
He is thus led to give, from his wide knowledge
of France, a sketch of the character of the rocks in
the different river-basins of the country, and the
nature of the materials which the rivers have in each
case to transport. He passes in review all the large
streams that enter the Atlantic from the Rhine to
the shores of Gascony, and considers, likewise, the
Rhone with its tributaries on the Mediterranean side
of the watershed. 3 He infers that all the debris
derived from the waste of the land is not carried to
the sea, but that a great deal of it is deposited along
the borders of the streams, and that though it may
be removed thence, this removal must require many
ages to accomplish. He thinks that the levels of
the valleys are at present being raised owing to the
deposit of detritus in them. 4 The plains watered by
the rivers are one vast sheet of gravel, the streams
having changed their courses again and again, so as
to flow in turn over every part of these alluvial
tracts. The thickness of detritus brought down by
the rivers gradually increases towards their mouths.
Near their sources, on the other hand, any sediment
which is deposited is in a manner superficial, and is
1 P. 222. 2 P. 223.
3 p. 225-324. 4 P. 326.
1 24 Guettard
liable to continued removal and transportation farther
down.
The fragmentary material that is accumulated along
the margin of the sea is, in Guettard's view, derived
either from what is borne down by rivers, or from
what is made by the sea itself, the whole being ground
into powder by the long-continued beating of the
waves. The sea not only acts on its shores, but on
submerged rocks, and the detritus thus produced is
mingled with the triturated remains of corals, shells,
fish-bones and marine plants. 1
Comparatively little information had been gathered
in Guettard's time as to the condition of the sea-
bottom. There is thus a peculiar interest in noting
the ideas which he expresses on this subject. He
thinks that, besides what is laid down upon the
shore, another portion of the detritus is borne away
seawards, and gradually settles down on the sea-floor.
As the nature of the part so transported must depend
on that of the material on the shore, he is led to
enter upon a minute examination of the mineral
constitution of the coast- lines of France, both on
the Atlantic and Mediterranean margins of the
country. 2
He recognises that soluble substances may be carried
for great distances from the land, and may remain
dissolved in the sea-water for a very long time. He
even conjectures that it is possibly these substances
that impart its salinity to sea-water. 3
FYom all the soundings available in his day, he
concludes that the bottom of the sea is, throughout
!P. 328. 2 P. 328. 3 P. 3 60.
His conception of the sea-floor 125
its whole extent, covered mostly with sand, which is
probably not derived from the detritus of rivers. 1 He
observes, regarding this widely-diffused deposit, that
it might be thought to be due to the grinding down
of submarine rocks by the sea itself. But he con-
tends that " how violent soever may be the movements
of the sea, they can have but little effect, save on
those rocks which emerge above the level of the
water, the greatest storms being little felt except on
the surface, and for a short way below it." In this
sagacious and generally accurate inference, however,
he was long before anticipated by Boyle.
Considering, further, the problem presented by the
general diffusion of sand over the bed of the sea, he
thinks that the erosive influence of the ocean cannot
be enough to account for this deposit, which is spread
over so vast an area. He concludes, therefore, that
the sand must date back to the remote ages of the
destruction of the mountains. The submarine rocks
met with in sounding are, he thinks, unquestionably
the remains of mountains formerly destroyed, and the
detached boulders similarly discovered are no doubt
the result of the destruction of these rocks, though
in some cases they may have been derived from
neighbouring islands where such exist. 2
No argument against this view of the high antiquity
of the sandy sediment on the sea-floor can, he believes,
be drawn from the presence of shells, either singly or in
numbers, in this sand. These he regards as obviously
the relics of molluscs of the present time, those of
former ages having been long ago destroyed. 3
*P. 401. 2 Pp. 401, 402. 3 P. 4 02 -
126 Guettard
He remarks, in conclusion, that " it follows, from
all the observations here recited, that the deposits
laid down by the sea along its shores are sandy and
loamy ; that these deposits do not extend far out
to sea ; that, consequently, the elevation of new
mountains in the sea by the deposition of sediment is
a process very difficult to conceive ; that the transport
of the sediment as far as the equator is not less
improbable ; and that still more difficult to accept is
the suggestion that the sediment from our continent
is carried into the seas of the New World. In short,
we are still very little advanced towards the theory
of the earth as it now exists. All the systems which
have been devised in this subject are full of difficulties
which appear to me to be insoluble." He proposes,
finally, to return, should the occasion present itself,
to these questions, which are " all the more interesting
the more difficult they are to elucidate." J
It cannot be claimed that such enlightened views
regarding the subaerial degradation of the land were
now for the first time proclaimed to the world.
Guettard had been to some extent preceded by other
writers. Thus the English naturalist Ray, some
ninety years before, had pointed out how in course
of time the whole dry land might be washed into
the sea (ante, p. 74). Generelli, too, in his defence
of Lazzaro Moro, twenty years before the appearance
of Guettard's volume, had dwelt on the evidence of
the constant degradation of the mountains by running
water, as an argument for the existence of some other
natural cause, whereby, from time to time, land was
ipp. 402, 403.
His Volcanic Discovery 127
upraised to compensate for the universal waste. It
must be admitted, however, that no one had elabo-
rated the subject so fully until it was taken up by the
French observer, and that he was the first to discuss
the whole phenomena of denudation, apart altogether
from theory, as a great domain for accurate and pro-
longed observation.
I have reserved for mention in the last place the
discovery for which chiefly Guettard's name has
received such mention as has been accorded to it in
English scientific literature. He was the first to
ascertain the existence of a group of old volcanoes
in the heart of France. This contribution to the
geology of the time may seem in itself of compara-
tively small moment, but it proved to be another
important onward step made by the same indefatigable
and clear-sighted naturalist, and laid the foundations
of another department of the natural history of the
earth. It became also the starting-point of one of
the great scientific controversies of the latter half
of the eighteenth and the first decades of the
nineteenth century. There is thus a peculiar interest
in watching how the discovery was made and worked
out by the original observer.
The story goes back to the early months of 1752,
for on the loth of May of that year Guettard read
to the Academy a " Memoir on Certain Mountains
in France which have once been Volcanoes." He
tells how he had undertaken further journeys for
the purpose of obtaining additional information towards
the correction and amplification of his map of France,
l Mem. Acad. Roy. Sciences, vol. for 1756, p. 27.
128 Guettard
showing the distribution of his "bands" with their
characteristic minerals. He was accompanied by his
former schoolfellow and then his valued friend, Male-
sherbes. On reaching Moulins on the Allier, he was
struck by the nature of the black stone employed
for mile-posts, and felt certain that it must be of
volcanic origin. On inquiring whence the material
came, and learning that it was from Volvic, " Volvic ! "
he exclaimed, " Volcani Vicus ! " and at once deter-
mined to make without delay for this probably volcanic
centre. 1 His excitement in the chase after an unknown
volcano seems to have increased with every step of
the journey, as more and more of the dark stone
appeared in the buildings by the roadside. At Riom
he found the town almost entirely built of the material,
which he felt sure he had now run nearly to earth.
Learning that the quarries were still some two leagues
distant, he pushed on to them, and great was his
delight to find all his suspicions amply confirmed.
He recognised the rock as a solidified current of lava
which had flowed down from the high granitic ridge
for some five miles into the plain below, and he found
1 Twenty-eight years after this discovery Guettard found himself
forced to defend his claim to be the discoverer of the old volcanoes
of Central France, and to ask his friend Malesherbes for his testi-
mony to the justice of that claim. Malesherbes accordingly wrote
him a letter giving an account of their journey to Auvergne, which
Guettard printed in the preface to his treatise, in two volumes, on
the mineralogy of Dauphine. It is curious that, with the statements
of the two travellers long before in print, Scrope should have
published a totally inaccurate version of the journey in the first
edition of his Volcanoes of Central France, and should have repeated
it in the second edition.
Among the Auvergne Volcanoes 129
the actual cone and crater from which the molten
flood had issued.
We can follow the enthusiastic explorer with warm
sympathy as he eagerly and joyously sees at each
onward step some fresh evidence of the true volcanic
nature of the rocks around him. Though he had
never beheld a volcano, he was familiar with their
outlines, from the available engravings of the time.
Ascending a hill beyond the quarries, he perceives its
conical form to be that of a typical volcano. 1 As he
climbs the rough slopes, he identifies the crumbling
debris of black and red pumice, together with the
blocks of rugged spongy slags and scoriae, as mani-
festly the products of a once active volcanic vent.
When he reached the truncated summit of the hill,
what must have been his delight to behold below
him the smooth-sloped hollow of the crater, not now
belching forth hot vapours and ashes, but silent and
carpeted with grass ! For centuries the shepherds had
pastured their flocks on these slopes, and the quarry-
men had been busy cutting and sending off the lava
for roads and buildings, but no one had ever suspected
that this quiet and lonely spot retained such striking
monuments of subterranean commotion.
Descending to the great lava-stream, Guettard scruti-
nized its structure as laid open in the quarries, and at
once noticed how different in character it was from any
other rock he had ever seen in France. He observed
1 Desmarest affirms that it was not the Puy de la Nugere, the
source of the Volvic lava, which Guettard ascended, but the Puy
de la Banniere, and that the former hill was unknown to him.
Encyclopedic Methodique, Geographic Physique, vol. i. p. 187.
130 Guettard
it to be divided into sheets inclined with the general
slope of the ground, but separated from each other
by layers of clay, earth or sand, as in the case of sedi-
mentary formations, yet solid, and breaking easily in
any direction, so as to lend itself readily to the arts
of the stone-mason.
Travelling southward along the base of the pic-
turesque ridge of the Puys, Guettard and Malesherbes
reached Clermont, where they procured the services
of an intelligent apothecary, who had some knowledge
of the topography of the hills. They climbed the
steep slopes of the Puy de Dome a hill made famous
by Pascal. Everywhere they noticed volcanic debris
partially concealed under vegetation. If the view from
the first volcano above Volvic delighted the travellers,
we can imagine their amazement and pleasure when
the marvellous panorama around the highest craterless
summit spread itself like a map around them. As
their eyes ranged over that array of old volcanoes, so
perfect in form that it is difficult to believe them to
have been silent ever since the beginning of human
history, they could mark the cones rising one behind
the other in long procession on the granite ridge,
each bearing its cup-shaped crater atop.
In descending from the mountain they came upon
another crater, probably that of the Petit Puy de
Dome, a singularly perfect example of the type, some
300 feet deep, and the same in diameter of rim, with
such regular and smooth slopes that it has been named
by the shepherds the Hen's Nest. Everywhere they
encountered quantities of pumice, which so entirely
convinced Guettard of the true volcanic nature of the
His Volcanic Memoir 131
district, that he found it unnecessary for his immediate
purpose to examine the rest of the puys. Their Cler-
mont guide, though he had previously wandered over
the hills, had never suspected their volcanic origin ;
but he seems to have learnt his lesson promptly, for
he soon afterwards, at Guettard's request, sent some
details, and wrote about eruptions and explosions as
if he had been long familiar with their effects.
Not only did Guettard detect some sixteen or seven-
teen cones, but he observed that their craters looked
in different directions, and he thought that they pro-
bably belonged to different periods of eruption. The
travellers pushed on to the great volcanic centre of
Mont Dore. But Guettard was there less successful.
He was unaware of the influence of long-continued
denudation in altering the external forms of volcanic
hills, and was disposed to regard his ill success as
probably due to the mantle of vegetation by which
so much of the ground was concealed.
The journey in Auvergne was too brief and hurried
to admit of any single point being fully worked out.
But Guettard believed that he had amassed material
enough to prove the main question which interested
him that there had formerly been a series of active
volcanoes in the heart of France. So he prepared
an account of his observations, and read it to the
Academy of Sciences on loth May, 1752.
This early memoir on the extinct volcanoes of
Europe must not be tried by the standard which has
now been attained in the elucidation of volcanic rocks
and the phenomena of ancient eruptions. We should
be unjust if we judged it by the fuller knowledge
132 Guettard
obtained of the same region of France by the more
detailed examination of other observers even in Guet-
tard's lifetime. Desmarest, whose splendid achieve-
ments will be referred to in the next chapter, was
conspicuously guilty of this injustice. He would never
allow Guettard credit for his work in Auvergne, find-
ing fault with it because it was imperfect and inaccurate.
He wished that, before writing on the subject at all,
his predecessor had studied the ground more carefully
and in greater detail, and had attended to the different
conditions and dates of the eruptions. " Can we
regard as a true discovery,'' he asks, " the simple
recognition of the products of volcanic action, when
the facts are presented with so little order and so
much confusion ? Such a discovery implies a reasoned
analysis of all the operations of fire, of which the
results have been studied, so as to reveal the ancient
conditions of all the volcanic regions. Without this
it is impossible to dignify the recognition of a few
stones with the name of a discovery that will advance
the progress of the natural history of the earth." l
Could any judgment be more unfair ? As if no
discovery is entitled to the name, unless it has
been elaborated in the fullest detail and followed to
its remotest consequences ! When one of Guettard's
countrymen and contemporaries could write thus of
his claims to recognition, it is not surprising that for
the best part of a century his name should have
almost entirely passed out of mind.
That Guettard preceded every one else in the
recognition of the old volcanoes of Auvergne, and
1 Geographic Physique, Art. " Guettard."
His mews of Volcanic Action 133
that he thus became the originator of the Vulcanist
party in the famous warfare at the end of last century,
in no way diminishes the claim of Desmarest to occupy
the foremost place among the Vulcanists, and to be
ranked as the real founder of volcanic geology. I shall
have occasion to dwell at some length on Desmarest's
work, which for accuracy and breadth has never been
surpassed.
Guettard, having never seen a volcano, was guided
in his observations and inferences by what he had read
of volcanic countries, and what he had learnt about
lavas by familiarity with specimens of these rocks
brought from Vesuvius and other modern volcanoes.
He noted the close resemblance between the rocks
of Auvergne and the Italian lavas, not only in appear-
ance, density and other characters, but in their position
on the ground, the specimens which he had gathered
from the bottom, sides and crests of the puys having
each their own distinctive peculiarities, as in existing
volcanoes. He compared the curved lines on some of
the rocks of Mont Dore and the Puy de Dome with
the ropy crusts of certain Vesuvian lavas.
When this distinguished man stepped from the
observation of fact into the region of theory, he at
once fell into error, but the error was one which, as
we have seen, had passed current as obvious truth
for more than 2000 years. " For the production of
volcanoes/' he remarks, " it is enough that there
should be within these mountains substances that can
burn, such as petroleum, coal or bitumen, and that
from some cause these materials should take fire.
Thereupon the mountain will become a furnace, and
1 34 Guettard
the fire, raging furiously within, will be able to melt
and vitrify the most intractable substances/' l He finds
evidence in Auvergne of this presumed connection
between the combustion of carbonaceous substances
and volcanic eruptions, and he cites in illustration the
Puy de Crouel and Puy de la Poix, near Clermont,
where the black bituminous material can actually be
seen at the surface. Summing up his observations he
concludes thus : " I do not believe that the reality
of our volcanoes will now be called in question, save
perhaps from anxiety for the safety of the districts
around them. For myself, confident as to the first
point, I confess that I share in the anxiety regarding
the second. Hot springs have generally been regarded
as due to some kind of concealed volcanoes. Those
of Mont Dore rise at the very foot of the mountains ;
those of Clermont are only some two leagues from
the chain of the Puys. It may very well be that their
high temperature is kept up by the same internal fires
which formerly had a communication with these extinct
volcanoes, or might now easily establish one should
they increase in activity." 2
His fears for the safety of the Auvernois were by
no means shared by the people themselves, for they
refused to believe that the Puys, which they had
known from infancy as quiet, well-behaved hills, had
ever been anything else, and they looked upon the
1 Trans. Roy. Acad. Sciences for 1756, p. 52. This adoption of the
time-honoured belief is severely criticised by Desmarest, but the same
belief was subsequently accepted by Werner, and became a prominent
item in the Wernerian creed.
2 0/. cit. p. 53.
On origin of Basalt 135
learned doctor's descriptions of the former eruptions
as mere speculation of his own manufacture.
In taking leave of Guettard's scientific labours, I
must refer to one further essay of his, on account of
its connection with his work among the old volcanoes
of Auvergne. Eighteen years after his memoir on
these hills had been read to the Academy, he published
a paper " On the Basalt of the Ancients and the
Moderns." 1 The furious war over the origin of
basalt, of which I shall give some account in a later
chapter, had not yet definitely begun. Various writers
had maintained that this rock is of volcanic origin, and
we might have supposed that Guettard's experience in
Auvergne would have led him to adopt this correct
opinion. So far from doing so, however, he entered
into an elaborate discussion to show that basalt could
not be a volcanic rock. He admitted that it is found
among volcanic masses, but he accounted for its pre-
sence there by supposing that in some cases it was
already in that position before the eruptions, in others
that it had been laid down upon the lavas after they
had consolidated. c< If a columnar basalt can be pro-
duced by a volcano," he asks, " why do we not find
it among the recent eruptions of Vesuvius and other
active volcanoes ? " After reviewing all that had then
been written on the subject, he concludes that " basalt
is a species of verifiable rock, formed by crystallization
in an aqueous fluid, and that there is no reason to
regard it as due to igneous fusion." 2
1 Memoir es sur dijferentes parties des Sciences et des Arts, tome ii.
p. 226 (1770).
2 O/. fit. p. 268.
136 Guettard
We may gather how little was then known of the
characters of modern lavas when Guettard was ignorant
of the occurrence of columnar structure among them. 1
He was as hopelessly wrong in regard to the origin
of basalt, as he was with respect to the nature of
volcanic action. How this error originated will
appear in an examination of the controversy to
which basalt gave rise. But the most interesting
feature in the passage just cited from Guettard is
not his mistake about basalt, but his clear enuncia-
tion of his belief in its deposition from aqueous
solution, for he thus forestalled Werner in one of
the most keenly disputed parts of his geognosy.
I know nothing more whimsical in the history of
geology than that the same man should be the parent
of two diametrically opposite schools. Guettard's
observations in Auvergne practically started the Vul-
canist camp, and his promulgated tenets regarding
basalt became one of the watchwords of the Neptunists.
The notable Frenchman, of whose work I have
now attempted to give an outline, must have been
a singular figure as he moved about among his con-
temporaries. Endowed with a healthy constitution, he
had strengthened it by travel, and by a hard and sober
life. At last he became liable to attacks of a heavy
lethargic sleep, during one of which his foot was
burnt. The long and painful healing of the wound
he bore with stoical patience, though often convinced
of the uselessness of the remedies applied. " I see
1 We shall find that this ignorance continued for many years
after Guettard's time, and was characteristic of the Wernerian
school.
His Character 137
quite well," he would say, " that they want to ward
off the stroke ; but they will not succeed." The
idea of the kind of death that would terminate his
life never left his mind, but did not in the least affect
his cheerfulness. He continued to come assiduously
to the meetings of the Academy of Sciences alone
and on foot, taking only the precaution to carry in
his pocket his full address, that in case of anything
happening to him, he might be taken home. By
degrees he declined to dine with his friends, and then
went seldom to see them, quietly assigning as his
excuse the fear of troubling them with the sight of
his death. He passed away at last on the yth of
January 1786 at the age of seventy-one years.
The kindly eloge of Condorcet enables us to form
some idea of the character and peculiarities of the
man. From his childhood onwards he was eminently
religious. His nature was thoroughly frank and
honest, simple and unambitious. Scrupulously exact
in his own dealings with fact, he hated everything
savouring in the least of insincerity and subterfuge.
His transparent sincerity gained him friends every-
where ; yet he was readily irritated, and had a certain
brusqueness of manner, which perhaps detracted from
the charm of his character and led to his being some-
times much misunderstood. One of his acquaintances
once thanked him for having given a vote in his
favour. " You owe me nothing for that," was
Guettard's abrupt reply. " If I had not believed
that it was right to give it to you, you should not
have had it ; for I don't like you." Condorcet tells
how, when they met at the Academy on the occasion
138 Guettard
of the delivery of the customary ttoges of deceased
members, Guettard, who looked on all these things
as unveracious statements, would say to the perpetual
Secretary, " You are going to tell a lot of lies. When
it comes to my turn I want only the truth told about
me." Condorcet, in sketching the defects as well as
the excellences of his friend's character, remarks that
in fulfilling his wishes in the strictest sense, he is
rendering to Guettard the homage that he himself
would most have desired. So little did he try to
seem better than he was, that his defects might be
most prominent to those who merely casually met
him, while his sterling qualities were known only to his
friends. u Those who knew Guettard merely by some
brusque answer or other indication of bad temper,"
his biographer remarks, c< would be surprised to learn
that this man, so severe in appearance, so hard to
please, forced by the circumstances of his position
to live alone, had actually adopted the large family
of a woman who had been his servant, brought up
the children and watched over the smallest details of
their education ; that he could never see any one in
distress without not only coming to his help, but
even weeping with him. He bore the same sensibility
towards animals also, and expressly forbade that any
living creature should be killed for him or at his
house. He was a man who, losing control of his
words when in bad humour, had quarrelled more than
once with each of his friends, yet had always ended
by loving them and being loved more than ever by
them ; who had hurt most of his associates in his
disputes with them, but yet had preserved the friend-
His position in History of Science 139
ship of several of them, and had never diminished
in any one of them the esteem which it was impossible
to refuse to his character and his virtues." l
Guettard's position in the history of science is that of
an indefatigable and accurate observer who, gifted with
a keen eye, well-trained powers of investigation, and
much originality of mind, opened up new paths in a
number of fields which have since been fruitfully
cultivated, but who rigidly abstained from theory or
speculation. In geology, he deserves to be specially
remembered as the first to construct, however imper-
fectly, geological maps, the first to make known the
existence of extinct volcanoes in Central France, and
one of the first to see the value of organic remains
as geological monuments, and to prepare detailed
descriptions and figures of them. To him also are
due some of the earliest luminous suggestions on the
denudation of the land by the atmospheric and marine
agents. " By his minute and laborious researches he
did more to advance the true theory of the earth
(on which, however, he never allowed himself to
hazard a single conjecture) than the philosophers who
have racked their brains to devise those brilliant hypo-
theses, the phantoms of a moment, which the light of
truth soon remands into eternal oblivion." 2
1 Condorcet's Eloge, pp. 238, 240. 2 Condorcet, op. cit.
CHAPTER V
THE Foundation of Volcanic Geology. Desmarest.
THE leading position acquired by France in the
investigation of the history of the earth, through the
labours of such men as Descartes, Buffon and Guettard,
was well maintained in the later decades of the
eighteenth century. Geology indeed as a distinct
science did not yet exist. The study of rocks and
their contents was known as mineralogy, which as a
pursuit, often of economic value, had been in vogue
for centuries. The idea that beyond the mere variety
of its mineral contents, the crust of the earth con-
tained a record of the earth's evolution, for many
ages before the advent of man, only very slowly took
definite shape. Buffon partly realized it ; Guettard
had a fuller perception of its nature, though he failed
to observe proofs of a long succession of changes
earlier than the present condition of the surface.
One of the most valuable parts of Guettard's work
was his recognition of the existence of volcanic rocks
in regions far removed from any active volcano. We
have seen that he was led to this important deduction
by a train of observation and inference, and that
although he never worked out the subject in detail,
Nicholas Desmarest 141
the credit of the first discovery, denied to him in his
lifetime and after it, must in common fairness be
assigned to him.
Central France was the region that furnished
Guettard with his proofs of extinct volcanoes. It was
the same region that afterwards supplied fuel to the
controversy over the origin of basalt which raged
with fury for so many years, and it was from this
region also that the proofs were obtained which more
than any others brought that controversy to an end.
The story of this old battle is full of interest and
instruction. We learn from it how the advance of
truth may be impeded by personal authority ; how,
under guise of the most rigorous induction from fact,
the most perverse theories may be supported ; how,
under the influence of theoretical preconceptions, the
obvious meaning and relations of phenomena may
be lost sight of, and how, even in the realm of
science, dry questions of interpretation may become
the source of cruel misrepresentation and personal
animosity.
To understand the history of this controversy, we
must trace the career of another illustrious French-
man who, with less opportunity for scientific work
than Guettard, less ample qualifications in all depart-
ments of natural science, and less promptitude in
putting the results of his observations into tangible
form, has nevertheless gained for himself an honoured
place among the founders of modern geology.
Nicholas Desmarest (1725-1815) was born in humble
circumstances at Soulaines, a little town in France
between Bar-sur-Aube and Brienne, on i6th September
142 Desmarest
1725.* He was thus exactly ten years younger than
Guettard. So pinched were the conditions of his
youth that he could hardly read even when fifteen
years old. From that time, on the death of his
father, better prospects dawned upon him. The parish
priest urged his guardian to have him educated, as
far as the slender means left for his sustenance would
allow. He was accordingly sent to the college of
the Oratorians of Troyes ; but the pittance available
for his benefit was exhausted by the first few terms
of his stay there. He had, however, made such
marked progress that his teachers, interested in his
career, were glad to continue gratuitously the instruc-
tion for which he could no longer pay. At the end
of his time with them, they passed him on to their
brethren in Paris.
Having made some advance, especially in geometry
and physics, he was able to support himself by private
teaching and other labours which, however, barely
provided the necessaries of life. After some ten years
of this drudgery, the studies which had been his
occupation and solace, came at last to be the means
of opening up a new and noble career to him.
The appearance of BufFon's Theory of the Earth^ in
1749, had had a powerful influence in France in
directing attention to the revolutions through which
our globe has passed. Among the results of this
influence, a society which had been founded at Amiens
by the Due de Chaulnes, proposed in 1752 a prize
1 The biographical details of the following sketch are taken from the
well-known eloquent Eloge of Desmarest by Cuvier, Recuei( des Eloges
Historiques, edit. 1819, vol. ii. p. 339.
His first geological Essay 143
for an essay on the question whether England and
France had ever been joined together. The subject
caught Desmarest's fancy, he made some investiga-
tions, sent in an essay and carried off the prize.
Cuvier, in his E/oge, remarks on the strong con-
trast between the way in which Desmarest approached
his task and that in which BufFon, who had aroused
public attention to these subjects, was accustomed to
deal with them. The young aspirant to fame, then
twenty-eight years of age, allowed himself no hypo-
thesis or theory. He would not travel beyond the
positive facts and the inferences that might be
legitimately deduced from them. Dealing with the
correspondence between the material forming the
opposite cliffs of the two countries (which had already
been pointed out by Guettard), and with the form
of the bottom of the shallow strait, he passed on to
consider the former prevalence in England of many
noxious wild animals, which could not have swum
across the sea, and which man would certainly have
taken care not to introduce. From a review of all
the considerations which the subject presented, he
drew the inference that a neck of land must once
have connected England and France, and that this
isthmus was eventually cut through by the strong
currents of the North Sea.
This essay, so different in tone from the imaginative
discourses of Buffon, attracted the attention of D'Alem-
bert, and led him to seek the acquaintance of its
author. The friendship of this great man was itself
a fortune, for it meant an introduction into the most
learned, intelligent, and influential society of the day.
144 Desmarest
Desmarest was soon actively employed in tasks for
which his knowledge and capacity were found to fit
him, and thenceforth his struggle with poverty came
to an end. Among those who befriended him, the
young Due de la Rochefoucault was especially help-
ful, taking him on his travels and enabling him to
see much of France and Italy.
Shortly after the middle of the eighteenth century,
the Governments of Europe, weaned with ruinous
and profitless wars, began to turn their attention
towards the improvement of the industries of their
peoples. The French Government especially distin-
guished itself for the enlightened views which it took
in this new line of national activity. It sought to
spread throughout the kingdom a knowledge of the
best processes of manufacture, and to introduce what-
ever was found to be superior in the methods of
foreign countries. Desmarest was employed on this
mission from 1757 onwards. At one time he would
be sent to investigate the cloth-making processes of
the country : at another to study the various methods
adopted in different districts in the manufacture of
cheese. Besides being deputed to examine into the
condition of the industries of different provinces of
France, he undertook two journeys to Holland to
study the paper-making system of that country. He
prepared elaborate reports of the results of his investi-
gations, which were published in the Memoires of
the Academic des Sciences, or in the Encyclopedic
Methodique. At last in 1788 he was named by the
King Inspector-General and Director of the Manu-
factures of France.
Director of Manufactures 145
He continued to hold this office until the time of
the Revolution, when his political friends Trudaine,
Malesherbes, La Rochefoucault, and others perished
on the scaffold or by the knife of the assassin. He
himself was thrown into prison, and only by a
miracle escaped the slaughter of the 2nd September.
After the troubles were over, he was once more
called to assist the Government of the day with his
experience and judgment in all matters connected
with the industrial development of the country. It
may be said of Desmarest that " for three quarters
of a century it was under his eyes, and very often
under his influence, that French industry attained
so great a development."
Such was his main business in life, and the manner
in which he performed it would of itself entitle him
to the grateful recollection of his fellow-countrymen.
But these occupations did not wholly engross his
time or his thoughts. Having early imbibed a taste
for scientific investigation, he continued to interest
himself in questions that afforded him occupation
and solace, even when his fortunes were at the lowest
ebb.
" Resuming the rustic habits of his boyhood,"
says his biographer, " he made his journeys on foot,
with a little cheese as all his sustenance. No path
seemed impracticable to him, no rock inaccessible.
He never sought the country mansions, he did not
even halt at the inns. To pass the night on the
hard ground in some herdsman's hut, was to him
only an amusement. He would talk with quarry-
men and miners, with blacksmiths and masons, more
K
146 Desmarest
readily than with men of science. It was thus that
he gained that detailed personal acquaintance with
the surface of France with which he enriched his
writings."
During these journeyings, he was led into Auvergne
in the year 1763, where, eleven years after Guettard's
description had been presented to the Academy, he
found himself in the same tract of Central France,
wandering over the same lava-fields, from Volvic to
the heights of Mont Dore. Among the many puzzles
reported by the mineralogists of his day, none seems
to have excited his interest more than that presented
by the black columnar stone which was found in
various parts of Europe, and for which Agricola,
writing in the middle of the sixteenth century, had
revived Pliny's old name of " basalt." The wonder-
ful symmetry, combined with the infinite variety of
the pillars, the vast size to which they reached, the
colossal cliffs along which they were ranged in
admirable regularity, had vividly aroused the curiosity
of those who concerned themselves with the nature
and origin of minerals and rocks. Desmarest had
read all that he could find about this mysterious
stone. He cast longing eyes towards the foreign
countries where it was developed. In particular, he
pictured to himself the marvels of the Giant's Cause-
way of the north of Ireland, as one of the most
remarkable natural monuments of the world, where
Nature had traced her operations with a bold hand,
but had left the explanation of them still concealed
from mortal ken. How fain would he have directed
his steps to that distant shore. Little did he dream
Distribution of Basalt in Europe 1 47
that the solution of the problems presented by basalt
was not to be sought in Ireland, but in the heart
of his own country, and that it was reserved for
him to find.
Before referring to the steps in Desmarest's progress
towards the discovery of the origin of basalt, let me
briefly sketch what was known on the subject at
the time when he began his researches. Agricola
had mentioned that this dark prismatic stone was to
be seen in different parts of Germany, and in particular
that it formed the eminence on which the old castle
of* Stolpen in Saxony had been built. 1 It was after-
wards found to be abundantly distributed, not only
in Saxony, but in Silesia, in Cassel, and in the
valley of the Rhine above Cologne. 2 In these places
it is generally to be seen in detached eminences,
frequently capping hills, and presenting its vertical
columns in rows along its edges. There is nothing
about it which in those days was likely to suggest
a volcanic origin. The exposures of it in Germany
usually belong to an older geological period than the
comparatively recent lava-streams of Auvergne, and
in the course of time the cones and craters and
scoriae, that no doubt originally marked these sites,
have gradually disappeared.
The Giant's Causeway, too, though it displays on
a far more colossal scale the characteristic structure
and scenery of basalt, is equally silent in regard to
1 De Natura Fossi/tum, lib. vii. p. 315. Folio, Basel, 1546.
2 Various authors who had noticed the occurrence of basalt
before the publication of his memoir are cited by Desmarest.
Mem. Acad. Roy. Sciences, vol. for 1774, p. 726 et seq.
148 Desmarest
its origin. The marvels of this part of the coast
of Ireland had frequently been brought to the notice
of the learned, from the latter part of the seventeenth
century onward. 1 But here as elsewhere, it was rather
the symmetrical structure of the rock than the mode
of its formation that engaged the attention of the
older observers. Even as far back as the year 1756,
one of these writers pointed out the remarkable
resemblance of certain rocks in Nassau and in the
district of Treves and Cologne to the Giant's
Causeway, which by that time had become famous. 2
The Western Islands of Scotland, which far surpass
the Irish coast in the extent and magnificence of their
basalt cliffs, were still unknown to the scientific world.
The first report about their wonders seems to have
reached London in the spring of 1761, when the
Bishop of Ossory sent to the Royal Society a letter
he had received from E. Mendez da Costa telling
him that c< in Cana Island to the southward of
Skye and near the island of Rum the rocks rise
into polygon pillars . . . jointed exactly like those
of the Giant's Causeway." 3 But it was reserved for
Sir Joseph Banks to give the first detailed account
of the cliffs of Staffa and Fingal's Cave, which from
that time shared with the Giant's Causeway in the
!See Sir R. B., Phil Trans, xvii. (1693) p. 708; S. Foley,
xviii. (1694) p. 170, with a map and bird's-eye view. T. Moly-
neux, Ibid. p. 181 and xix. (1698) p. 209, with drawings of the
columns. R. Pocock, xlv. (1748) p. 124, and xlviii. part i. (1754),
with further figures illustrating the jointing of the columns.
2 A. Trembly, Phil. Tram. xlix. (1756) p. 581.
*Phll. Trans, lii. (1761) p. 163,
Theories as to origin of Basalt 1 49
renown that drew a yearly increasing number of
travellers to these distant shores. 1
Much had thus been learnt as to the diffusion of
basalt in Europe, and many excellent drawings had
been published of the remarkable prismatic structure
of this rock. But no serious attempt seems to have
been made to grapple with the problem of its origin.
Some absurd notions had indeed been entertained on
this subject. The long regular pillars of basalt, it
was gravely suggested, were jointed bamboos of a
former period, which had somehow been converted
into stone. The similarity of the prisms to those of
certain minerals led some mineralogists to regard
basalt as a kind of schorl, which had taken its
geometrical forms in the process of crystallization.
Rome de Lisle is even said to have maintained that
each basalt prism ought to have a pyramidal termina-
tion, like the schorls and other small crystals of the
same nature. 2
Guettard, as we have seen, drew a distinction
between basalt and lava, and this opinion was general
in his time. The basalts of Central and Western
Europe were usually found on hill tops, and dis-
played no cones or craters, or other familiar sign
of volcanic action. On the contrary, they were not
infrequently found to lie upon, and even to alternate
1 See Pennant's Tour in Scotland, 1772, where Banks' narrative
is inserted with a number of excellent engravings of the more
remarkable features in Staffa.
2 In the second edition of his Crystallographie (1783) he clearly
distinguishes between crystallization and basaltic structure. The
latter he regards as due to desiccation or cooling, tome i. p. 439.
150 Desmarest
with, undoubted sedimentary strata. They were,
therefore, not unnaturally grouped with these strata,
and the whole association of rocks was looked upon
as having had one common aqueous origin. It was
also a prevalent idea that a rock which had been
molten must retain obvious traces of that condition
in a glassy structure. There was no such con-
spicuous vitreous element in basalt, so that this
rock, it was assumed, could never have been vol-
canic. 1 As Desmarest afterwards contended, those
who made such objections could have but little
knowledge of volcanic products.
We may now proceed to trace how the patient
and sagacious Inspector of French industries made
his memorable contribution to geological theory. It
was while traversing a part of Auvergne in the year
1763 that he detected for the first time columnar
rocks in association with the remains of former
volcanoes. On the way from Clermont to the Puy
de Dome, climbing the steep slope that leads up to
the plateau of Prudelle, with its isolated outlier of a
lava-stream that flowed long before the valley below
it had been excavated, he came upon some loose
columns of a dark compact stone which had fallen
from the edge of the overlying sheet of lava. He
found similar columns standing vertically all along
the mural front of the lava, and observed that they
were planted on a bed of scoriae and burnt soil,
beneath which lay the old granite that forms the
foundation rock of the region. He noticed still
1 See for instance Wallerius' Mineralogia (1773), i. p. 336, replied
to by Desmarest, Mem. Acad. Roy. Sciences (1774), p. 753.
The stages of his research on Basalt 1 5 1
more perfect prisms a little further on, belonging
to the same thin cake of dark stone that covered
the plain which leads up to the foot of the great
central puy.
Every year geological pilgrims now make their
way to Auvergne, and wander over its marvellous
display of cones, craters and lava-rivers. Each one
of them climbs to the plateau of Prudelle, and from
its level surface gazes in admiration across the vast
fertile plain of the Limagne on the one side, and
up to the chain of the puys on the other. Yet
how few of them connect that scene with one of
the great triumphs of their science, or know that
it was there that Desmarest began the observations
which directly led to the fierce contest over the origin
of basalt !
That cautious observer tells us that amidst the
infinite variety of objects around him, he drew no
inference from this first occurrence of columns, but
that his attention was aroused. He was kept no
long time in suspense on the subject. " On the
way back from the Puy de D6me," he tells us, "I
followed the thin sheet of black stone and recognised
in it the characters of a compact lava. Considering
further the thinness of this crust of rock, with its
underlying bed of scoriae, and the way in which it
extended from the base of hills that were obviously
once volcanoes, and spread out over the granite, I
saw in it a true lava-stream which had issued from
one of the neighbouring volcanoes. With this idea
in my mind, I traced out the limits of the lava,
and found again everywhere in its thickness the
152 Desmarest
faces and angles of the columns, and on the top
their cross-section, quite distinct from each other.
I was thus led to believe that prismatic basalt
belonged to the class of volcanic products, and that
its constant and regular form was the result of its
ancient state of fusion. I only thought then of
multiplying my observations, with the view of estab-
lishing the true nature of the phenomenon, and its
conformity with what is to be found in Antrim
a conformity which would involve other points of
resemblance."
He narrates the course of his discoveries as he
journeyed into the Mont Dore, detecting in many
places fresh confirmation of the conclusion he had
formed. But not only did he convince himself
that the prismatic basalts of Auvergne were old
lava-streams, he carried his induction much further
and felt assured that the Irish basalts must also
have had a volcanic origin. u I could not doubt,"
he says, " after these varied and repeated observa-
tions, that the groups of prismatic columns in
Auvergne belonged to the same conformation as
those of Antrim, and that the constant and regular
form of the columns must have resulted from the
same cause in both regions. What convinced me
of the truth of this opinion was the examination of
the material constituting the Auvergne columns with
that from the Giant's Causeway, which I found to
agree in texture, colour and hardness, and further,
the sight of two engravings of the Irish locality
which at once recalled the scenery of parts of Mont
Dore. I draw, from this recognised resemblance
Discovers the volcanic origin of Basalt 153
and the facts that establish it, a deduction which
appears to be justified by the strength of the
analogy namely, that in the Giant's Causeway, and
in all the prismatic masses which present themselves
along the cliffs of the Irish coast, in short even
among the truncated summits of the interior, we
see the operations of one or more volcanoes which
are extinct, like those of Auvergne. Further, I am
fully persuaded that in general these groups of
polygonal columns are an infallible proof of an old
volcano, wherever the stone composing them has a
compact texture, spangled with brilliant points, and
a black or grey tint."
Here, then, was a bold advance in theoretical as
well as observational geology. Not only was the
discovery of Guettard confirmed, that there had
once been active volcanoes in the heart of France,
but materials were obtained for explaining the origin
of certain enigmatical rocks which, though they had
been found over a large part of Europe, had hitherto
remained a puzzle to mineralogists. This explana-
tion, if it were confirmed, would show how widely
volcanic action prevailed over countries wherein no
sign of an eruption has been witnessed since the
earliest ages of human history.
Desmarest was in no hurry to publish his discovery.
Unlike some modern geologists, who rush in hot
haste into print, and overload the literature of the
science with narratives of rapid and imperfect observa-
tions, he kept his material beside him, revolving the
subject in his mind, and seeking all the information
that he could bring to bear upon it. He tells us that
1 54 Desmarest
in the year following his journey in Auvergne, he spent
the winter in Paris, and while there, laid before the
Intendant of Auvergne the desirability of having the
volcanic region mapped. His proposition was accepted,
and Pasumot, one of the state surveyors, was entrusted
with the task of making a topographical map of the
region from Volvic to beyond Mont Dore. The
whole of the summer of 1764 was taken up with
this work. Desmarest accompanied the geographer,
who himself had a large acquaintance with the minera-
logy of his day. The final result was the production
of a map which far surpassed anything of the kind
that had before been attempted, in the accuracy,
variety, and clearness of its delineations of volcanic
phenomena.
At last, in the summer of 1765, after two years
of reflection, Desmarest communicated to the Academy
of Sciences at Paris the results at which he had arrived.
But even then he showed his earnest desire for the
utmost accuracy and fulness attainable. He kept back
his paper from publication. Next year he returned
to Auvergne, after a prolonged journey through the
volcanic regions of Italy, from the Vicentin and Padua
southwards to Naples and Vesuvius. In 1769 he
once more revisited the volcanoes of Central France,
extending his excursions into the Cantal. In the early
part of the summer of 1771 he again brought before
the Academy the results of his researches on the origin
and nature of basalt, embodying in his Memoir the
mass of material which his extended travel and mature
reflection had enabled him to bring together. But
it was not until three years later, viz., in 1774, that
Publishes kis Memoir on Auvergne 155
his long-delayed essay at last appeared in the annual
volume of the Memoirs of the Academy. Life was more
placid in those times than it has since become. The
feverish haste to be famous, and the frantic struggle
for priority, which are now unhappily so rampant, were
but little known in Desmarest's days. He kept his
work eleven years beside him, enriching it continually
with fresh observations drawn from extended journeys,
and thus making his conclusions rest on an ever-
widening basis of accurately determined fact.
The Memoir, as finally published, was divided into
three parts, two of which appeared together, the third
not until three years later. In the first part, the author
narrated his observations in Auvergne and other dis-
tricts, bearing on the nature of basalt. It would take
too much space here to follow him through his survey
of the regions where he found the evidence which he
brought forward. Let me refer merely to the conclud-
ing pages, in which he states his opinion as to the
origin of the columnar rock which he had tracked with
such diligence from district to district. His account,
he remarks, would be incomplete if he did not indicate
at the same time the materials which have been melted
by the fire in order to produce basalt. He had
collected a series of specimens of granite which he
believed to represent these materials. They had under-
gone different degrees of alteration, some showing still
their spar, quartz or other minerals, while others had
partly undergone complete fusion. He had convinced
himself that various other volcanic rocks besides basalt
had resulted from the fusion of granite, the base of
which may have been completely melted, while the
156 Desmarest
quartz of the original rock remained unchanged. He
was not aware that the difference of chemical com-
position demonstrates that the melting of granite could
never have produced basalt.
These ideas, which we now know to be erroneous,
might readily occur to the early observers. It is
undoubtedly true that pieces of more or less completely
melted granite are to be found among the ejections of
old volcanoes, and the inference would not unnaturally
suggest itself that if our artificial fires, kindled by the
combustion of carbonaceous substances, are sufficient to
melt rocks, the far more gigantic conflagrations of
such combustible materials, caused by natural processes
in the bowels of the earth, when concentrated at one
point underneath a volcano, may fuse the surrounding
and overlying rocks, and expel streams of molten
material. We shall find that Werner adopted this
antiquated opinion, and that through him it became
predominant over Europe, even after more enlightened
conceptions of the subject had been announced. Des-
marest does not, indeed, seem to have had at this
time, if ever, any very definite conception of the origin
of the high temperature within volcanic reservoirs.
Nor had chemistry yet afforded much assistance in
ascertaining the resemblances and differences among
rocks and minerals. His mistakes were thus a faithful
reflex of the limited knowledge of the period in which
he wrote.
In the second part of his Memoir, Desmarest gives
a historical narrative of all that had been written before
his time on the subject of basalt. The most interesting
and important passages in this retrospect are the com-
His brilliant generalisation 157
ments of the author on the writings which he sum-
marises, and the additions which he is thereby enabled
to make to the observations already given by him.
He confesses that, had he begun his investigations
among such isolated patches of basalt as those capping
the hills in Cassel and Saxony, he would never have
been able to affirm that basalt is only a lava. But he
had encountered such perfect demonstration of the
volcanic nature of the rock, tracing it with its fresh
scoriae up to the very craters whence it flowed, that
he could not allow this clear evidence to be invalidated,
or even weakened, by cases where the volcanic origin
had been more or less obscured.
It is at this point in his investigation that the genius
of Desmarest shines with a brilliance far above that of
any of his Continental contemporaries who concerned
themselves with geological problems. Guettard had
clearly indicated the volcanic origin of the puys of
Auvergne, and no great acumen was needed to follow
up the clue which he had thus given. But to trace a
pathway through the maze of lavas of many different
ages, to unite and connect them all in one method of
interpretation, and thus to remove the endless diffi-
culties and harmonise the many apparent contradictions
which beset the investigation, was a task which called
forth the highest powers of observation and induction.
Among the many claims of France to the respect and
gratitude of all students of geology, there is assuredly
none that ought to be more frankly recognised than
that, in her wide and fair domain, she possessed a
region where the phenomena were displayed in un-
rivalled perfection, and that in Desmarest she could
158 Desmarest
claim a son gifted with the skill, patience, imagination,
and originality that qualified him so admirably for
the laborious task which he undertook. His achieve-
ments form one of the most notable landmarks in
the early history of geology.
Desmarest, wandering over the volcanic districts of
Central France, had been profoundly impressed, as
every traveller must be, by the extraordinary varieties
in the condition of the various lava-currents. Some
of these sheets of rock retain still the dark, verdureless,
rugged surfaces which they assumed ages ago when
their molten floods stiffened into stone. Others have
lost their covering of scoriae, and are seen clinging to
the sides of valleys, in positions which seem impossible
for any lava-current to have taken. Others are perched
in solitary outlying sheets on the tops of plateaux,
with no cone near them, nor any obvious source from
which they could have flowed.
Pondering on these apparently contradictory pheno-
mena, Desmarest, with the inspiration of true genius,
seized on the fruitful principle that would alone
explain them. He saw that the varying conditions
of the several lavas were due to the ceaseless influence
of atmospheric denudation. He convinced himself
that the detached outliers of basalt, capping the ridges
and plateaux are really remnants of once continuous
sheets of lava, and that their isolation, together with
the removal of their original covering of scoriae and
slags, is to be ascribed to the operations of rain and
melted snow. The depth of the valleys cut through
these lava-platforms was found by him to be com-
mensurate with the antiquity of the lavas, and with
His interpretation of the Origin of Valleys 1 59
the size of the streams that flowed between the severed
escarpments.
He ascertained that, in proportion to their antiquity,
the lava-streams had lost, one after another, the usual
outward features of the younger sheets. The super-
ficial scoriae had disappeared, and the craters were
worn away, until only scattered outliers of compact
dark rock remained. Yet between this extreme and
that of the most recent eruptions, where the lavas, in
unbroken, rugged, cavernous sheets, extend from their
craters down into the present valleys, where they
have driven aside the running streams, every inter-
mediate stage could be found.
Thus the doctrine of the origin of valleys by the
erosive action of the streams which flow in them,
though it has been credited to various writers, 1 was
first clearly taught from actual concrete examples by
1 Thus by Lyell and Murchison it was ascribed to H. B. de
Saussure, Playfair, and Montlosier, Edin. New Phil. Journ. vol. vii.
(1829), p. 15. In England it has been more commonly assigned to
Hutton and Playfair, and to Scrope. The ascription of the doctrine
to Montlosier was singularly unfortunate. That writer states that it
had been the labour of his life (he was 34 years of age at the time
he wrote) to study the valley system of Auvergne, and that he was
on the point of publishing his opinion that the valleys have been
carved out by the streams which still flow in them, when he dis-
covered that De Saussure had already published the same conclusion.
De Saussure's second volume from which Montlosier quotes was
published in 1786. But Desmarest's memoir, in which the subaerial
origin of the Auvergne valleys was proclaimed, had appeared some
twelve years earlier. Montlosier was acquainted with that Memoir,
for he cites it more than once. The doctrine of the carving out of
valleys by atmospheric denudation became a prominent part of Hut-
ton's theory of the earth. See also ante, p. 121, for Guettard's views.
1 60 Desmarest
Desmarest. The first attempt to trace back the history
of a landscape, to show its successive phases, and to
connect them all with the continuous operation of the
same causes which are still producing like effects, was
made by this illustrious native of France.
So satisfied was Desmarest with the proofs furnished
by Auvergne regarding the volcanic origin of basalt,
that he coined the term " basalt-lava/' with an apology
to the mineralogists, and remarked that when once
the characters of this rock have been appreciated, it
may be recognised everywhere, in spite of the most
stupendous degradation. Casting his eye over the
map of Europe, and noting the localities from which
the occurrence of basalt had been reported, he saw
tv/o great regions of ancient volcanic activity in the
heart of the continent. One of these lay to the east,
along the confines of Saxony and Bohemia into Silesia,
from Freiberg to Lignitz ; the other stretched from
the Rhine above Cologne, through Nassau, Hesse-
Darmstadt, and Cassel.
The map which has been already referred to as
accompanying this remarkable memoir, depicts with
great clearness the grouping of the volcanoes over a
large part of Auvergne. It represents them by distinct
kinds of engraving, so as to show four classes differing
from each other in age and other characters. The
first of these classes includes the younger lava-streams,
not yet cut through by running water, and still con-
nected with their parent cones. The second embraces
those lavas which bear decomposed earthy materials
on their surface, and from which their original craters
have disappeared. In the third class are ranged those
Slow elaboration of his Memoirs 1 6 1
lavas which have been reduced to detached outliers
separated by valleys ; while in the fourth, some isolated
masses are placed which Desmarest thought had been
" melted in place," or erupted where they now appear.
The third part of the memoir, though read with the
second part in 1771, was not published until 1777. In
this essay the author discussed the basalt of the ancients,
and the natural history of the various kinds of stones
to which at different times the term basalt had been
applied.
It is interesting to follow the slow elaboration of his
views through his successive memoirs. We must
remember that, during those busy years, his time and
thoughts were chiefly taken up with the inquiries
into industrial development which the Government
of the day had entrusted to him, and which necessitated
frequent and prolonged journeys, not only in France,
but in other countries of Europe. Being convinced
that the great questions in physical geography which
specially occupied his attention could best be studied in
Auvergne, he returned to that region at every avail-
able opportunity, revisiting again and again localities
already familiar to him, and testing his deductions
by fresh appeals to nature. Four years after his great
monograph on the origin of basalt had been read to
the Academy of Sciences, he presented another essay,
developing still further the ideas of denudation and
successive eruptive periods which had been briefly
sketched in his first communication. The scope of
this new effort may be judged of from its full title :
" On the Determination of Three Epochs of Nature
from the Products of Volcanoes, and on the Use that
1 62 Desmarest
may be made of these Epochs in the Study of Vol-
canoes." This essay was laid before the Academy
in the year 1775. An extract from it appeared after
the lapse of four years, 1 but the full paper was not
published until the year i8o6 2 no less than thirty-one
years after its original preparation. During this long
interval the controversy about the origin of basalt
had extended over most of the countries of Europe,
and had involved the very subjects of which Desmarest
treated. He himself, keenly as the matters in dispute
interested him, took no part in the warfare. In his
memoir he ignores the combatants and their strife,
but quietly repeats and strengthens statements which
he had published a generation before, and which, had
they been properly considered and verified, would have
prevented any controversy from ever arising. This
dispute will further occupy our attention in later
pages of this volume. In the meantime let us consider
the character of Desmarest's long-delayed contribution
to the literature and theory of geology.
The progress of his investigations had led him to
perceive the necessity of correlating the various pheno-
mena connected with ancient volcanoes, and especially
with reference to the questions of their relative age and
of the alterations they have undergone from exposure
to the elements. The facts known to him suggested
an arrangement of them into three groups or epochs,
which were not meant to imply definite periods of
time or precise dates, but would express the idea of
1 Journal de Physique, tome xiii. (i 779), p. 115.
2 Mem. de FInstit. des Science* Math. etPhys. tome vi. (1806), p. 219.
It was read again on ist Prairial, An XII (zoth May, 1804).
His Volcanic Periods 163
a recognisable succession of events. His researches
had assured him that the volcanic history of Auvergne
" formed a whole, which, though incomplete, showed
that Nature had followed the same order of procedure
in the most remote ages as in the most recent times."
In co-ordinating the appearances presented by the
different volcanic masses, he began with the considera-
tion of what were obviously the youngest, on the
principle that the last operations of Nature are simpler,
and have undergone less modification from the in-
fluences which are continually changing the face of
the land. He perceived that volcanoes are only tem-
porary accidents in the midst of the ordinary and
normal operations of nature, that the materials erupted
by volcanoes, at various intervals from a remote
antiquity, must have suffered from the universal
degradation, and that the extent of their waste would
be proportionate to the length of time during which
the loss had been continued. The latest lavas must
unquestionably present most nearly the primitive forms
of volcanic masses, and should thus serve as a standard
for comparison, to be kept before the eyes of every
observer who would judge correctly of the extent and
progress of the alteration that is to be seen in other
regions.
The first of his three periods includes the products
of still active and recently extinct volcanoes. These
are distinguished by the association of crater-bearing
cones of cinders and scoriae, with streams of rugged
lava, which can be followed from the cones into the
surrounding country over which they have flowed.
The most modern lava-streams are not cut through
1 64 Desmarest
by valleys, but form continuous sheets. Yet within
the limits of this first epoch proofs of alteration mani-
fest themselves. The loose scoriae and cinders are
washed down to lower levels, the cones are attacked
and the lavas begin to be trenched. As these changes
advance, the flow of running water gradually cuts
through the sheets of lava, and forms valleys across
them. The epoch embraced all the ages required
for this erosion, and during its continuance repeated
outflows of lava took place. Each of these currents
of melted rock would seek the lowest levels, and would
thus mark the valley-bottom of its time, in the long
process of excavation.
In the records of the second epoch, the scoriae and
ashes have been swept away, the cones have entirely
disappeared, and the streams of lava have been cut
into separate patches by the erosion of the valleys,
above which they are now left perched as high plains
or plateaux. Notwithstanding the stupendous results
thus achieved, Desmarest seeks no vast terrestrial dis-
turbance to account for them. He finds their explana-
tion in the working of the very same meteoric agents
which are still carrying on the same process of degrada-
tion. The cellular parts of the lavas, under the
influence of the weather, crumble down into mere
loose earth, which is easily washed away by rain and
melted snow, leaving only the harder and more
resisting core of more solid rock. In like manner,
the loose materials of the cones are removed, until
perhaps only masses of lava remain behind that may
have solidified at their bottoms. By this series of
operations an entire transformation is wrought on the
His Volcanic Periods 165
face of the country. Lavas which originally covered
the floors of valleys, as the ground around them is
lowered, are at last turned into high tablelands, and
are still further cut through and separated into
detached portions, according to the multiplication and
deepening of the ravines and valleys by which they
are traversed. To realise the ancient continuity of
these venerable lava-sheets, we must in imagination
fill up the valleys, and thus restore the slope or plain
over which the molten rock originally flowed.
As all the scoriae and craters are gone, the only way
of detecting an eruptive centre in the volcanic products
of this epoch is to find the point of common origin
for several streams, such points being often marked
by large isolated patches of lava (culots).
Desmarest arrives at the important conclusion that
the lavas of his second epoch were erupted before the
excavation of the present valleys out of the original
plain over which the streams of basalt were poured.
The volcanic events of which they are the memorials
must thus go back to a remote antiquity, for the
erosion of valleys is obviously an exceedingly slow
process. But these lavas are evidently much younger
than the horizontal sedimentary strata and the granite
which these strata overlie, both of these groups of
rock being also trenched by the valleys.
The third and most ancient epoch is denoted by a
series of lavas, which, instead of overlying the sedi-
mentary strata, underlie them or are interstratified
with them. These sediments are now recognized as
the deposits of one of the old Tertiary lakes of Europe.
Their layers are full of land-plants, land and fresh-
1 66 Desmarest
water shells, and remains of terrestrial mammals. But
to Desmarest they were proofs of the former presence
of the sea over the heart of France. He inferred that
the pebbles of various lavas which he found among
these strata denoted former volcanic eruptions, before
the accumulation of the marine deposits. But he
noticed also indications of the discharge of lava
during the sojourn of the sea over this region. He
believed that his third epoch must have lasted some
considerable time, so as to permit the deposition of
600 or 900 feet of horizontal sediments above the
lowest lavas. 1
He remarks that from ignorance of this method of
following the sequence of eruptions and the effects
of continuous waste, naturalists had failed to detect
the existence of lavas of the second and third epochs
in districts where eruptions of the first epoch were
no longer to be recognized. These observers, he
contended, had misread the evidence of nature,
referring what were undoubtedly volcanic rocks to
deposition from water, to schists, and to pierre de
come, and on the other hand mistaking for volcanic
craters what were only hollows dug out by running
water in the lavas of the second, or even of the first
epoch.
1 In the article "Auvergne" in his Geographic Physique^ p. 882
(published in 1803), he briefly summarises his three epochs thus " I
have distinguished three kinds of volcanoes in Auvergne, first, ancient
volcanoes ; second, modern volcanoes ; and third, submarine vol-
canoes." Probably most of the lavas of his third epoch are rather
of the nature of intrusive sills. The subject of ancient volcanic
rocks interstratified among sedimentary deposits is discussed in
chapter viii.
His cautions generalisations 167
The sagacity of these generalisations has been amply
sustained by the reseaiches of later times. Alike in
volcanic geology and in the doctrines of denuda-
tion, the labours of Desmarest marked the rise of a
new era in the investigation of the past history of
the earth. They showed how patient detailed research
could solve some of the most transcendently interesting
problems in geology, and how the minute and philo-
sophical investigation of one small area of the globe
could furnish principles of universal application.
In one respect, perhaps, this far-seeing observer
seems to have been almost afraid to push his views of
denudation to their logical conclusion. There occur
in Central France many flat, isolated areas of basalt,
capping detached hills and fragments of plateaux,
not apparently connected with any visible lava-current
or centre of eruption. The origin of these patches
(called by him " culots "), was explained by supposing
them to mark the positions of volcanic vents up
which the melted material had risen without flowing
out, and where it had solidified within the crater,
being retained by the encircling wall of scoriae and
cinders. The removal of the surrounding loose
material would, he thought, leave the lava as a cake
with steep scarped sides crowning the slopes below.
Possibly some of his culots originated in the way
supposed, but there can be little doubt that most of
them are remnants of lava-streams reduced to almost
the last stage by the progress of denudation.
From the long intervals which he allowed to elapse
between the presentation of his papers to the Academy
and their final publication, it might be supposed that
1 68 Desmarest
Desmarest was probably of a procrastinating, possibly
even of an indolent, temperament. Yet, when we
consider the amount of work, official and scientific,
which he accomplished, we must acquit him of such
an imputation. His voluminous reports on the various
industries of France show how actively and zealously
he laboured in his official harness. But perhaps the
best proof of his indefatigable industry was his colossal
Gtographu Physique, which he undertook as part of the
famous Encyclopedic Methodique founded by Diderot and
D'Alembert. The exhaustive treatment of his subject
may be inferred from the fact that after devoting to
it four massive quarto volumes of from 700 to 900
pages each, he had only got to the letter N when
death closed his labours.
The first volume of this great work is in many
respects the most interesting. The author in his
preface tells how he means to exclude from his task
all discussion of theories of the earth, for, as he
frankly confesses, he had long looked upon these
theories as utterly opposed to the principles of Physical
Geography. But on second thoughts, as unfortunately
such theories really existed, having much the same
relation to Physical Geography that fable bears to
history, he had resolved to give a summary of the
subject, thus conforming to the practice of some
writers who begin their histories with a brief mention
of the heroic times. 1 Accordingly he devotes the
first volume to notices of the more important authors
who had treated of his subject, excluding those who
were still alive. He made, however, exceptions to
1 Geographie Physique, vol. i. (1794), preface.
His Physical Geography 169
this exclusion in favour of Pallas and Hutton.
Though he undertook to present merely an impartial
summary of the opinions of other writers, it is
instructive to have these summaries from the hand
of a man like Desmarest, who was contemporary with
many of those of whom he discourses. The inter-
spersed comment and criticism in his notices are
specially valuable.
The other three volumes were devoted to descrip-
tions of places, districts, and countries, and to articles
or subjects in Physical Geography a branch of know-
ledge which Desmarest regarded as embracing two
equally important and closely related subjects the
interior structure of the globe and its external form.
Geology was not yet admitted to a formal place among
the sciences, but geological questions occupy a promi-
nent place in the massive quartos of the Encyclopedic
Mtthodique. 1
The delays that attended the publication of Des-
marest's important and original observations and de-
ductions respecting the volcanic geology of Auvergne
reached their climax in the case of his detailed map of
that region. We have seen that at his instigation a
topographical survey of Auvergne on a large scale was
begun as far back as 1764, and that reductions of
this map accompanied his Memoirs presented to the
1 Vol. i. of the Geographic Physique appeared in An III (1794);
vol. ii. in 1803 ; vol. iii. in 1809, and vol. iv. in 1811. Among
the geological articles of interest in these volumes reference may
be made to those on Antrim, Auvergne, Basalte, Chaussee des
Geans, and Courans. Vol. v., left unfinished by Desmarest, was
continued by Bory de St. Vincent, Doin, Ferry, and Huot, and
was not published until 1828.
170 Desmarest
Academy of Sciences. The map itself, however, with
all its elaborate detail, bearing on the history of the
volcanoes of Central France, still remained in his
hands. Year after year he sought to bring it nearer
to his ideal of perfection. Every part of the region
had been scrupulously examined by him, every puy
was set down, every crater was carefully drawn, every
current of lava was traced out from its source to its
termination, every detached area of basalt was faith-
fully represented. By a system of hachures and signs
the modern and ancient lavas were discriminated. But
he still kept the work back, and when he died it
remained unpublished.
Of all his contributions to the progress of geology,
this map must be considered the most memorable.
It was the compendium of all his toil in Auvergne,
and showed, as in a model, the structure of the country
which he had so patiently and successfully elucidated.
The reduced map published in his first Memoir and
the portions of the map issued with his second Memoir,
were all that he allowed to appear in his lifetime,
but they failed to impress the minds of his con-
temporaries, as the entire map would have done, with
its complete and clear delineation of the whole district.
Labouring after a perfection which he could not attain,
he not only lost the credit which the map would
have brought him in his lifetime, but he retarded
the progress of the sound views which he himself
held and wished to see prevail. Had this truly admir-
able map been published by him, together with a
general description of the volcanoes depicted on it, his
name would have been placed at once and by universal
His Character 171
assent at the head of the geologists of his day,
and the miserable controversy about the nature of
basalt would either never have arisen, or could have
been speedily set at rest. Cuvier tells us that
Desmarest himself was fully conscious of the desira-
bility of publishing the map, but his life slipped away
as he still aimed at further improvement of it. Yet
he could not bear that other observers should enter
his volcanic region and describe its features. It used
to be said that he seemed to look on Auvergne as his
own property, and certainly he was the legitimate owner
of many of the observations made there after -him.
Cuvier, who knew him well and who had watched
with interest his declining years, gives us a vivid pic-
ture of Desmarest. The illustrious geologist was little
fitted to push his way in a society where the most
successful art was that of self-advertisement. He took
no more pains about his private interest than he did
about his rights in regard to scientific discovery, im-
portuning neither the dispensers of fortune nor those
of fame. With his crust and his cheese, he said, he
needed no Government help to visit the manufac-
tories or the mountains. In short, in studying all
the processes of art, all the forces of nature, he had
entirely neglected those arts that sway the world,
because nothing which agitates the world could move
him. Even works of wit and imagination remained
unknown to him, because they did not lie within the
range of his studies. His friends used jocularly to
affirm that he would have broken the most beautiful
statue in order to ascertain the nature of an antique
stone, and this character was so widely given to him
172 Desmarest
that at Rome the keepers of the museums felt some
alarm in admitting him. In society, too, things, what-
ever they might be, affected him on one side only.
For instance, when an Englishman was recounting
at the house of the Duchesse d'Anville the then recent
thrilling incident in Cook's first voyage, when his
vessel, pierced by a point of rock, was only saved
from sinking by the stone breaking off and remaining
fixed in the hole, every one present expressed in his
own way the interest he felt in the story. Desmarest,
however, quietly inquired whether the rock was basaltic
or calcareous.
A character so little affected by external things
was naturally immovable in regard to relations and
habits. From the earliest days when he began to
be known, he had been engaged to pass his Sundays
at Auteuil with a friend. Ever afterwards he would
appear there on the usual day, even when his friend
was dead, and when age no longer allowed him to
enjoy the country ; and as he had from the first
gone on foot, he always went there on foot until he
was eighty-five years old. All that his family could
then prevail upon him to do was to take a carriage.
Nor was he less constant in more trivial affairs.
Never did he dine or go to bed later one day than
another. Nobody remembered ever to have seen him
change the cut of his clothes, and down to his last
days his wig and his coat recalled the fashions in
vogue under the Cardinal de Fleury.
After recalling his kindliness and helpfulness to
poor inventors, for whom he ever evinced the heartiest
sympathy, his biographer concludes in eloquent words,
The Close of his Career 173
with which I may fitly close this sketch of Desmarest's
career. " The Academy of Sciences saw in him, as
it were, the monument of a bygone age, one of those
old philosophers, now too few, who occupied only
with science, did not waste themselves in the ambitions
of the world, nor in rambling through too wide a
range of study, men more envied than imitated, who
have supplied us with that succession of octogenarians
and nonagenarians, of which our history is full.
Living like these worthies, Desmarest fulfilled a similar
career, and reached, without infirmities or any grave
malady, the age of ninety years. He died on the
2oth September 1815.
"During his protracted lifetime, he saw the Academy
twice renewed. Among so large a number of col-
leagues he doubtless recognised that there were many
who equalled or even surpassed him in enlightenment
or in mental power, but he had the happiness to be
assured that his name would last as long as that of
any one among them."
For the sake of continuity in the narrative, I have
traced the labours of Desmarest from their beginning
to their close without adverting to those of his con-
temporaries. His views regarding the volcanic origin
of Basalt were adopted by a number of good observers,
among whom reference may be made to Raspe, 1
1 R. E. Raspe (1737-1794) had a singularly eventful life. Born
in Hanover of poor parents, he obtained his education at the Univer-
sities of Gottingen and Leipzig, and obtained an appointment at
the latter, where he translated the philosophical works of Leibnitz.
After various changes of occupation, he became keeper of the collection
of antique gems and medals, and began to study geological subjects.
In 1769 he communicated to the Royal Society of London a paper
174 Desmaresfs Contemporaries
Fortis, 1 Dolomieu, 2 Faujas de St. Fond, Montlosier,
and Breislak. 3 But a still more numerous and more
on the former existence of mammoths in the northern regions, and
was afterwards elected an honorary Fellow of the Society. His
industry and the wide range of subjects on which he employed his
facile pen were truly remarkable. In 1775, after being sent to Italy
to collect antiquities and other objects for the Landgrave of Hesse, he
was accused of peculation, and was arrested. He succeeded, how-
ever, in escaping to England and spent there the remainder of his
life. He spoke and wrote English well, and among the works which
he published in this country was an interesting little volume entitled
An Account of some German Volcanoes and their Productions (1776).
Turning his knowledge of minerals to account, he obtained a pre-
carious, and apparently not always honest, livelihood as a mining
prospector. He is understood to have been the prototype of Douster-
swivel in Scott's novel The Antiquary. But his chief title to fame
must be admitted to be his authorship of the original Baron
Munchauserfs Travels. He had finally to escape to a remote part
of Ireland, and died at Muckross in 1794.
1 J. B. A. Fortis (1741-1803) was born at Padua and was educated
for the church in the order of St. Augustine, but was eventually
allowed to spend his time in travel, which he did with much success
in regard to the natural history and antiquities of Dalmatia and
the other tracts visited by him. He was not only a naturalist
and learned man, but also a poet and author of verses on love and
friendship. He wrote many papers on the geology of different parts
of Northern Italy. Having accompanied Desmarest in his excursion
through the volcanic parts of that region, he adopted the views of
the French geologist as to the origin of basalt, but he indulged his
fancy in supposing the heat caused by the eruptions of the Vicentin
to have been so great as to raise the temperature of the Adriatic to
such a degree as to permit tropical species to live in its waters. His
Memoires pour servir a FHistoire Nature lie et principalement a. I'Orycto-
graphie de Fltalie et des pays adjacents were published in two volumes
at Paris in 1802.
2 See/0j#rf, p. 254.
3 For notices of these geologists, see postea, pp. 255-258.
His dislike of Controversy 175
blatant band, urged on its way by Werner, opposed
these doctrines. Although the controversy raged
through Desmarest's life, he took, as I have said, no
share in it. He made an occasional allusion to the
disorder and confusion that had been introduced into
a question which in itself was simple enough to those
who knew how to look at the actual facts. He
asked reproachfully what would become of natural
history and mineralogy, if every question were treated
as that concerning Basalt had been ? And he wrote
somewhat scornfully of the authors who, without
having ever undertaken any researches of the kind
themselves, ventured in discussing those of others to
indulge in unfounded hypotheses. 1 When any belated
straggler from the enemy's camp came to consult
Desmarest on the subject in dispute, the old man
would content himself with the answer, "Go and
see."
Leaving this controversy for subsequent considera-
tion in connection with its later developments, I will
pass from the subject for the present, for the purpose
of calling attention in the following chapter to a
contemporary event which was one of the most inter-
esting features in the scientific life of the latter half
of the eighteenth century the rise of the spirit of
scientific travel.
1 See the article "Basalte" in vol. iii. of the Geographic Physique,
published 1809.
CHAPTER VI
THE Rise of Geological Travel Pallas, De Saussure.
OF all the physical events that happened in the latter
half of the eighteenth century, there was probably none
so fruitful in fostering, among the civilized countries
of the world, an emulation in discovery and research,
as the transit of Venus, which occurred in the summer
of 1769. To that event we owe the voyages of Cook,
and all the rich harvest of results which they added
to our knowledge of the geography of the globe.
What England did on the ocean, it was reserved for
Russia to rival on the land. The Empress Catherine
II. had been irritated by the sarcastic remarks made
by a French astronomer who had travelled to Russia
to observe the previous transit of Venus in 1763, and
she is even said to have been at the trouble of refuting
them herself. At all events, she resolved to do with-
out foreign assistance for the second transit. Deter-
mined that the work should be done thoroughly, and in
such a way as to redound to the glory of her reign, she
commissioned the Academy of Sciences of St. Peters-
burg to organize the expedition. This undertaking
was conceived in a truly imperial spirit. Not only
Empress Catherine's Survey of Russia 177
were astronomers sent out for the more immediate ob-
jects of the research, but advantage was taken of the
occasion to despatch a competent band of observers for
the purpose of penetrating into every region of the vast
empire, and making known its condition and resources.
The instructions drawn up for the guidance of the
explorers were of the most exhaustive kind. Accurate
observations were to be made in the geography and
meteorology of each region visited, the positions of
the principal places were to be astronomically deter-
mined, the nature of the soils, the character of the
waters, and the best means of reclaiming the waste
places were to be accurately observed. The travellers
were to enquire into the rocks and minerals, and to
attend to the outer forms and internal composition
of the mountains. They were further to carry on
careful researches among the plants and animals of
each territory, and, in short, to obtain as much accurate
information as possible in every department of natural
history. Nor were the social problems of life for-
gotten. The expedition was further instructed to pay
special attention to the various races of mankind met
with in the journeys, and to report on their manners,
customs, religions, forms of worship, languages, tradi-
tions, monuments and antiquities. They were likewise
enjoined to take note of the condition of agriculture,
of the maladies that affected man and beast, and the
best remedies for them, of the cultivation of bees and
silk-worms, the breeding of cattle and sheep, and
generally of the occupations, arts, and industries of
each province.
A survey of this complete nature, carried over so
178 Pierre Simon Pallas
vast a region as the Russian Empire, demanded much
skill, labour and time. It was fortunately entrusted
to a man in every way qualified for the task Pierre
Simon Pallas (1741-1811). The whole expedition
comprised seven astronomers and geometers, five
naturalists and several assistants. Starting from St.
Petersburg in June 1768, they traversed the vast
empire to its remotest bounds, making many journeys
in every direction. After six years of unwearied
labour, and almost incredible suffering and privation,
during which Pallas had from time to time sent home
accounts of his more important observations, he re-
turned in July 1774.
Never before had so large a store of observations
in all departments of natural history, extending over
so wide a region of the earth's surface, been gathered
in so brief a time. Pallas wrote his results in German
(his native language, for he was born at Berlin), and
sent them home as they were ready. They were
published at St. Petersburg between 1772 and 1776,
in three quarto volumes. Translated into French,
the work afterwards appeared at Paris during the
years from 1788 to I793, 1 in five handsome quartos,
with a folio atlas of plates.
Pallas was an accomplished naturalist, and made
some original and valuable contributions to zoology.
But it is only with his geological work that we are
here concerned. One of the geological questions
which especially interested him was the occurrence of
the remains of huge pachyderms in the superficial
1 Another edition of this translation appeared in 8 volumes 8vo,
and was reprinted at Bale in 1806.
Fossil Pachyderms of Siberia 1 79
deposits of the north of Siberia. These remains, as
far back as the later years of the seventeenth century,
had been known to exist, for a trade in the ivory
tusks of fossil elephants from the Siberian coasts and
rivers had before that time been carried on. The
actual bones of these animals were subsequently dis-
interred by observers capable of describing their mode
of occurrence, so that Pallas had his curiosity much
excited by the accounts which had already been pub-
lished. There was still much to be found out regard-
ing these strange relics of the frozen north, and Pallas
determined to investigate the subject in the fullest
detail. He kept his eye open for every trace of fossils
of any kind, and one of the most valuable parts of his
labours is to be seen in the precision with which he
chronicles every fossiliferous locality. But the most
astonishing feature of his journeys in this respect was
the proofs he obtained of the almost incredible num-
ber of bones and tusks of the huge pachyderms. The
whole vast basin of Siberia lying to the east of the
Ural mountains, and north of the Altai chain to the
shores of the Arctic Ocean, was found by him to be,
as it were, strewn with these remains. He noticed
that the bones belonged to species of elephant, rhino-
ceros and buffalo, and in one case he saw parts of the
carcase of a rhinoceros still retaining its leather-like skin
and its short hairs. From the abundance of hair on
some parts of the skin of these animals, he inferred that
the rhinoceros of Siberia could live in a more temperate
climate than its living representatives now enjoy.
But undoubtedly the most important contribution
made by Pallas to geological investigation is to be
180 Pallas
found in his memoir on the formation of mountains
and the changes that have taken place on the globe,
particularly with regard to the Empire of Russia. 1 The
highest mountains, he remarked, are composed of
granite, with various schists, serpentine, grits, and
other bedded masses in vertical or highly inclined
positions. These formed his Primitive band, and in
his opinion were older than the creation of organized
beings, for no trace of organic remains was to be
found in any part of them.
The primitive schistose band of the great chains is
immediately succeeded by the calcareous band, which
consists first of solid masses of limestone, either con-
taining no marine productions or only slight traces
of them. The thick beds of limestone are placed at
high angles and parallel to the direction of the chain,
which is also generally that of the schistose band.
As they recede from the line of the mountains, the
limestones rapidly sink down into a horizontal position,
and soon appear full of shells, corals and other
marine organisms. These upheaved limestones form
the Secondary mountains of Pallas. A third series of
rocks, which seemed to him to be the record of some
of the latest revolutions of the globe, consists of sand-
stones, marls, and various other strata, forming a
chain of lower hills in front of the limestone range.
To this series of deposits he gave the name of Tertiary
mountains. 2
1 Act. Acad. Set. Imp. Petropolit. 1777, pp. 21-64.
2 A threefold classification of the rocks was also made by Arduino
in Northern Italy and by Lehmann in Germany, as will be more
particularly referred to in the following chapter.
His threefold grouping of Rocks 1 8 1
These geological terms, thus proposed by Pallas,
were not of course used by him in their more precise
modern definition. We know, for example, that his
Tertiary mountains consisted mainly of the younger
Palaeozoic sediments which are now called Permian,
and that with these ancient formations he included the
much younger sands and clays that inclose the remains
of mammoth, rhinoceros and other extinct mammals.
The main value of his observations lies in his clear
recognition of a geological sequence in passing from
the centre to the outside of a mountain-chain. He
saw that the oldest portions were to be found along
the axis of the chain, and the youngest on the lower
grounds on either side. He recognized also that the
sea had left abundant proofs of its former presence
on the land, he thought that its level had never been
more than 100 fathoms higher than at present, and
he supposed that the elevation of the mountains had
been caused by commotions of the globe. 1
We now pass from the Ural chain, which served
Pallas as his type of mountain-structure, to another
and more famous group of mountains, where, during
the same period, another not less zealous explorer
was at work. The labours of De Saussure among
the Alps mark an epoch, not only in the investi-
gation of the history of the globe, but in the relations
of civilized mankind to the mountains which diversify
the surface of the land.
Up till towards the end of the eighteenth century
1 See the summary of Pallas's views given by D'Archiac in his
Cours de Paleontohgie Stratigraphique, p. 159, 1862. For a fuller
exposition consult Journal de Physique, xiii. (1779), pp. 3 2 9"35*
1 82 Horace-Benedict de Saussure
mountain-scenery was usually associated in men's
minds with ideas of danger, and repulsion. Every
reader of English literature will remember passages,
alike among poets and prose-writers, wherein the
strongest abhorrence is expressed for the high, rugged
and desolate regions of the earth. These tracts,
which seemed at that time to have in themselves
no attractions, were generally looked upon as best
seen from a distance, and not to be entered or
traversed save on the direst compulsion.
The first step in the breaking down of this pre-
judice, which we all now laugh at, was made by the
scientific researches of Horace-Benedict de Saussure
(1740-1799), from which we may date the rise of the
modern spirit of mountaineering. He it was who first
taught the infinite charm and variety of mountain-
scenery, the endless multiplicity of natural phenomena
there to be seen, and the enthusiasm which the
mountain-world will awaken in the heart of every
responsive climber. How few among the thousands
who every year repair to the Alps, the Pyrenees,
the Caucasus, or who find their way to the peaks of
the Rocky Mountains and the Sierra Nevada, are
aware of the debt they owe to the great geologist of
Geneva !
De Saussure was born in that city in the year 1740.
His career at college was so distinguished that at
twenty years of age he became a candidate for a pro-
fessorship of mathematics, and at two-and-twenty ob-
tained one of philosophy. Trained in physical science,
he acquired habits of exactitude in observation and
reasoning, which stood him in good stead in the
His love of Mountains 1 8 3
scientific life to which he eventually devoted himself.
Botany was his first love, and after a long and fruitful
devotion to other parts of the domain of science, it
was to plants that he turned again at last in the
closing years of his life. Amidst his laborious cam-
paigns in the Alps, the plants of the mountains never
lost their charm for him. Among the highest crests,
surrounded by all that is most impressive in Nature,
and occupied with the profoundest problems in the
history of the globe, he would carefully gather the
smallest flower and mark it with pleasure in his note-
book. 1
De Saussure's attitude towards his native mountains
may be inferred from a few of the sentences with which
he prefaces his immortal work. " It is the study of
mountains which above all else can quicken the pro-
gress of the theory of the earth or geology. The
plains are uniform, and allow the rocks to be seen
only where these have been excavated by running
water or by man. The high mountains, on the other
hand, infinitely varied in their composition as in
their forms, present gigantic natural sections wherein
the order, the position, the direction, the thickness
and the nature of the different formations of which
they are composed, as well as the fissures which
traverse them, can be seen with the greatest clear-
ness and at one view. Nevertheless, to no purpose
are these facilities of observation offered, if those
who propose to study the question do not know
how to consider these grand objects as a whole and
in their widest relations. The sole object of most
iCuvier, " loge de Saussure," Stages, vol. i. p. 411.
184 H. B. de Sans sure
travellers who call themselves naturalists is to collect
curiosities ; they walk, or rather they crawl, with their
eyes fixed on the ground, picking up little bits here
and there, without aiming at any general observations.
They are like an antiquary who at Rome, with the
Pantheon and the Colosseum in front of him, should
scrape the ground to seek for pieces of coloured
glass without ever casting his eyes on the architecture
of these superb edifices. It is not that I advise the
neglect of detailed observations. On the contrary, I
look upon them as the only basis of solid knowledge.
But while we gather these details, I desire that we
should never lose sight of the great masses, and that
we should always make a knowledge of the great
objects and their relations, our aim in studying their
small parts.
" But to observe these mighty masses we must not
content ourselves with following the high-roads, which
nearly always wind through the valleys, and which
never cross the mountains, save by the lowest passe. 1 .
We must quit the beaten tracts, and climb to the
lofty summits, whence the eye can take in at one
sweep a multiplicity of objects. Such excursions are
toilsome, I admit ; we must relinquish carriages, and
even horses, endure great fatigue, and expose ourselves
sometimes to considerable danger. Many a time the
naturalist, when almost within reach of a summit on
which he eagerly longs to stand, may doubt whether he
has still strength enough left to reach it, or whether he
can surmount the precipices which guard its approaches.
But the keen fresh air which he breathes makes a
balm to flow in his veins that restores him, and the
His geological opinions 185
expectation of the great panorama which he will enjoy,
and of the new truths which it will display to him,
renews his strength and his courage. He gains the
top. His eyes, dazzled and drawn equally in every
direction, at first know not where to fix themselves.
By degrees he grows accustomed to the great light,
makes choice of the objects that should chiefly occupy
his attention, and determines the order to be followed
in observing them. But what words can describe the
sensations or the ideas with which the sublime spectacle
fills the soul of the philosopher. Standing as it were
above the globe, he seems to discover the forces that
move it, at least he recognizes the principal agents
that effect its revolutions."
De Saussure spent his life among the scenes he so
enthusiastically described, studying the meteorology no
less than the geology of the Alps. As regards the
geological structure of mountains and the origin of
their component rocks, however, he seems hardly
to have advanced beyond the ideas of Pallas. He
believed, with Werner, that the central granite had
resulted from deposition and crystallization in the
waters of a primeval ocean. The vertical or highly
inclined limestones, and other strata flanking the
granite, were for a long time regarded by him as still
in the position in which they were originally deposited.
It was only when he found among these strata layers
of sand and rounded pebbles that he was driven to
admit that there had been some disturbance of the
earth's surface.
Like Pallas and his contemporaries generally, De
Saussure never attempted to set down his observations
1 86 H. B. de Saussure
of the distribution of the rock-formations upon a
map, nor, though he had before him the excellent
sections constructed by Lehmann, to which reference
will be made in the following chapter, did he give
definite expression to his ideas of the mutual relations
of the rocks by constructing a horizontal section even
of the most general and diagrammatic kind. It is
thus a somewhat laborious task to gather from his
Voyages dans les Alpes what precisely were the opinions
he held in regard to tectonic questions. To him,
however, so far as I have been able to discover, we
owe the first adoption of the terms geology and
geologist. This science had formed a part of miner-
alogy, and subsequently of physical geography. The
earliest writer who dignified it with the name it now
bears was the first great explorer of the Alps. 1
De Saussure's theoretical views underwent some
modification during the prolonged period occupied by
the publication of his work, though they seem never
1 In the year 1778 there appeared at the Hague the first
imperfect edition of De Luc's Lettres Physiques et Morales sur les
MontagneSy in the introduction to which the author states that
for the science that treats of the knowledge of the earth he
employs the designation of Cosmology. The proper word, he
admits, should have been Geology, but he "could not venture
to adopt it because it was not a word in use" (Preface, p. viii.).
In the completed edition of his work, published the next year,
he repeats his statement as to the use of the term Cosmology,
yet he uses Geology in his text notwithstanding (vol. i. pp. 4, 5).
In the same year (1779), De Saussure employs the term Geology
in his first volume without any explanation or apology, and
alludes to the geologist as if he were a well-known species of
natural philosopher. (See his Discours Preliminaire, pp. vii., ix.,
xiv., xvi.)
His mews on plicated strata 187
to have advanced much, notwithstanding his constantly
increasing experience and the enormous amount of
observations amassed by him regarding the rocks of
the mountains.
His first quarto volume appeared in 1779, * ne secon d
in 1786, the third and fourth in 1796. There was
thus an interval of fifteen years during which, with
unwearied industry, he continued to traverse the Alps
from end to end, and to multiply his notes regarding
them. Yet he does not seem ever to have reached
any broad conceptions of stratigraphical succession,
or of orographical structure. When he came upon
strata crumpled and doubled over upon themselves,
he thought of crystallization in place as the cause of
such irregularities. The idea of subterranean disturb-
ance would sometimes occur to him, but for many
years he dismissed it with an expression of his in-
credulity, remarking that " if the underground fires
had been able to upraise and overturn such enormous
masses, they would have left some trace of their
operation, but that after the most diligent search he
had been unable to discover any mineral or stone
which might even be suspected to have undergone
the action of these fires." * He had thus no concep-
tion of any operation of nature other than that of
volcanoes, which could produce great disturbances of
the terrestrial crust. Not only had he met with no
trace of any igneous rock in the Alps, but the granite
veins which he found traversing a schist, and which
he at once regarded as throwing light on the origin
of that rock, were believed by him to be almost
1 Voyages dans les Alpes y vol. iii. (1796) p. 107.
1 88 H. B. de Saussure
demonstrably due to infiltration, as the granite itself
had in his opinion been formed from crystallization
in the waters of the ancient ocean. 1
Even when he found the vertical conglomerate of
Valorsine, and recognized that it must have been
originally deposited horizontally, he refrained from
hazarding a conjecture as to the reason of its position.
" We are still ignorant," he says, " by what cause
these rocks have been tilted. But it is already an
important step, among the prodigious quantity of
vertical strata in the Alps, to have found certain
examples which we can be perfectly certain were formed
in a horizontal position." 2
An important part of De Saussure's work among
the Alps deserves special recognition. Profoundly im-
pressed by the power of running water in the sculpture
of the mountains, he ridiculed the notion that the
valleys had been carved out by the sea. He showed
conclusively that they could only have been excavated
by melted snow, rain and rivers. He appealed to any
map that might first come to hand in corroboration
of his opinion that the valley-system of a country
is intimately connected in origin with the system of
drainage. 3 Hutton quotes largely from the Voyages
dans les Alpes in support of this doctrine, which he
made so essential a part of his theory of the Earth,
and which he derived from the illustrious geologist
of Switzerland.
It is interesting to notice that, among the agenda
which De Saussure inserted at the close of his last
1 Vol. i. pp. 533 et seq. 2 Vol. ii. 690.
3 Vol. ii. 920.
His petrographical studies 189
volume, as the fruit of his long experience, he gives
a chapter of suggestions as to what should be looked
for in regard to organic remains among the rocks.
Some of these suggestions are full of sagacity, and
show that, though he had not followed them in his
own researches, he recognized the importance of the
advice he was giving. One of his admonitions was
" to ascertain whether certain shells occur in the older
rocks but not in the later, and whether it is possible
by their means to fix the relative ages and eras of
appearance of the different species." Another recom-
mendation is " to compare exactly the fossil bones,
shells, and plants with their living analogues and to
determine whether they differ from these." *
One of the most interesting features of De Saussure's
work is exhibited in the care with which he equipped
himself for the study of the rocks of the region that
he undertook to examine and describe. Petrography
was at that time in a very embryonic condition. Lin-
naeus and Wallerius had made a beginning in the
definition of rocks, but Werner's labours had hardly
begun. The Swiss naturalist set himself with his usual
ardour to the study, into which he introduced his ac-
customed order and precision. Among other aids in
his researches, he devised a series of experiments in
fusion, in order to determine for himself the probable
origin of different rocks, and especially to enable him
to decide whether certain varieties could be produced
by the melting of others. It will be remembered that
Desmarest had propounded the doctrine that the basalts
of Auvergne had been formed by the fusion of the
1 Vol. iv. p. 505.
190 H. B. de Sans sure
underlying granite by volcanic fire. De Saussure, when
he began to study these questions, was astonished to
discover how little had been done in the way of ex-
perimental research into the nature of rocks. He
selected various Swiss granites, and found that in no
instance could he reduce them by fusion into basalt.
In case there might be any deficiency in the granites of
his own country, he tried the effects of a high tem-
perature on pieces of granite which he had himself col-
lected in Auvergne, but equally without success. He
then experimented on a granite containing abundant
schorl, and obtained a black vesicular glass sprinkled
with the white grains of infusible quartz. He next
took specimens of different porphyries, and though he
got a compact black enamel, nothing appeared in the
least resembling basalt, whence he concluded that it
could not be from the natural fusion of such rocks
as these that basalt was derived. 1
These experiments are especially interesting, as they
mark the earliest beginnings of experimental geology.
The results obtained from them were negative, and
De Saussure did not advance further along the path
he had thus opened into a domain which was destined
in future to become so fruitful. But his name must
ever be had in honour for the share he took in estab-
lishing the use of direct experiment in the elucidation
of geological problems. He did not live to put in
practice the directions which he left for the further
exploration of the Alps by those who should come
after him. A disease, which perhaps took its rise from
the fatigues and privations of his life among the
1 Vol. i. p. 122-127.
His influence 191
mountains, began to increase upon him after his
fiftieth year. It was aggravated by anxiety on account
of the effect of the French Revolution on his private
resources. After three successive strokes of paralysis
he died in 1799 at the age of fifty-nine years.
De Saussure was the first and most illustrious of
that distinguished band of geologists which Switzer-
land has furnished to the ranks of science. To his
inspiration and example we owe the labours of Merian,
Escher von der Linth, Studer, Favre, and the later
and living observers who have so diligently and
successfully unravelled the complicated structure of
the Alps. His descriptions of a great mountain-chain
form admirable models of careful observation and
luminous narrative. Though he did not add much
to the advancement of geological theory, he contributed
largely to the stock of ascertained fact, which was so
needful as a basis for theoretical speculation. The
data which he collected became thus of the utmost
service to those who had to work out the principles
of geology. To Hutton, for example, they supplied
many admirable illustrations of the geological processes
on which he based his Theory of the Earth. It was
under the guidance of the great Swiss observer that
the Scottish philosopher stood in imagination on the
summit of the Alps, and watched from that high
tower of observation the ceaseless decay of the moun-
tains, the never-ending erosion of the valleys, and that
majestic evolution of topography which he so clearly
portrayed. Among the illustrious men who contri-
buted to plant the foundations of geology, an honoured
place must always be assigned to De Saussure.
CHAPTER VII
HISTORY of the Doctrine of Geological Succession. Arduino,
Lehmann, Fiichsel, Werner.
IN the gradual growth of knowledge regarding the
history of our globe, it is surprising how late men
were in realising that this knowledge must be based
not on mere speculation, but on patient investigation
of what evidence can be gathered from the structure
of the planet itself. Slowly and laboriously the truth
was reached that the rocks which form the terrestrial
crust bear witness to the passage, not of one or two,
but of a whole series of revolutions, that these changes
occupied vast intervals of time, and that while they
varied indefinitely in their local effects from one region
to another, they were but incidents in one vast onward
march of development which embraced the whole
globe within its influence. What we now know as
the doctrine of geological succession, in other words,
the history of the evolution of the earth, during a
prolonged series of ages up to the present time, took
shape with extreme slowness, each generation adding
a little to the basis of fact and to the superstructure
of inference.
Slow growth of Geological Chronology 193
There were in especial two lines of investigation
along which progress could be made. On one of
these, the various masses of rock that are visible over
the surface of the globe had to be studied with a
view to the determination of their origin and sequence.
On the other line, the details of these rock-masses,
and more particularly of the sedimentary series, had
to be worked out, and their organic contents to be
noted, in order to ascertain how far the living creatures
of older times differed from those of the present.
The former of these two branches of research naturally
came to be pursued first. It is by far the more ob-
vious of the two, and considerable progress had to be
made in it before the very possibility of the second
line of enquiry could be recognised and pursued.
We have seen that with all his sagacity and insight,
Guettard gave no indication that he had any ideas as to
the chronological relations of the various groups of
strata which he included in his a bands." Neither
he nor his contemporaries ventured to draw geological
sections. We have found that even De Saussure and
Pallas, though they saw that the rocks of the central
part of the mountain-chains are older than those of
their flanks, did not definitely express their ideas on
this subject in graphic form. Desmarest had clearly
perceived the evidence for a long sequence of volcanic
eruptions in Central France, but he never applied this
evidence towards an elucidation of the general history
of the globe as a whole. Buffon too had vividly
realised the pregnant idea that the earth has passed
through a long evolutional history whereof the monu-
ments are to be gathered from the structure of the
194 Early writers John Strachey
planet itself. But though he worked out this idea
with great logical acumen and brilliant rhetoric, he
had only a slender groundwork of ascertained fact on
which to base his pictures of the successive stages
through which the earth has passed. Such a ground-
work could not be laid down without much patient
detailed observation of the rocks, and a comparison of
the records afforded by them in different countries.
Yet even in Buffon's time the first seeds of Strati-
graphy had been sown which, before the end of the
eighteenth century, were to germinate in so wide an
expansion of geological theory.
In tracing the history of the idea of a chronological
sequence among the rocks of the earth's crust it is
interesting to mark its independent origination in
different countries. In regions where minerals, more
especially coal-seams, had long been worked it was
familiar knowledge that a certain definite order could
be traced among the rock-formations. Thus in Eng-
land, prolonged mining in the coal-fields led to a clear
recognition not only of a local order of arrangement,
but of a sequence which might be capable of wide
application. The first writer in England whose obser-
vations on this subject deserve to be cited is John
Strachey, who contributed two papers to the Philosophi-
cal Transactions in the years 1719 and 1725, in which
he recognised the sequence of the geological formations
in the south-west of the country, enumerating in their
proper order the various leading subdivisions of the
stratigraphical series from the Coal to the Chalk. He
likewise recorded the important fact that while the
Coal-strata are all more or less inclined, the overlying
Arduino, Lehmann 195
formations from the Red Marl upwards lie horizontally
across their edges. 1
In Italy the name of Giovanni Arduino (1713-1795)
is deservedly held in honour for the share which during
his long life he took in upholding the reputation of
the illustrious Italian school of geology. Born near
Verona, he became inspector of mines in Tuscany
and finally professor of Mineralogy and Metallurgy at
Venice. Among his contributions to science it may
be noted that he classified the rocks of the north of
Italy as Primitive, Secondary, Tertiary and Volcanic.
The first of these divisions included the schists and
associated masses which occupy the core of the moun-
tains and contain no organic remains. The second
comprised limestones, marls, shales and other stratified
sedimentary materials, many of which are crowded with
fossils. The third was made up of generally looser
detritus, derived from the disintegration of the other
rocks, and sometimes full of remains of terrestrial
plants and animals. The volcanic group consisted of
lavas and tuff accumulated by repeated eruptions and
inundations of the sea. Thus to Arduino geology is
indebted for the threefold classification of the rocks
of the earth's crust, which amid all the changes of
nomenclature, has survived down to the present time.
Johann Gottlob Lehmann (died 1767) published
at Berlin in 1756 a little duodecimo volume, roughly
printed on poor paper, extending to 240 pages, and
bearing the title Versuch einer Geschichte von Flotz-
Gebiirgen, etc. This unpretending treatise must be
ranked as one of the classics of geological literature.
l Phil. Trans, xxx. (1719) p. 968 ; xxxi. p. 395.
196 Lehmann
It gives the results of the author's own observations
among the rocks of the Harz and the Erzgebirge.
Like Arduino he recognized three orders of mountains,
ist, Those which appeared coeval with the making of
the world ; 2nd, those which arose from a general
alteration of the ground ; and 3rd, those which have
been formed from time to time by local accidents.
The first order is distinguished not only by the
greater height of its members, but by their internal
structure. The rocks are less various, their strata
are not horizontal but vertical or inclined, and their
layers are neither so weak nor so multifarious as those
of the other groups. Nor are they mere superficial
deposits, but they plunge down into unknown depths
into the earth's interior. The second order, or Flotz-
gebirge, are of much younger date, and have arisen
from the successive deposit of sediments from water
that once covered their sites, these sediments being
now seen in flat sheets or strata, piled above each
other to no great height. Lehmann showed that
these sedimentary deposits contain abundant petrifac-
tions, such as remains of wild animals, shells, plants
and trees. He gave a number of sections to show the
order in which the strata succeed each other, remarking
that the coarser sediments were generally lowest, while
limestone came at the top. His profiles of the suc-
cession of strata showed a remarkable grasp of some
of the essential features of tectonic geology. It is
singular that these suggestive examples should not
have had more imitators during the latter half of
the eighteenth century. Nothing could be more
precise and distinct than Lehmann's demonstration
Fuchsel 197
of the stratified nature and aqueous origin of the
younger formations of the earth's crust, or his proofs
that the strata succeed each other in a definite order
in the region with which he was acquainted.
Contemporary with Lehmann, and though less fre-
quently quoted, worthy of a still higher place in the
bede-roll of geological worthies was George Christian
Fuchsel (I722-I773). 1 This remarkable man was
the son of a baker in Ilmenau, at the northern
foot of the Thuringian Forest. He studied at the
Universities of Jena and Leipzig, and having from
an early date addicted himself to minerals and rocks,
he was lucky enough to find a seam of coal at
Mtthlberg, near Erfurt, and still more fortunate to
receive from the proprietor of the ground a reward
of 200 crowns for the discovery. At Erfurt he took
his degree of Doctor of Medicine, and eventually
became physician to the Prince of Rudolstadt. He
lived to the age of only fifty-one, and died in the
year 1773.
His position at Rudolstadt was favourable for the
cultivation of his taste for geological pursuits. To
the south rose the ancient rocks of the Thuringer
Wald, flanked by the great series of Permian and
Triassic formations, regularly superposed upon each
other, and cut out into valleys by the rivers that
drain the mountain range. In the year 1762, when
he was forty years of age, he published one of the
1 For the personal data here given I am indebted to a brief notice
by C. Keferstein in the Journal de Geo/ogie, vol. ii. (1830), p. 191,
and to his account of Fuchsel in his Geschichte und Litteratur der
Geognosie (1840), p. 55 seq.
198 Fuchsel
most remarkable treatises which up to that time had
been devoted to the description of the actual structure
and history of the earth. It was in Latin, and, under
the title of " A History of the Earth and the Sea,
based on a History of the Mountains of Thuringia,"
appeared in the Transactions of the Electoral Society
of Mayence, established at Erfurt. 1 It was illustrated
with a geological map and sections of the country.
Eleven years later he published in German a Sketch of
the most Ancient History of the Earth and Man, which
contained a further development of his geological
views. 2
These views were founded on the author's own
observations in the region where he Jiad been born
and passed his life. He recognized as clearly as
Lehmann, and with more accuracy of detail, the
sequence of stratified rocks resting in gently-inclined
strata against the older upturned masses of the
mountains. He noted the position of the Coal with
its exotic plants, followed by the copper-bearing shales,
Zechstein, mottled sandstone, marls, gypsum, and
finally the Muschelkalk.
Taking no limited or parochial view of the pheno-
mena that presented themselves before his eyes, he
connected the history of his little principality with
that of the whole globe. In the order of succession
1 " Historia terrae et maris, ex historia Thuringiae per montium
descriptionem erecta " (Trans. Elect. Soc. Mayence, vol. ii. pp.
44-209). The map was the first detailed geognostical and petro-
graphical map of a large district in Germany, and the sections
were excellent for their time.
2 Entwurf zu der altesten Erd- und Memchengeschichte, 275 pages,
8vo, 1773.
His sagacious geological mews 199
ot the rocks around him, he saw the records of a
series of changes which the earth had once under-
gone. These changes were conceived by him to have
been of no abnormal kind, but to have resembled
those which might quite possibly occur now, for, in
his opinion, our planet had always presented pheno-
mena similar to those of the present time. He saw
that the existing dry land was in large measure formed
of strata that had once been laid down on the floor
of the sea, like the sandstones, marls and limestones
with which he was familiar. Rising from underneath
these strata, the older and inclined rocks of the
mountains appeared to him as the relics of a more
ancient continent, which had in like manner been
built up of marine sediments. He believed that the
tilted, highly-inclined positions of these rocks were
due to their having tumbled down into the hollow
interior of the earth.
Fiichsel, with much sagacity, not only interpreted
the origin of individual strata, but divined that a
continuous series of strata of the same composition con-
stitutes a formation, or the record of a certain epoch in
the history of the globe, thus anticipating a doctrine
which afterwards took a prominent place in the system
of Werner. All these sediments were originally
deposited horizontally. Where they have been placed
in inclined positions, the alteration was, in his opinion,
to be attributed to some subsequent disturbance, such
as the effects of earthquakes or oscillations of the
ground. To earthquakes also he assigned the pro-
duction of the rents which, being filled from above,
now form veins in the rocks. It was his opinion
200 Fuchsel
that the earthy passage-beds between formations
mark intervening periods of disturbance.
The Muschelkalk in Fttchsel's district forms the
highest of the Secondary formations, and is succeeded
by the various alluvial deposits. These youngest
accumulations, containing only terrestrial remains, were
looked upon by him as having arisen from the action
of a great deluge.
This singularly shrewd observer deserves further
to be remembered for the place which he assigned
to organic remains in his theoretical views of the past
history of the earth. He clearly recognized these
objects as relics of once living things. He saw that
the Coal was distinguished by its land-plants, the
Zechstein by its gryphites, the Muschelkalk by its
ammonites ; further, that some formations contained
only marine remains, others only terrestrial, and thus
that the latter point to the neighbourhood of ancient
land, while the former indicate the presence of the sea.
The clear and detailed evidence brought forward
by Lehmann and Fuchsel, that the materials of the
terrestrial crust had not been thrown down at random,
but succeeded each other in a certain definite order,
and contained a record of former processes and
changes, like those in progress now, ought to have
given at once a great forward impetus to the study
of the history of the earth. Lehmann's volume,
however, was not in itself attractive, and Fiichsel's
first essay, though by far the most detailed and philo-
sophical treatise on the subject that had yet appeared,
was written in Latin, and buried in the publications
of an obscure Society. Fuchsel himself lived quietly
Abraham Gottlob Werner 201
in a little town, with no disciples to spread his
doctrines, so that his very name remained hardly
known even in Germany, while other and much inferior
writers achieved a wide reputation. His writings
seem to have dropped out of sight, until they were
unearthed and brought to notice fifty-seven years after
his death by Keferstein. The seed sown in Germany
by Lehmann and Fiichsel was thus long in springing
into abundant growth. During the remainder of
the century the idea of geological succession was pro-
claimed, indeed, from the housetops, but it was so
mingled with fanciful hypothesis, that its truth and
real value were almost lost sight of.
We come now to the time of the advent of a man
who bulks far more largely in the history of geology
than any of those with whom up to the present we
have been concerned a man who wielded an enor-
mous authority over the mineralogy and geology of
his day. Through the loyal devotion of his pupils,
he was elevated even in his lifetime into the position
of a kind of scientific pope, whose decisions were
final on any subject regarding which he chose to
pronounce them. During the last quarter of the
eighteenth century, by far the most notable figure in
the ranks of those who cultivated the study of min-
erals and rocks was unquestionably Abraham Gottlob
Werner (1749-1817).
The vast influence which this man wielded arose
mainly from his personal gifts and character, and
especially from the overmastering power he had of
impressing his opinions upon the convictions of his
hearers. It was an influence of a curiously mingled
202 IVerner
kind. From one point of view, Werner appears to
us as the enthusiastic teacher, drawing men from all
countries under his spell, and kindling in them much
of his own zeal for the study of minerals and rocks.
In another aspect, he stands out as the dogmatic
theorist, intolerant of opinions different from his own,
training his pupils in an artificial and erroneous system,
and sending them out into the world not patienty
to investigate nature, but to apply everywhere the
uncouth terminology and hypothetical principles which
he had taught them.
Though he himself mixed but little publicly in
the dispute, he was directly the cause of the keen
controversy over the origin of basalt, the echoes of
which had hardly ceased when some of the older
geologists of our day were born. I have myself
known a number of men who remembered well the
acrimony of the warfare, and some of whom even
played the part of combatants in the struggle. Werner
had a large following. He was undoubtedly the most
popular teacher of the science of minerals and rocks
in his time. His services to mineralogy were great,
and have always been freely admitted. By the partiality
of his pupils and friends he was also raised to the
highest eminence as a teacher of geology, and was
even looked up to as the founder of that science.
The noise of conflict, and the plaudits of enthusiastic
disciples have now long been silent. We can calmly
consider what Werner did, in what state he found the
science of the rocks, and in what condition he left
it. As the result of my own investigation in this
subject I have been compelled to arrive at the con-
His childhood 203
elusion that, although he did great service by the
precision of his lithological characters and by his
insistence on the doctrine of geological succession, yet
that as regards geological theory, whether directly by
his own teaching, or indirectly by the labours of his
pupils and followers, much of his influence was
disastrous to the higher interests of geology. The
career of such a man, so full of contradictions, so
preponderant in the studies to which it was devoted,
and so momentous in its effects upon the progress
of science in his own generation, merits the careful
consideration of all who would realise how geology
has gained its present place.
Werner was born on 25th September 1749 at
Wehrau on the Queiss in Upper Lusatia. 1 His
ancestors had been engaged in the iron industry of
that region of Germany for some 300 years. His
father was inspector of Count Solms' foundry, and
at one time it seemed as though the future mineralogist
were to carry on, in the same profession, the traditions
of the family. From infancy he was familiar with
stones. When still hardly able to speak, it was one
of his favourite amusements to break down pieces of
sandstone and marl. After he had begun to learn
his alphabet, his father, as a reward for proficiency
in his lessons, would allow him to look over a small
collection of minerals which he kept in a box, and
1 For the biographical details given in this sketch I am indebted
partly to the " Kurzer Nekrolog Abraham Gottlob Werners," by
K. A. Blode, in the Memoirs of the Mineralogical Society of Dresden,
vol. ii. (1819), p. 249, and partly to the Eloge on Werner by Cuvier.
Blode, who had access to family documents, gives 1749 as the year
of Werner's birth; Cuvier and other authorities make it 1750.
204 Werner
would talk to him about them, their origin and their
uses. Late in life Werner could vividly recall the
very minerals that were the playthings of his child-
hood various ores and spars, as well as some varieties
of which his father did not know the names. When
he could read, his favourite books were lexicons of
mining and manufactures, wherein he specially selected
the articles on mineralogy. His tendencies, thus early
shown, were further fostered by his father, who in
hours of leisure would entertain him with stories of
the mines.
In his tenth year the boy went to school at the
old fortified town of Bunzlau in Silesia, and after a
few years returned in 1764 to assist his father and
become controller of the smelting houses at Wehrau.
But the aspirations he had formed to devote himself
to minerals seem at last to have grown too strong
to be resisted, so that after doing his duty at the
foundries for five years, he resolved to betake himself
in 1769 to the Mining Academy of Freiberg, which
had been founded two years before, and of the
attractions of which he had no doubt heard much.
Amid what was there thoroughly congenial to him,
he threw himself with enthusiasm into the work of
the school, not only availing himself of all the formal
instruction in the art of mining to be had from the
teachers, but visiting all the chief Saxon mines,
especially those of most importance in the Freiberg
district, descending the shafts, joining in the manual
labour of the miners, and thus making himself master
of the whole art of mining, below ground as well
as above. His zeal and capacity were soon recognized
His education 205
by the officials at Freiberg, and before he had been
long there he was offered a place in the Saxon Corps
of Mines. He was not unwilling to accept the
appointment, but determined first of all to prosecute
a wider range of study for a few years at the
University of Leipzig.
Accordingly, after some two years spent in mining
pursuits, Werner went to Leipzig in the spring of
the year 1771, and for the next two years devoted
himself almost entirely to the study of law. In his
third and last year at the University, he seems to
have taken up a miscellaneous series of subjects,
especially modern languages, but he settled down at
last to the prosecution of his first love mineralogy ;
and with such industry and enthusiasm did he pursue
his study, that while in his twenty-fifth year, and still
a " student of the science and law of mining," he
published his first essay a little duodecimo of 300
pages, on the external characters of minerals. 1 We
can imagine the astonishment and delight of the lovers
of mineralogy when they first got hold of this treatise,
and found there, instead of the miscellaneous, isolated,
and heterogeneous observations to which they were
accustomed, an admirably ordered method and a clear
marshalling and co-ordination of facts, such as had
never before been seen in mineralogical literature.
On leaving the University of Leipzig, Werner went
back to his home by the Queiss. It seemed as though
the authorities at Freiberg, who at one time were so
1 " Von den ausserlichen Kennzeichen der Fossilien, abgefasst vdh
Abraham Gottlob Werner, Der Bergwerks-Wissenschaften und
Rechte Beflissenen," Leipzig, 1774.
20 6 Werner
anxious to secure his services, had now forgotten his
existence. He had heard nothing more of the proposal
to engage him, and he began to arrange his plans for
the future. But the officials, though slow in their
movements, had not lost sight of him. They had
made note of his progress at Leipzig, and especially of
his admirable little book, and at last in February 1775,
to his own astonishment, Werner received a call from
them to become Inspector and Teacher of Mining and
Mineralogy in the Freiberg Mining Academy at a
yearly stipend of 300 thalers. He thus attained before
he was twenty-six the position in which he spent the
rest of his life and achieved his great fame. For
some forty years he continued in the same appoint-
ment. By his genius he raised the Mining School
from a -mere local seminary, founded for the training
of a few Saxon miners, to the importance of a great
academy or university, to which as in mediaeval times,
his renown as a teacher drew pupils from all corners
of the civilized world. Men advanced in years, as
well as youths, sometimes even men of science already
distinguished, betook themselves to the acquisition of
German that they might attend the lectures of the
great oracle of geology.
The life of such a man, seldom tempted to stir from
home, immersed in the daily discharge of the duties
of his office, and only varying from year to year the
subject of his prelections, offers little incident to the
biographer. Moreover, though he precociously began
so young as an author, he wrote merely a few short
treatises and papers in journals, thus leaving hardly any
personal memorial behind him. It is from the writings
His figure and character 207
of his pupils that we chiefly learn what manner of man
he was, and what were the special characteristics of his
teaching.
From the portrait of him prefixed to one of his
works, 1 we gather that his large keen eyes looked out
beneath a broad and high forehead, over which his
hair was dressed in the formal wig-fashion of the day,
and turned up in large curls on either side. The
round, smooth-shaven face had, as its most conspicuous
feature, a mouth in which, while the firm lips denoted
decision of character, the upward curve on either side,
combined with a slight dimpling of the cheeks, gave
the impression of great sweetness of disposition, with
a touch of humour, and a certain degree of timidity.
There is moreover a notable trimness of person,
indicative of the exceeding orderliness of his whole
nature.
His personal charm must have been altogether
remarkable. Cuvier tells us with what paternal fond-
ness Werner was accustomed to treat his pupils.
There was no sacrifice of time or energy which he
would not make for their sake, even his slender purse
was at their service, if they ever stood in need of
pecuniary help. When the students crowded round
him, so that only a portion of them could conveniently
see and hear his demonstrations, he would divide them
and repeat his lecture. 2
l New Theory of the Formation of Veins. Translated by Charles
Anderson, M.D. Edinburgh, 1809.
2 There is an enthusiastic account of Werner as a teacher by one
of his pupils, C. A. Bottiger : " Uber Werners Umgang mit seinen
Schiilern," Auswahl. Gesellsch. Mineralog. Dresden, Band ii. p. 305
(1819).
2o8 Werner
His manner of discourse also was so attractive and
stimulating that he riveted the attention of his pupils,
incited them to pursue the studies that he loved, and
fired them with a desire to apply his methods. Osten-
sibly he had to teach mineralogy a science which in
ordinary hands can hardly be said to evoke enthusi-
asm. But Werner's mineralogy embraced the whole
of Nature, the whole of human history, the whole
interests and pursuits and tendencies of mankind.
From a few pieces of stone, placed almost at random
on the table before him, he would launch out into
an exposition of the influence of minerals and rocks
upon the geography and topography of the earth's
surface. He would contrast the mountainous scenery
of the granites and schists with the tamer landscapes of
the sandstones and limestones. Tracing the limits of
these contrasts of surface over the area of Europe, he
would dwell on their influence upon the grouping and
characteristics of the nations. He would connect, in
this way, his specimens with the migration of races, the
spread of languages, the progress of civilization. He
would show how the development of the arts and
industries of life had been guided by the distribution
of minerals, how campaigns, battles, and military
strategy as a whole, had been dependent on the same
cause. The artist, the politician, the historian, the
physician, the warrior were all taught that a knowledge
of mineralogy would help them to success in their
several pursuits. It seemed as if the most efficient
training for the affairs of life were obtainable only at
the Mining School of Freiberg.
By such continual excursions into domains that
Character of his teaching 209
might have been thought remote enough from the
dry study of minerals, and by the clear and confident
method, playful vivacity and persuasive eloquence with
which they were conducted, Werner roused his hearers
to a high pitch of enthusiasm. No teacher of geo-
logical science either before or since has approached
Werner in the extent .of his personal influence, or in
the breadth of his contemporary fame.
Let us now inquire what were the leading character-
istics of his doctrines, and what permanent influence
they exerted upon the progress of the science of his
time. His brilliance and discursiveness might attract
and retain large audiences, but his lectures must have
possessed more solid and enduring qualities, which
inspired his disciples to devote their lives to the
studies into which he introduced them, and filled
them with the ardour of devoted proselytes.
The first feature to which we may direct our atten-
tion, distinguishable in every part of his life and work,
was his overmastering sense of orderliness and method.
This habit of mind became in him a true passion.
He is said to have bought books, rather to arrange
them systematically than to read them. He observed
the details of social etiquette as punctiliously as the
characters of minerals, but with one remarkable excep-
tion, to which I shall afterwards allude ; and he would
deliberate over the arrangement of a dinner with as
much gravity as over that of his library or his
cabinet.
We cannot take up any of Werner's writings with-
out at once noting this prominent peculiarity of his
mind. Every fact, every proposition is definitely
2 1 o Werner
classified and ticketed, and even when he has little or
nothing to say under any particular subdivision, the
subdivision is nevertheless placed in its due niche all
the same.
This methodical habit proved of the greatest service
to the cause of mineralogy. When Werner entered
upon his mineralogical studies, the science of minerals
was an extraordinary chaos of detached observations
and unconnected pieces of knowledge. But his very
first essay began to put it into order, and by degrees
he introduced into it a definite methodical treatment,
doing for it very much what Linnaeus had done some
years before for botany. Like that great naturalist, he
had to invent a language to express with precision the
characters which he wished to denote, so that mineralo-
gists everywhere could recognise them. For this
purpose he employed his mother tongue, and devised
a terminology which, though artificial and cumbrous,
was undoubtedly of great service for a time. Uncouth
in German, it became almost barbarous when translated
into other languages. What would the modern Eng-
lish-speaking student think of a teacher who taught
him, as definite characters, that a mineral could be
distinguished as " hard, or semi-hard," " soft or very
soft," as " very cold, cold, pretty cold, or rather cold,"
as " fortification-wise bent," as " indeterminate curved
lamellar," as " common angulo-granular," or as " not
particularly difficultly frangible " ? l
Werner arranged the external characters of minerals
in so methodical a way, that they could readily be
1 These terms are all taken from the Wernerian system as ex-
pounded in English by Werner's pupil, Jameson (note on next page).
His Geognosy 211
applied in the practical determination of species. Yet
strangely enough he neglected the most important of
them all that of crystalline form. From the in-
dividual minerals, he proceeded to the consideration
of their distribution, and the character and origin of
the different rocks in v/hich they occur. To this
branch of inquiry he gave the name of geognosy,
or knowledge of the earth, and he defined it as the
science which reveals to us in methodical order the
terrestrial globe as a whole, and more particularly the
layers of mineral matter whereof it consists, informing
us of the position and relations of these layers to each
other, and enabling us to form some idea of their
origin. The term geology had not yet come into use,
nor would either Werner or any of his followers have
adopted it as a synonym for the " geognosy " of the
Freiberg school. They prided themselves on their
close adherence to fact as opposed to theory. One
of them, with pointed reference to the writings of
Hutton and Playfair, which had appeared shortly
before, wrote : " We should form a very false con-
ception of the Wernerian geognosy were we to believe
it to have any resemblance to those monstrosities known
under the name of Theories of the Earth. . . . Armed
with all the facts and inferences contained in these
visionary fabrics, what account would we be able to
give of the mineralogy of a country, if required of
us, or of the general relations of the great masses of
which the globe is composed ? " l The geognosts
1 Jameson, "Elements of Geognosy," forming vol. iii. of his
System of Mineralogy, p. 4.2. The italics in this quotation are in
the original.
2 1 2 Werner
boasted of the minuteness and precision of their
master's system, and contrasted the positive results
to which it led with what they regarded as the vague
conclusions and unsupported or idle speculations of
other writers. Werner arranged the crust of the
earth into a series of "formations", which he labelled
and described with the same precision that he applied
to the minerals in his cabinet. He taught that these
formations were to be recognised all over the world,
in the same order and with the same characters. The
students whom he sent forth naturally believed that
they carried with them, in this sequence, the key
that would unlock the geological structure of every
country.
But never in the history of science did a stranger
hallucination arise than that of Werner and his school,
when they supposed themselves to discard theory and
build on a foundation of accurately-ascertained fact.
Never was a system devised in which theory was
more rampant ; theory, too, unsupported by observa-
tion, and, as we now know, utterly erroneous. From
beginning to end of Werner's method and its applica-
cations, assumptions were made for which there was
no ground, and these assumptions were treated as
demonstrable facts. The very point to be proved
was taken for granted, and the geognosts, who boasted
of their avoidance of speculation, were in reality among
the most hopelessly speculative of all the generations
that had tried to solve the problems of the theory of
the earth.
Werner's first sketch of his plan of the structure
of the earth's crust and the succession of the rocks
His Universal Formations 213
that compose it appeared as a thin quarto of only 28
pages, published at Dresden in the year lySy. 1 It
was descriptive rather than theoretical, and was marked
by all its author's precision and orderliness of state-
ment. It contained the essence of his system in its
simplest form. In later years, as we shall see, further
experience compelled him to enlarge and modify the
system, but without changing the fundamental con-
ceptions on which it was founded. The modifications,
however, were not embodied by Werner in any later
edition of his work. They were given by him from
time to time in his lectures, and gradually became
known from the writings of his students. One of the
most devoted and distinguished of these followers was
Robert Jameson, who afterwards became Professor of
Natural History in the University of Edinburgh. He
was mainly instrumental in introducing the Wernerian
doctrines into Britain, and continued for a number of
years to be their most ardent supporter. In many
respects the fullest accounts of Werner's views are
to be found in the various works of the Edinburgh
Professor, and I shall cite some further passages from
them in the present chapter.
One of the fundamental postulates of the Wernerian
doctrines was the existence of what were termed uni-
versal formations. When he elaborated his system,
Werner had never been out of Saxony and the im-
mediately adjacent regions. His practical knowledge
of the earth was, therefore, confined to what he could
1 Kurze Klassification und Beschreibung der verschiedenen Gebirgsarten,
von A. G. Werner, Bergakademie Inspector, und Lehrer der Berg-
baukunst und Mineralogie zu Freiberg. Dresden, 1787.
2 1 4 Werner
see there, and so little was then known of the geo-
logical structure of the globe as a whole, that he
could not add much to his acquaintance with the
subject by reading what had been observed by others,
though there can be little doubt that he stood
greatly indebted to Lehmann and Fiichsel. With this
slender stock of acquirement, he adopted the old idea
that the whole globe had once been surrounded with
an ocean of water, at least as deep as the mountains
are high, and he believed that from this ocean
there were deposited by chemical precipitation the
solid rocks which now form most of the dry land.
He taught that these original formations were uni-
versal, extending round the whole globe, though not
without interruption, and that they followed each
other in a certain order. He affirmed that the first-
formed rocks were entirely of chemical origin, and
he called them Primitive, including in them granite,
which was the oldest, gneiss, mica-slate, clay-slate,
serpentine, basalt, porphyry, and concluding with
syenite as the youngest. Succeeding these came what
he afterwards separated as the Transition Rocks,
consisting chiefly of chemical productions (greywacke,
greywacke-slate and limestone), but comprising the
earliest mechanical depositions, and indicating the
gradual lowering of the level of the universal ocean.
Still newer, and occupying, on the whole, lower posi-
tions, marking the continued retirement of the waters,
were the Floetz Rocks, composed partly of chemical,
but chiefly of mechanical sediments, and including
sandstone, limestone, gypsum, rock-salt, coal, basalt,
obsidian, porphyry, and other rocks. Latest of all
His theoretical conceptions 215
came the Alluvial series, consisting of recent loams,
clays, sands, gravels, sinters, and peat.
This system was not put forward tentatively as
a suggestion towards a better comprehension of the
history of the earth. It was announced dogmatically
as a body of ascertained truth, about which there could
be no further doubt or dispute. Let me quote by
way of illustration a few sentences from Werner's
'Theory of Veins, where he definitely expresses his
opinions on these matters. " In recapitulating the
state of our present knowledge," he observes, " it is
obvious that we know with certainty that the floetz
and primitive mountains have been produced by a
series of precipitations and depositions formed in suc-
cession from water which covered the globe. We
are also certain that the fossils which constitute the
beds and strata of mountains were dissolved in this
universal water and were precipitated from it ; conse-
quently the metals and minerals found in primitive
rocks, and in the beds of floetz mountains, were also
contained in this universal solvent, and were formed
from it by precipitation. We are still further certain
that at different periods, different fossils have been
formed from it, at one time earthy, at another metallic
minerals, at a third time some other fossils. We
know, too, from the position of these fossils, one
above another, to determine with the utmost precision
which are the oldest, and which the newest precipitates.
We are also convinced that the solid mass of our globe
has been produced by a series of precipitations formed
in succession (in the humid way) ; that the pressure
of the materials, thus accumulated, was not the same
2 1 6 IVerner
throughout the whole ; and that this difference of
pressure and several other concurring causes have
produced rents in the substance of the earth, chiefly
in the most elevated parts of its surface. We are
also persuaded that the precipitates taking place from
the universal water must have entered into the open
fissures which the water covered. We know, more-
over, for certain, that veins bear all the marks of
fissures formed at different times ; and, by the causes
which have been assigned for their formation, that
the mass of veins is absolutely of the same nature as
the beds and strata of mountains, and that the nature
of the masses differs only according to the locality of
the cavity where they occur. In fact, the solution
contained in its great reservoir (that excavation which
held the universal water) was necessarily subjected to
a variety of motion, whilst that part of it which was
confined to the fissures was undisturbed, and deposited
in a state of tranquillity its precipitate." 1
It would be difficult to cite from any other modern
scientific treatise a series of consecutive sentences
containing a larger number of dogmatic assertions, of
which almost every one is contradicted by the most
elementary facts of observation. The habit of confi-
dent affirmation seems to have blinded Werner to
the palpable absurdity of some of his statements.
When, for example, he speaks of the great reservoir
or excavation which held the universal water, what
idea could have been present to his mind ? If the
primeval ocean, as he asserted, surrounded the whole
1 Neue Theorle von der Entstehung der G'dngen, chap. vii. 68 (1791).
English translation by Anderson, p. no (1809).
His Theory of a Universal Ocean 217
globe, and was as deep as the mountains are high,
where was the excavation ? As an acute writer in the
Edinburgh Review pointed out, the excavation spoken
of by Werner " can mean nothing else than the
convexity of the solid nucleus round which the
universal water was diffused. To call this convexity
an excavation, is to use such a freedom with language
as can only be accounted for by the perplexity in
which every man, of whatever talents, must find him-
self involved when he attempts to describe a whole,
of which the parts are inconsistent with one another." 1
The theory of a primeval universal ocean that over-
topped the mountains, which formed the basis of
Werner's teaching, led in every direction to such
manifest contradictions and absurdities, that we need
a little patience and some imagination to picture to
ourselves how it could have been received and fervently
believed in by men of intelligence, to whom the facts
of the earth's structure were not wholly unknown.
It was claimed for Werner that the doctrine of a
universal and gradually subsiding ocean, though it
had been taught long before his time, was first demon-
strated by him to be true, (i) because he found the
older strata occupying the highest eminences, and the
younger coming in at successively lower levels, down
to the modern alluvia of the plains and the sea-shore, 2
and (2) because the primitive and loftiest rocks are
entirely formed of chemical precipitations, those of
1 Edtn. Review, xviii. p. 90 (1811).
2 But as has been shown in a previous chapter, this idea had been
clearly enunciated long before by Buffbn and was recognized by
Werner's German predecessors.
2 1 8 IVerner
mechanical origin not appearing until a much later
period, and becoming increasingly abundant down to
the present time, when they constitute almost all the
deposits that are now taking place. 1
One of the most obvious questions that would arise,
we might suppose, in the mind of any student of
ordinary capacity to whom the theory was propounded,
would be how did the deep primitive ocean disappear.
Steno, Leibnitz, and other older writers had conjectured
that the waters found their way into vast caverns in
the earth's interior. Such a conjecture, however, was
not suited to the taste of the true Wernerian, who
would allow no speculation, but took his stand on a
basis of ascertained fact. Well, we may be curious to
know how he disposed of the difficulty. Yet we
shall search in vain through Wernerian literature for
any serious grappling with this obvious, and one
would have thought formidable, objection to the
doctrine. Werner himself appears to have inclined
to the belief that the waters vanished into space. He
thought it possible that " one of the celestial bodies
which sometimes approach near to the earth may
have been able to withdraw a portion of our atmos-
phere and of our ocean."' But if once the waters
were abstracted, how were they to be brought back
again, so as to cover all the hills on which his highest
Floetz formations were deposited ?
1 Jameson's Geognosy, p. 78. Werner's followers, from the promi-
nence they gave to the sea in their geognosy, were styled Neptunists,
while those of Hutton, who dwelt on the potency of the earth's
internal fire, were dubbed Plutonists or Vulcanists.
2 See D'Aubuisson's Geognosie, i. p. 414 (1819).
Diminution of his Universal Ocean 219
The most famous of the English followers of
Werner, Jameson, honestly asked the question, "What
has become of the immense volume of water that once
covered and stood so high over the whole earth ? "
His answer may be cited as thoroughly characteristic
of the mental attitude of a staunch Wernerian. " Al-
though," he says, " we cannot give any very satis-
factory answer to this question, it is evident that the
theory of the diminution of the water remains equally
probable. We may be fully convinced of its truth,
and are so, although we may not be able to explain
it. To know from observation that a great pheno-
menon took place, is a very different thing from
ascertaining how it happened." 1 I do not suppose that
in the whole literature of science a better illustration
could be found of the advice " When you meet with
an insuperable difficulty, look it steadfastly in the face
and pass on."
One might have thought that having disposed of
the universal ocean, even in this rather peremptory
fashion, the Wernerians would have been in no hurry
to call it back again, and set the same stupendous
and inexplicable machinery once more going. But
the exigencies of their theory left them no choice.
Having determined, as an incontrovertible fact, that
certain rocks had been deposited as chemical precipitates
in a definite order from a universal ocean, when these
philosophers, as their knowledge of Nature increased,
found that some of these so-called precipitates occurred
out of their due sequence and at much higher altitudes
than had been supposed, they were compelled to bring
1 Jameson, op. at. p. 82.
220 Werner
back the universal ocean, and make it rise high over
hills from which it had already receded. Not only
had they to call up the vasty deep, but they had to
endow it with rapid and even tumultuous movement,
as it swept upwards over forest-clothed lands. Having
raised it as high as their so-called Floetz formations
extended, and having allowed its waters to settle and
deposit precipitates of basalt and greenstone, they had
to hurry it away again to the unknown regions where
it still remains. This, forsooth, was the system that
discarded hypothesis, and rested proudly on an irre-
fragable foundation of demonstrable fact.
In another notable respect the crudeness of the
Wernerian sytem and its disregard of the most familiar
facts in nature are shown by its classification of so
many diverse kinds of rocks as chemical precipitates
from a hypothetical universal ocean. Chemistry was
then sufficiently far advanced to prove the absurdity
of this dogma. Even if the ocean had been a mass
of boiling water, it could not have held all these rocks
in solution, and have deposited them as successive
precipitates. But the Wernerian geognosts scouted
the idea that the globe and its outer envelopes, ever
had a high temperature. They seem never to have
tried to reason out the chemical reactions involved
in their theory of solution and precipitation, nor to
have formed any conception of the causes which could
have led to the successive deposition of the various
precipitates. That the ocean could not have been a
strong solution of mineral substances when the so-
called chemical precipitates of the Transition Rocks
were deposited, but must have had a composition
His explanation of Basalt 221
not greatly dissimilar to what it possesses now might
have been suggested to these theorists by the occur-
rence of the abundant remains of animal life in many
of the rocks a fact of which they ultimately became
well aware.
A further singular characteristic of the Wernerian
school was the position it took up with regard to the
evidence for disturbances of the earth's crust, and for
the universality and potency of what is now termed
igneous action. A hundred years before Werner's
time Steno had pointed to the inclined and broken
strata of Northern Italy as evidence of dislocation of
the crust. The Italian observers, and especially Moro,
familiar with the phenomena of earthquakes and vol-
canoes, had been impressed by the manifest proofs
of the potency of the internal energy of the earth
upon its outer form. But these early adumbrations
of the truth were all brushed aside by the oracle of
Freiberg. I have tried to imagine the current of
thought by which Werner was led to this crowning
absurdity of his system, and I think we may trace it
in the history of his relation to the basalt hills of
Saxony. The question is of some interest, not only
as a curious piece of human psychology, but because
it was on this very point of the origin of basalt that
the Wernerian ship finally struck and foundered.
The year after his appointment as teacher of
mineralogy, Werner visited the famous Stolpen, one
of the most picturesque castle-crowned basalt hills
of Saxony, to which I have already referred in con-
nection with Agricola's revival of the old word
" basalt." He had probably by this time begun to
222 Werner
form in his mind a more or less definite picture
of chemical precipitation from aqueous solution, as
applied to the history of rock-masses. But be this
as it may, he was aware that basalt, by not a few
observers before his time, had been claimed as a
rock of volcanic origin. How far he had then
made up his mind as to the formation of that rock
must remain in doubt. But he tells us himself that
at the Stolpen he " found not a trace of volcanic
action, nor the smallest proof of volcanic origin. So
I ventured publicly to assert and prove that all basalts
could certainly not be of volcanic origin, and that to
these non-volcanic rocks the Stolpen mass undoubtedly
belongs. Though at first I met with much opposi-
tion, yet soon several geognosts came over to my
views. These views gained special importance from
the observations which I made in 1777 on the old
subterranean fire in the coal-field that lies around
the hills of basalt and porphyry-slate in the middle of
Bohemia, and the consequent pseudo-volcanic hills that
have arisen there. After further more matured re-
search and consideration, I hold that no basalt is
volcanic, but that all these rocks, as well as the other
Primitive and Floetz rocks, are of aqueous origin." l
1 Kurze Klassifcation und Beschreibung der Verschledenen Gebirgsarten,
1787, p. 25. Later in the same year (1787) he visited a little
eminence near Scheibenberg in the Erzgebirge, and found there
a cake of basalt lying on clay and sand, and thought he could trace
these materials passing into each other. Whereupon he announced
as a " new discovery " that all basalt is of aqueous origin, and
constitutes, with clay, sand and wacke, one single formation which
originally extended far and wide over the primitive and floetz
rocks, but has in course of time been worn away, leaving only
cappings on the hills. Keferstein, Geschlchte der Geognosie, p. 69.
The Basalt Controversy 223
Thus ten years of reflection had only served to
make him more positive in maintaining an opinion
which the most ordinary observation in his own
Saxony ought to have enabled him to disprove and
reject. He had not only asserted that basalt is a
chemical precipitate, but had placed it among his
primitive rocks.
When we remember the long and patient labours
of Desmarest before he announced his conclusions
regarding the volcanic origin of basalt, we cannot
but wonder at the audacity of Werner in discarding
these conclusions without comment, and announcing
an entirely opposite opinion, rapidly formed on the
slender evidence of one or two isolated patches of
basalt. It was not as if he claimed to apply his
explanation merely to those few cases which he had
himself examined ; he swept all the basalts of the
earth's surface into his net. His view had not even
the merit of originality, for, as we have seen, Guet-
tard, among others, had held the opinion that basalt
is of aqueous origin. But, announced as a new dis-
covery, with all the authority of the great Freiberg
professor, it commanded attention and met with wide
acceptance. Even from the time of its promulgation,
however, it awakened some opposition, and it became
the subject of bitter controversy for fully a generation.
Only a month after Werner proclaimed his discovery
he was answered by J. K. W. Voigt of Weimar, who
maintained the volcanic nature of the very examples
cited by the professor. 1 Werner replied, and was
l Bergmann. Journ. 1788, 1789, 1791, pp. 185, 347, etc. See
also Hoffmann's Geschichte der Geognos'r (1838), p. 117.
224 Werner
again answered, but soon retired from the combat and
devoted his energies to strengthen his theory. As an
instance of the wide interest taken in the question,
I may mention that even at Berne, where there are
no basalts, nor any other traces of volcanic action,
the Society of Naturalists of that town offered a prize
of twenty-five thalers for the best essay in answer to
the question, " What is Basalt : Is it volcanic or is
it not ? " The successful competitor, after elaborately
reviewing all the arguments brought forward by the
Vulcanists, pronounced in favour of Werner's views. 1
Werner himself made two contributions to the dis-
cussion, one giving his theory of volcanoes, 2 and the
other his matured views upon basalt. 3
Volcanoes and volcanic action, if they were regarded
as betokening any potent kind of reaction between
the interior and the exterior of our planet, were utterly
antagonistic to Werner's conception of the structure
and history of the earth. In a world which had
entirely resulted from the precipitations and depositions
of an ocean of water, there was obviously no place for
internal fire. In the system which Werner had so
laboriously devised, it was imperatively necessary to
treat volcanoes as modern and accidental phenomena,
which never entered into the process of the formation
of the crust of the earth. Accordingly, in his earliest
sketch of his classification of rocks, he placed volcanic
rocks among the latest of the whole series. And this
1 J. F. W. Widenmann, Hopfner's Magazin fiir die Erdkunde, iv.
(1789), p. 135.
2 Hopfner's Magazin fur die Erdkunde, iv. (1789), p. 239.
9 Bergmdnnisches Journal, 1789, i. p. 252. See also p. 272.
Werner on Volcanoes 225
view he maintained to the last. That volcanic action
had been in progress from the very beginning of
geological time, and that it had played an important
part in building up the framework of the land in
many countries all over the globe, were ideas that
seem never to have occurred to him.
We have seen how old was the notion that vol-
canoes, or " burning mountains/' arose from the
combustion of subterranean beds of coal. Werner
adopted this opinion, which suited his system, and
was quite in congenial surroundings there. In 1789,
two years after the appearance of his little Kurze
Klassification, he definitely announced, in one of the
papers above referred to, what he called the " highly
probable conjecture that most, if not all, volcanoes
arise from the combustion of underground seams of
coal." * The coal might be set on fire by spontaneous
combustion, and the most vigorous volcanoes would
be those starting on the thickest masses of coal. In
order to support this belief, it was necessary to furnish
evidence of the existence of deposits of coal around
volcanoes. And much research and ingenuity were
displayed in collecting all the known examples. Not
only coal, but every kind of natural inflammable sub-
stance was pressed into service, and made to do duty
as fuel for the subterranean fires.
It was also obviously needful to maintain that vol-
canoes must be comparatively modern phenomena.
We are told that " it was only after the deposition
of the immense repositories of inflammable matter
in the Floetz-trap that volcanoes could take place ;
1 See the paper just cited in Hopfner's Magaz. iv. (1789), 240.
P
226 Werner on Basalt and Lava
they are therefore to be considered as new occurrences
in the history of Nature. The volcanic state appears
to be foreign to the earth." x
The similarity of basalt to many undoubtedly vol-
canic rocks had long been noticed, and could not
escape the observant eyes of Werner. But he did
not therefore infer basalt to be of volcanic origin.
He had already established, as one of the indisputable
canons of geognosy, that basalt was precipitated from
chemical solution in a universal ocean. The way
in which he accounted for the resemblance between
basalt and lava must be regarded as a signal proof of
his ingenuity. He announced that volcanoes not
only occur where there are seams of coal, but where
these are covered by sheets of basalt and wacke, and
that eruptions of lava take place when these overlying
rocks are melted by the combustion of the coal. He
thus provided himself with a triumphant answer to any
objector who felt inclined to question his dictum as to
the origin of basalt. If the rock occurred on isolated
hill tops, it was a member of the Floetz-trap formation
produced by universal chemical precipitation. If it
was found in the condition of lava, the original precipi-
tate had been fused by the burning of underlying
seams of coal.
With so flexible a theory to defend and apply, it can
be understood how the pupils of the Freiberg school
scouted the notion that volcanoes were of any real
geognostical importance, and how they had a ready
1 Jameson's Geognosy, p. 96. Werner could not claim even
originality for this absurd doctrine, for it had been adopted by
Buffon before the Saxon professor was born (ante, p. 93).
Wernerian Volcanic Theory 227
answer to any opponent, or a prompt explanation
of any apparent difficulty in the acceptance of their
master's teaching. If any one claimed that basalt was
of volcanic origin, he was at once confidently assured
that this was an entire mistake, for the great law-giver
of Freiberg had pronounced it to be a chemical precipi-
tate from water. If he ventured to quote the columnar
structure as in favour of his view, he was told that
he ought to know that lava never assumed this
structure, 1 and that " rocks which have been formed
or altered by the action of heat are most distinctly
different from those that constitute the great mass
of the crust of the globe." 2 If he brought to the
unabashed Wernerian a piece of obsidian, and asked
whether such a rock should not be admitted to be
a volcanic glass, " Nothing of the kind," would have
been, in effect, the immediate reply. " It is true that
the rock does resemble c completely melted stony sub-
stances, and occurs in volcanic countries/ but the
notion that it is itself of volcanic origin is quite
unfounded, ( because obsidian has never been observed
accompanying lava, because it is connected with basalt,
and because it contains a considerable portion of water
of composition, which is never the case with true
volcanic rocks/" 3 If the questioner, still unconvinced,
presumed to present a piece of pumice, pointing to its
froth-like structure and its presence in volcanic coun-
tries as evidence of its former fusion, the answer would
have been an equally prompt and decided negative.
Let me quote the actual words of a Wernerian in
1 Jameson, op. cit. p. 58. 2 O/. cit. p. 74.
3 Op. cit. p. 1 96.
228 Werner on disturbances of earth's crust
reply. " It was formerly the general opinion that
pumice was a volcanic product, because it frequently
occurs in countries conjectured to be of igneous forma-
tion. It is now ascertained to be an aquatic product,
from the following facts : i, It alternates with Nep-
tunian rocks, as basalt and porphyry ; 2, it is most
distinctly stratified ; 3, it passes into obsidian and
pearlstone, and is thus connected with basalt, pitch-
stone, etc. ; 4, it contains water of composition, which
is never the case with true volcanic rocks ; 5, it has
never been observed to flow in streams from the crater
or sides of a volcano, and no one ever saw it forming
a stream in countries containing extinct volcanoes." 1
Well might the inquirer retire in despair from such
an encounter. In vain would he have sought an
explanation of the origin of the vesicular structure of
the rock, or have asked how this structure could ever
have originated from an aqueous solution. He would
probably have been plied with a few more " facts " of
equal veracity, and a few more examples of reasoning
in a circle. But he would never succeed in extracting
an expression of doubt, or an admission that the ipse
dimt of the Freiberg professor could for a moment be
called in question.
The same attitude which Werner assumed towards
volcanoes was consistently maintained by him in his
treatment of the proofs of disturbances in the terrestrial
crust. He seems never to have realized that any reser-
voir of energy is stored up in the interior of our globe.
It was part of his teaching that the spheroidal form of
the planet furnished one of the proofs of a primeval
1 Jameson, op. cit. p. 196.
IVerner on Mineral Veins 229
universal ocean. He admitted that the crust had been
abundantly cracked, but in these cracks he saw no
evidence of any subterranean action. His own state-
ment of his views on this subject is sufficiently explicit,
and I quote his words : " When the mass of materials
of which the rocks were formed by precipitation in the
humid way, and which was at first soft and movable,
began to sink and dry, fissures must of necessity have
been formed, chiefly in those places where the greatest
quantity of matter has been heaped up, or where the
accumulation of it has formed those elevations which
are called mountains." 1 He gave no explanation of
the reason why the precipitates of his universal ocean
should have gathered more thickly on one part of the
bottom than on another. It was enough for himself
and his disciples that he was convinced of the fact.
As all rents in the earth's crust were thus mere
superficial phenomena resulting from desiccation and
the slipping down of material from the sides of moun-
tains, so it was conceived by Werner that, when they
were filled up, the mineral matter that was introduced
into them could only come from above. He drew no
distinction in this respect between what are now called
<c mineral veins " and " intrusive veins." Veins of
granite, of basalt, of porphyry, of quartz, of galena, or
of pyrites were all equally chemical precipitates from an
overlying sea. He does not appear to have seen any
difficulty in understanding how the desiccation and
rupture of the rocks were to take place, if the sea still
covered them, or how, if they were exposed to the air
and evaporation, he was to raise the level of the ocean
1 Theory of Veins, 39.
230 Werner's Classification of Rocks
again so as to cover them, and fill up their rents with
new precipitates.
Werner's original scheme of classification of the
rocks of the earth's crust had at least the merit of
clearness and simplicity. Though he borrowed his
order of sequence partly from Lehmann and Fiichsel,
he worked it into a scheme of his own regarding the
origin of the rocks and their successive production
from a universal ocean. Tracing in the arrangement
of the rocks of the earth's crust the history of an
original oceanic envelope, finding in the masses of
granite, gneiss, and mica-schist the earliest precipita-
tions from that ocean, and recognising the successive
alterations in the constitution of the water as witnessed
by the series of geological formations, Werner launched
upon the world a bold conception which might well
fascinate many a listener to whom the laws of chemistry
and physics, even as then understood, were but little
known. Unfortunately the conception was based en-
tirely on the imagination, and had no real foundation
in observation or experiment.
Werner adopted the leading ideas of his system in
an early part of his career when his personal experience
was extremely limited. And having once adopted
them, he maintained them to the last. His methodical
mind demanded some hypothesis that would allow him
to group, in definite and genetic connection, all the
facts then known regarding the structure of the earth's
crust. His first sketch of a classification of rocks
shows by its meagreness how slender at that time
was his practical acquaintance with rocks in the field.
The whole of the Primitive formations enumerated
chronological method 231
by him are only twelve in number, and some of these
were confessedly rare. As years went on, he inter-
calated new varieties, introduced the division of
Transition rocks, and was compelled to reduplicate
some of his primitive formations by having to find
places also for them among the Floetz series.
Yet with all these shiftings to and fro, the apparent
symmetry and conspicuous method of the system were
retained to the end. No Saxon mine could have had
its successive levels more regularly planned and driven,
than the crust of the earth was parcelled out among
the various Wernerian universal formations. Each of
these had its definite chronological place. When you
stood on granite, you knew you were at the base
and root of all things mundane. When you looked
on a hill of Floetz-trap you saw before you a relic
of one of the last acts of precipitation of the ancient
universal ocean.
But Nature has not arranged her materials with the
artificial and doctrinaire precision of a mineralogical
cabinet. Werner's system might temporarily suffice
for the little part of the little kingdom of Saxony
which, when he promulgated his views, he had im-
perfectly explored. But as his experience widened
and new facts accumulated, the modifications to which
I have referred were so serious that they might well
make the author of the system pause, and raise in his
mind some doubts whether the fundamental conception
on which the system was based could possibly be true. 1
1 D'Aubuisson, a loyal and favoured pupil of the Saxon Professor,
remarks that "Werner has continued from year to year to modify,
and even to recast, some parts of his doctrine, while his disciples,
232 Artificiality of JVerne^s system
It was eventually found, for instance, that some granite
overlies instead of underlying the slates of the Primitive
series ; that some greenstones, instead of occurring
among the Primitive rocks, lie in the Floetz division ;
that there are ever so many horizons for porphyry,
which was at first believed to be entirely Primitive.
These contradictions were surmounted by affixing such
adjectives as " oldest " or " newest " to the several
appearances of the same rock, or by numbering them
according to their various horizons. Thus there were
oldest and newest granites, oldest and newer serpen-
tine, and first, second, and third porphyry formations.
This patching up of the system may have saved it
in appearance, but a moment's reflection will show us
that it was fatal to Werner's fundamental doctrine of
a series of successive chemical precipitates from a uni-
versal ocean, which by the deposition of these precipi-
tates was gradually altering its constitution. The
modifications rendered necessary by fresh discovery
proved that the supposed definite sequence did not
exist. In fact, as was well said by a critic at the
time, they were mere u subterfuges by which the
force of facts was evaded." 1 They were devised for
the purpose of bolstering up a system which was
entirely artificial, and to the erroneousness of which
new facts were continually bearing witness.
It was claimed for Werner that he first established
the doctrine of geological succession in the earth's
following his teaching, in proportion as their observations have
multiplied, have added, and are continually adding new improve-
ments to his system." Traite de Geognosle (1819), preface, p. xvi.
^Edinburgh Review, vol. xviii. (1811), p. 95.
Werners lectures 233
crust. We have seen that the idea was already
supplied to him by Lehmann and Fttchsel, and it is
now evident that, by working into it his notion of
universal aqueous precipitates, he introduced an element
of hypothesis which threw back for some years the
progress of sound geology. What was true in the
doctrine was borrowed from his predecessors, what
was his own consisted largely of unwarranted assump-
tion. He undoubtedly did enormous service by his
precise definitions and descriptions of rocks, and by
dwelling on the fact that there was an observable
order of succession among them, even though he
mistook this order in some important particulars, and
entirely misinterpreted its meaning and history. The
full significance of geological succession was not under-
stood until it was worked out independently in Eng-
land and France by a rigid collection of facts and on
a palaeontological basis, as I shall describe in a later
chapter.
Werner's writings are so few and slight that his
disciples and admirers continually expressed their
sorrow that he would leave so little behind him
save his world-wide fame. His natural dislike of the
pen increased with his years. He would discourse
eloquently on many subjects, but could never bring
himself to write fully on any one. Usually when he
went to lecture he would retire for a quarter of an
hour to arrange his ideas, and when he appeared before
his audience he brought with him only some scraps of
paper, with a few words scribbled on them. He never
wrote a single lecture. If this abstinence from the
use of the pen saved him from scientific controversy
234 Werner's aversion to writing
it did not secure him undisturbed repose. With all
his efforts after the placid life of a philosopher, there
was one subject that not unnaturally stirred his wrath
the unwarranted publication, or at least circulation of
his lectures and theories. As he did not publish them
himself, and as there was a widespread desire to become
acquainted with them, manuscript copies of notes of his
lectures were widely circulated, as a kind of mercan-
tile speculation. This was bad enough, but he heard
of an intention to print and publish them. So he
took an opportunity of cautioning the world that,
while willing to shut his eyes on the past, he could
not tolerate any such conduct in future, that he was
himself engaged in revising his works on the several
branches of science he professed, and that they would
" forthwith appear one after another, enriched by his
latest observations and discoveries." l But the revi-
sion was never made, and the publications never
appeared.
Werner's repugnance to writing in any form increased
with his years. By degrees he ceased to write letters,
even when the dearest friend begged for a reply, and
at last, to save himself from the reproach of this
neglect, he allowed the letters which he received to
remain unopened. Cuvier tells how once an author,
desiring to consult some of the learned men of the day
concerning a work which he proposed to publish, circu-
lated his voluminous manuscript among them. The
precious parcel disappeared in the circuit. After end-
less seeking, it was disinterred in Werner's room from
underneath some hundreds of others. He never
1 New Theory of the Formation of Veins , 1791, preface.
Characteristics of Werner 235
answered the Academy of Sciences of Paris when it
conferred on him the very high distinction of electing
him one of its eight foreign associates, and he might
never have heard of the affair had he not come across
the mention of it in some almanack. " But," says
Cuvier, " we forgave him when we heard that about
the same time a messenger sent express by his sister
from Dresden had been kept waiting, at the professor's
expense, for two months for a mere signature to some
pressing family document."
Save for the occasional irritation caused by rumours
of the unwarranted reproduction of his lectures, Wer-
ner's life appears to have passed quietly in the midst of
the work which he loved and the pupils and friends
who looked up to him with veneration and affection.
His health was never robust, and the effort of lecturing
proved sometimes a great strain upon his energy.
After a discourse in which he would pour forth his
ideas with the full flow of his exuberance, the bodily
and mental effort would be so great that he would
have to change his clothes even to his inner raiment.
He tried to preserve both body and mind in an equable
frame. Among his little foibles was the care he took
never to expose himself to a draught. He kept him-
self out of controversy, and eventually refrained even
from reading the journals, and from knowing what was
said in the outer world about himself and his opinions.
In this tranquil life he might perhaps have prolonged
his days, had not his feelings been deeply stirred by the
misfortunes which, during the Napoleonic wars, had
befallen Saxony, his adopted home. He took these
trials so much to heart that they led to a series of
236 Characteristics of IVerner
internal complications, from which he died at Dresden,
in the arms of his sister, on 3Oth June 1817, in the
sixty-eighth year of his age.
Whether the regrets loudly expressed by his con-
temporaries that Werner published so little were justi-
fied, may perhaps be open to doubt. If his fame had
to rest on his written works, or even on his teaching as
expounded by his pupils, it could never have grown so
great, nor, judging from what we know of his views in
maturer life, can we suppose that any account of them
by himself would really have added to his reputation,
or have contributed materially to the advancement of
science. It was not his writings, nor even his opinions
and theories in themselves, that gave him his unques-
tioned authority among the geologists of his time.
His influence and fame sprang mainly from the
personality of the man. His unwearied enthusiasm
and eager zeal in the furtherance of his favourite
studies, his kindness and helpfulness, his wide range
of knowledge, and the vivacity, perspicuity, and
eloquence with which he communicated it, his abso-
lute confidence in the solidity of his theoretical
doctrines these were the sources of his power rather
than the originality and importance of his own contri-
butions to geology. His followers, indeed, captivated
by the precision of his system and its apparent applica-
bility in any and every country, claimed for him the
highest place in the ranks of those who had studied the
history of the earth. But the exaggeration of their
claim was amply shown by the rapidity with which
the Wernerian doctrines began to fall into disrepute
even before the death of their author.
CHAPTER VIII
THE Wernerian School of Geology, Its great initial influence and
subsequent decline. Effect of the controversy about the origin
of Basalt upon this School. Early history of Volcanic Geology.
History of opinion regarding Earthquakes.
IN tracing the influence of Werner's teaching upon the
progress of geological inquiry, we must begin by the
full and frank acknowledgment that when all objec-
tions and qualifications have been made regarding his
theoretical opinions, the momentous fact remains that
by his personal example and contagious enthusiasm
he rendered a vast service to the science. He
awakened a far more widespread interest in the
ancient history of the earth than had ever before
existed, and even where his pupils found reason
eventually to abandon many of the doctrines which
he had taught them, they still retained their devotion
to the studies for which he had kindled in them so
ardent a zeal. " It was to his irresistible influence,"
as Cuvier has well remarked, " that the world owes
those authors who have treated so fully of minerals,
and those indefatigable observers who have so fully
explored the globe. The Karstens and the Wiede-
manns in the cabinet, the Humboldts, the Von Buchs,
238 Influence of Werner on Petrography
the D'Aubuissons, the Hermanns, the Freieslebens,
at the summit of the Cordilleras, in the midst of
the flames of Vesuvius and of Etna, in the deserts
of Siberia, in the depths of the mines of Saxony, of
Hungary, of Mexico, of Potosi, have been borne on-
ward by the spirit of their master ; they have brought
back to him the honour gained by their labours ; and
we may say of him, what was never truthfully said
before, save of Linnaeus, that Nature everywhere
found herself interrogated in his name."
Besides this general impetus to the pursuit of
geology, Werner left on the science of his time and
country that bias towards the mineralogical and petro-
graphical side which has ever since so honourably
distinguished German geological investigation, and
which in our own day has culminated in the master-
pieces of Roth, Groth, Zirkel, Rosenbusch, and many
other notable writers. Again, his constant advocacy
of the doctrine of geological succession kept the
interest and importance of the problem before the
world, and helped to prepare the way for the great
advances which have since been made in that depart-
ment of the science. But his theoretical views on
this subject, and the comparative neglect of organic
remains in his system, tended to retard in his own
country the fuller development of stratigraphy, which
was making even during his lifetime such rapid
strides in England and France.
As it was the exigencies of Saxon mining industry
that started the Mining School of Freiberg, so the
teaching there had necessarily constant reference to
the underground operations of the district. Much of
Characteristics of Werner's Teaching 239
Werner's practical acquaintance with the relations and
structure of rock-masses was derived from what he
learnt at the mines. It was only natural, therefore,
that he should have inculcated upon his pupils the vast
importance of subterranean exploration in unravelling
the structure of the earth. The devout Wernerian
put mines before mountains as a field for geological
investigation. 1 Indeed the whole system of the Frei-
berg school, with its limited knowledge, its partial view
of things, its dogmatism and its bondage to precon-
ceived theory, is suggestive rather of the dim lamplight
and confined outlook of a mine than of constant and
unfettered contact with the fresh and open face of
Nature.
These characteristics of Werner's teaching were
keenly felt by some of the more clear-sighted of his
contemporaries, who, though they recognised his
genius and the vast services he had rendered to
mineralogy by solid achievement, as well as by the
enthusiasm he had excited in many hundreds of pupils,
yet felt that in regard to geological progress his influ-
ence had become retrogressive and obstructive. This
judgment was forcibly expressed in the article which
appeared in the Edinburgh Review in the year 1 8 1 1
from which some citations have been given in the fore-
going pages. I have reason to believe that this article
was from the pen of Dr. W. H. Fitton, who after-
wards became one of the leaders of English geology.
A few sentences from it may here be quoted.
"The Wernerian school obstructs the progress of
discovery. The manner in which it does so is plain.
1 See, for example, Jameson, op. clt. p. 43.
240 The IVernerian Geognosy
By supposing the order already fixed and determined
when it is really not, further inquiry is prevented, and
propositions are taken for granted on the strength of a
theoretical principle, that require to be ascertained by
actual observation. It has happened to the Wernerian
system, as it has to many other improvements ; they
were at first inventions of great utility ; but being
carried beyond the point to which truth and matter
of fact could bear them out, they have become obstruc-
tions to all further advancement, and have ended with
retarding the progress which they began with accelerat-
ing. This is so much the case in the instance before
us, that when a Wernerian geognost, at present, enters
on the examination of a country, he is chiefly employed
in placing the phenomena he observes in the situations
which his master has assigned to them in his plan of
the mineral kingdom. It is not so much to describe
the strata as they are, and to compare them with rocks
of the same character in other countries, as to decide
whether they belong to this or that series of deposi-
tions, supposed once to have taken place over the
whole earth ; whether, for example, they be of the
Independent Coal or the Newest Floetz-trap forma-
tion, or such like. Thus it is to ascertain their place in
an ideal world, or in that list of successive formations
which have nothing but the most hypothetical exist-
ence : it is to this object, unfortunately for true
science, that the business of mineralogical observation
has of late been reduced." x
So long as the great master at Freiberg lived, the
loyalty of his attached pupils naturally kept them
ln. Review, vol. xviii. (1811), art. 3, pp. 96, 97.
J. F. D'Aubuisson 241
from openly rejecting his doctrines, even when they
could no longer accept them. His death in 1817
was felt by many of them to bring a relief from the
despotism which he had so long exercised. 1 And
from that time his system declined in favour even in
Germany.
It was one of the most singular episodes in the his-
tory of geological science that the first serious check
to the triumphal march of Wernerianism through
Europe came from two of Werner's most distin-
guished pupils, D'Aubuisson and Von Buch, and that
their first opposition to their master's teaching was
inspired by that very volcanic tract in Central France
to which Desmarest had so long before appealed in
vain. Let us see how, in this instance, the whirligig
of time brought in his revenges.
Jean Francois D'Aubuisson de Voisins (1769-1819)
was born in the south of France on i6th April, 1769.
After receiving his early education in his own country,
he spent some years as a diligent student at the Mining
School of Freiberg. For four consecutive years, he
tells us, he was in the most favourable circumstances
for mastering the Wernerian doctrines, inasmuch as
the illustrious teacher honoured him with particular
attention, and in the course of many conversations
unfolded to him the principles of his science, and
traced for him the path that would lead him to the
1 One of Jameson's ablest pupils, Ami Boue, trained in the Wer-
nerian faith, confessed, but with evident reluctance, and " as a truth
which others may be unwilling to make public," that Werner's death
had greatly contributed to the progress of geology in Germany.
Journ. Phys. xciv. (1822), p. 298.
Q
242 D'Aubuisson on Basalt
establishment of a true geognosy. 1 While still pur-
suing his studies in Saxony, D'Aubuisson took up
the question of the basalts of that kingdom, travelled
over all their scattered hills, and at last wrote a treatise
upon them, which appeared in Paris in 1803. In this
little volume of 170 pages the Wernerian doctrine as
to the origin of basalt is not only accepted but treated
as if it were incontestable. In one passage, indeed, the
author guards himself by saying that his conclusions
have reference only to the basalts which he himself
has seen, and that if some day he can visit Auvergne
and the Vivarais, he perhaps may be better able to
discuss the question more generally, and to appreciate
what has been written on the other side. 2 His essay
was presented to the Institute of Sciences, and the two
referees, Hatty and Ramond, to whom it was submitted,
appended to their favourable report on it a most
judicious piece of advice to the young author. <C A
subject," they say, " where the analogies already
hazarded have led to more than one mistake, de-
mands the utmost caution in their use, and in a field
which the two parties dispute foot by foot, every step
should be justified by an observation and marked by
a fact. Citizen D'Aubuisson has never seen either
active or extinct volcanoes. Living till now in the
midst of aqueous formations, we should like him to
visit places where fire has manifested its empire. We
would especially desire that he should see the basalts of
Auvergne, which another disciple of Werner [Leopold
1 Traite de Geognosie (1819), vol. i. preface, p. xv.
2 Memoire sur les Basaltes de la Saxe, Paris, 1803, pp. 97, 100,
IOI.
D'Aubuisson in Auvergne 243
von Buch] has just visited. That the citizen D'Aubuis-
son knows how to observe, is shown by his published
works, even if the memoir we have now been consider-
ing were not ample enough proof, and the interest of
his observations cannot be recognised in a manner
more useful to science than by encouraging him to
continue them."
D'Aubuisson lost no time in following the advice
thus given to him. He went to Auvergne and
found the basaltic rocks there lying on granite,
which in some valleys could be seen to be more
than 1 200 feet thick. If these basaltic rocks were
lavas, they must, according to the Wernerian doc-
trine, have resulted from the combustion of beds of
coal. But how could coal be supposed to exist under
granite, which was the first chemical precipitate of a
primeval ocean ? Such an infra-position was incon-
ceivable, and thus an apparent confirmation of the
Freiberg view of the aqueous origin of basalt was
at first obtained. But a very short time sufficed to
stagger the young geologist. He saw the perfect
craters with their rugged lava-streams, which he
followed along their branches into the valleys. It
was impossible to resist this evidence. " The facts
which I saw," he says, " spoke too plainly to be
mistaken ; the truth revealed itself too clearly before
my eyes, so that I must either have absolutely refused
the testimony of my senses in not seeing the truth, or
that of my conscience in not straightway making it
known. There can be no question that basalts of
volcanic origin occur in Auvergne and the Vivarais.
There are found in Saxony, and in basaltic districts
244 D'Aubuissoris recantation
generally, masses of rock with an exactly similar
groundmass, which enclose exactly and exclusively
the same crystals, and which have exactly the same
structure in the field. There is not merely an
analogy, but a complete similarity ; and we cannot
escape from the conclusion that there has also been
an entire identity in formation and origin/' l
The frank and courageous Wernerian read his
recantation before the Institute of France the year
after his work on the Saxon basalts appeared. 2 Still
retaining his profound admiration for Werner, he
nevertheless relinquished one after another the peculiar
tenets of the Freiberg school, and became so impartial
a chronicler of geological progress, that in his remark-
ably able ^Treatise on Geognosy, though inclining, on the
whole, to his master's system, he did not entirely
l Geognosie, vol. ii. pp. 603, 605. Ch. Keferstein wrote a learned
disquisition on Basalt entitled " Beitrage zur Geschichte und
Kenntniss des Basaltes, und der ihm verwandten Massen," which
is contained in the Neue Schriften der Naturforschenden Gese Use haft
zu Halle, Band ii. 1819. The last part of the Memoir (pp. 139-
250) consists of a review of the various opinions which up to that
time had been expressed in regard to the nature of the rock, and
contains copious references to authorities.
2 " Sur les volcans et les basaltes de 1'Auvergne," read to the
Institute of Sciences in 1804 ; Journ. de Physique, torn. Iviii. p. 427,
lix. p. 367, Ixxxviii. (1819), p. 432 ; Soc. Philom. Bull. Paris, 1804,
p. 182. It is an indication of the slowness of the transmission of
scientific news in those days that in the English translation of
D'Aubuisson's Basalts of Saxony, which appeared at Edinburgh in
1814 that is, eleven years after the original the translator states
that he had heard of the author's having modified his views regarding
the basalts of Auvergne, but that he was not aware that he had
expressed any change of opinion in respect of those of Saxony.
Early career of L. Von Buck 245
adopt it, but presented his facts and inferences in
such a manner that, as he himself claimed, even a
follower of Hutton would hardly find a few para-
graphs which he would wish to modify. D'Aubuisson
lived into his seventy-third year, and died in 1819.
We turn now to the story of Leopold von Buch
(1774-1853), the most illustrious geologist that Ger-
many has produced. He came of a good family,
which as far back as the twelfth century held an
important position in the district of Altmark. His
father, an ambassador in the Prussian service, had a
family of six sons and seven daughters. Leopold, the
sixth son, born on 25th April 1774, passed through
a short course of mineralogical and chemical teaching
at Berlin, and then went to Freiberg at the age of
sixteen, to place himself under the guidance of Werner.
He lived mostly under that great teacher's roof for
three years, having for part of the time as his com-
panion Alexander von Humboldt, with whom he then
began a lifelong friendship. From Freiberg, where he
drew in the pure Wernerian inspiration, he proceeded
to the University of Halle, and later to that of
Gottingen. For a brief period he held an appoint-
ment in the mining department of Silesia, but he
soon abandoned the trammels of official employment,
and having a sufficient competence for life, dedicated
himself heart and soul to independent geological
research. He was by far the most eminent of all
the band of active propagandists who, issuing from
Freiberg, spread themselves over Europe to illu-
mine the benighted natives with the true light of
Wernerianism.
246 Von Buck's Early Writings and Travels
Von Buch's earlier writings were conceived after
the strictest rules of his master's system. In his first
separate work, a mineralogical description of Landeck,
he proclaimed, among other orthodox tenets of the
Freiberg school, his adhesion to the aqueous origin of
basalt, collected all the instances he could find of
organic remains in that rock, and boldly affirmed
that "it cannot be denied that Neptunism opens up
to the spirit of observation a far wider field than
does the volcanic theory." x
In the year 1797 Von Buch had his first view of
the Alps, and in the following year began his more
distant journeys, passing into Austria, and thence into
Italy, where he spent a considerable time among the
volcanic districts. In 1802 he published the first of
two volumes descriptive of these early travels. It was
appropriately dedicated to Werner, and expressed his
continued adhesion to the Wernerian faith. "Every
country and every district," he remarks, " where basalt
is found furnishes evidence directly opposed to all
idea that this remarkable rock has been erupted in a
molten condition, or still more that each basalt hill
marks the site of a volcano." 2 Before the second
volume appeared, the writer of that sentence had an
opportunity of visiting Auvergne. His conversion
there appears to have been as rapid as that of
1 Gesammelte Schriften, vol. i. p. 68.
2 Geognostische Eeobachtungen auf Reisen durch Deutschland und Italien,
Berlin, i. (1802), p. 126. It is a curious fact that A. von Humboldt
also began his geological career among the basalts of Germany, and
published in 1790 a little tract of 126 pages, entitled Mineralogische
Beobachtungen uber einige Basalte am Rhein.
Buck in Auvergne 247
D'Aubuisson, but his announcement of it was much
more sensational. It was in the spring of 1802 that
he went to Central France, but owing to various
accidents the second volume of his travels did not
appear until the year iSc^. 1 He had made no secret,
however, of his change of opinion, for in the winter
following his French tour, a letter from him was pub-
lished, recommending a geologist who wanted to see
volcanoes to choose Auvergne rather than Vesuvius
or Etna. 2 His views were thus well known to Hatty
and Ramond when they recommended D'Aubuisson
to betake himself to the same volcanic region.
When his fuller account of his rambles in Auvergne
appeared, its very first sentence betrayed a curious
ignorance or forgetfulness of the literature of the
subject. " Here we are," he says, " in a region about
which the naturalists of France have talked so much,
to which they have persistently referred us, but which
they have never yet described to us." It is difficult
to believe that Von Buch had never seen Desmarest's
papers and accompanying maps. Yet throughout the
whole account which he gives of his excursions he does
not once refer to them, but writes as if he were almost
1 The descriptions of Auvergne are contained in an Appendix to
vol. ii., consisting of Mlneralogische Brlefe aus Auvergne an Herrn
Geh. Ober-Bergrath Karsten, p. 227 (1809).
^Journal des Mines, vol. xiii. 1802-1803, p. 249. Boue, in an
obituary notice of Von Buch, says picturesquely that " in the year
1798 the learned geognost left Germany a Neptunist and came home
in 1800 a Vulcanist." His conversion, though as complete, was
not quite so rapid, for even after his visit to Italy and Central
France, though he gave up some parts of the Wernerian system, he
still clung tenaciously to others which he afterwards abandoned.
248 Von Buck's recantation
the first geologist who had ever made any detailed and
exact observations in the country. 1
Nothing could be more explicit than Von Buch's
testimony to the volcanic origin of the basalts of
Auvergne. The marvellous cone and crater of the
Puy de Pariou excited, as they well might, his aston-
ishment and admiration. " Here," he says, " we find
a veritable model of the form and degradation of a
volcano, such as cannot be found so clearly either at
Etna or Vesuvius. Here at a glance we see how the
lava has opened a way for itself at the foot of the
volcano, how with its rough surface it has rushed
down to the lower grounds, how the cone has been
built above it out of loose slags which the volcano
has ejected from its large central crater. We infer
all this also at Vesuvius, but we do not always see it
there as we do at the Puy de Pariou."
Perhaps the most interesting passages in Von Buch's
brightly-written letters are to be found at the end. The
obviously volcanic origin of the rocks in Auvergne,
and their position immediately above a mass of granite
through which the craters had been opened, had
evidently powerfully impressed his mind. With all
these recent vivid experiences, he reflects upon his
earlier wanderings among the basalt hills of Germany,
and, as if taking his readers into his inner confidence,
he declares that "it is impossible to believe in a
1 He refers indeed several times to Montlosier's Essai sur les Folcans
<?4uvergne, which he calls an excellent work. In one passage he
actually credits this author with some of the most important
generalisations made by Desmarest. (Geog. Beobacht., pp. 279, 280.)
2 Op. cit, p. 240.
Von Buck on Basalt 249
particular or local formation of basalt, or in its flow-
ing out as lava, when we know what the relations of
this rock are in Germany, and when we remember how
many different kinds of rocks are there associated
with basalt as essential accompaniments, how these
rocks form with basalt a connected whole which is
absolutely inconsistent with any notion of volcanic
action a peculiar coal formation, entirely distinct
from any other, only found with basalt and entirely
enclosed among basaltic rocks, often even a peculiar
formation of limestone." *
This was the one side of the picture. He could
not yet break entirely the Wernerian bonds that held
him to the beliefs he had imbibed at Freiberg. He
could not bring himself to admit that all that his
master had taught him as to the origin of basalt, all
that he had himself so carefully noted down from his
extended journeys in Germany, was radically wrong.
He, no doubt, felt that it was not merely a question
of the mode of origin of a single kind of stone.
The whole doctrine of the chemical precipitation of
the rocks of the earth's crust was at stake. If he
surrendered it at one point, where was he to stop ? We
cannot wonder, therefore, that he still refused to permit
himself to question the truth of the Wernerian faith
in so far as the old basalts of Saxony and Silesia were
concerned. He comforted himself with the belief that
they at least, with all their associated sedimentary
strata, must have been deposited by water.
But when he turns round again to the clear evidence
displayed in Central France, he asks, " Is it the fault of
1 Op. tit. p. 309.
250 Von Buck on Basalt
the geologist in Auvergne that the arguments which are
powerful in Germany have no effect on him here, even
though he does not dispute them ? May he not be
allowed in retort to ask whether the principles which so
obviously arise from the phenomena in Central France
are not also applicable to the German basalts ? At all
events, he may contend, we see very little connection
between these basalts and ours as regards relations of
structure. Would you have us give up our convictions
as to the principles which give grandeur, consistency,
and simplicity to the explanation of our Auvergne
mountains, and adopt views founded on relations
which are not to be seen here ? " *
Well might Von Buch conclude by saying that he
" stands perplexed and embarrassed." Whatever he
may think of the basalts of Auvergne, he will not
allow the Vulcanist to wrest his admissions to any
general conclusion with regard to the German basalts.
u Opinions are in opposition which only new observa-
tions can remove."
Von Buch's faith in the Wernerian interpretation of
volcanoes and basalt-hills had a rude shaking from his
excursions in Italy and Central France. His next
great journey taught him that Werner's scheme of
geological succession could not be maintained. Before
his volume descriptive of the Italian tour was published,
he had started for Norway, where he remained hard at
work for no less than two years. Among the vast mass
of important observations which he made, one that
must have greatly impressed him was that in which
he satisfied himself that the rocks in the Christiania
1 O/. '/. p. 310.
Emancipation from IVernerianism 251
district could not be arranged according to the Wer-
nerian plan which there completely broke down. Von
Buch found a mass of granite lying among fossiliferous
limestones which were manifestly metamorphosed, and
were pierced by veins of granite, porphyry, and syenite.
Such observations did not lead him, any more than
those in Central France, to a formal renunciation of
Wernerianism. But they enabled him to take a wide
and independent view of Nature, and gradually to
emancipate himself from the narrower views in which
he had been trained at Freiberg. 1
Von Buch's memorable investigation of the proofs of
the recent uprise of Scandinavia contributed still further
to expand his geological horizon. When he announced
that the whole of the continent of Sweden from Fre-
derikshald to Abo is now slowly rising above the sea,
he did as much as any Vulcanist of his day in support
of the theory of the earth promulgated by Hutton.
A further emancipation from the tenets of Freiberg
was displayed by a series of papers on the mountain-
system of Germany, wherein Von Buch gave the first
clear description of the geological structure of Central
Europe. He declared that the more elevated moun-
tains had never been covered by the sea, as Werner
had taught, but were produced by successive ruptures
and uplifts of the terrestrial crust. In 1824 he pro-
duced a geological map of the whole of Germany in
forty-two sheets, the first large map of its kind to illus-
trate a great area of the European continent, and a
signal monument of its author's unwearied research
iSee his " Reise nach Norwegen und Lappland," Gesammelte
Schriften, vol. ii. p. 109.
252 Labours of Von B^lch
and of his geological acumen. For more than sixty
years this distinguished man continued to enrich geo-
logical literature with memoirs contributed to scientific
societies and journals, and with independent works.
His earliest writings stamped him as an observer of
great sagacity and independence, and his reputation
rose higher every year, until he came to be the
acknowledged leader of geological science in Germany.
Pressing forward into every department of the science,
he illuminated it with the light of his penetrating
intellect. From the North Cape to the Canary Islands
there was hardly a region that he did not personally
explore, and not many that he did not describe.
With ceaseless industry and exhaustless versatility, he
ranged from the structure of the Alps to that of the
Cystideans, from the distribution of volcanoes to that
of Ammonites, from the details of minerals and rocks
to the deepest problems in the history of the globe. 1
His influence in his time was great. Though he
began as a Wernerian, he gradually and almost uncon-
sciously passed into the ranks of the Vulcanists. In
no respect did he show his independence and love of
truth more than in his long and enthusiastic researches
among volcanoes. No vulcanist could have worked
out more successfully than he did the structure and
history of the Canary Islands.
Among the leaders of geology in the first half of this
1 Von Buch's collected writings form four large closely-printed
octavo volumes. The Royal Society's Catalogue assigns I 5 3 separate
papers to him. For a biographical account of Von Buch see the
sketch by W. Haidinger in Jahrb. k. k. geol. Reichsanst. Band iv.
P- 2O 7> an( i tne notices prefixed to his collected works.
Personal characteristics 253
century there was no figure more familiar all over
Europe than that of Von Buch. Living as a bachelor,
with no ties of home to restrain him, he would start off
from Berlin, make an excursion to perhaps a distant
district or foreign country, for the determination of
some geological point that interested him, and return,
without his friends knowing anything of his move-
ments. He made most of his journeys on foot, and
must have been a picturesque object as he trudged
along, stick in hand. He wore knee-breeches and
shoes, and the huge pockets of his overcoat were
usually crammed with note-books, maps, and geological
implements. His luggage, even when he came as far as
England, consisted only of a small baize bag, which
held a clean shirt and silk stockings. Few would
have supposed that the odd personage thus accoutred
was one of the greatest men of science of his time, an
honoured and welcome guest in every learned society
of Europe. He was not only familiar with the writings
of the geologists of his day, but knew the men person-
ally, visited them in their own countries, and with many
of them kept up a friendly and lively correspondence.
He had an extensive knowledge of the languages of
Europe, and had read widely not only in his own sub-
jects, but in allied sciences, in history, and in literature,
ancient and modern. Kindly, frank, outspoken, and
fearless, he was beloved and honoured by those who
deserved his friendship, and dreaded by those who did
not. With tender self-sacrifice he would take his blind
brother every year to Carlsbad, and with endless bene-
factions did he brighten the lives of many who survived
to mourn his loss. He died on 4th March 1853, in
254 G. de Dolomieu
the seventy-ninth year of his age. A fitting monument
to his memory was raised by subscriptions from all over
Europe. In the picturesque region of Upper Austria,
not far from Steyer, a granite boulder 1 6 feet high that
had been borne by a former glacier from the Alps was
chosen as his cenotaph. The stone, chiselled into a flat
surface, bears inscribed upon it, with the reverence of
admirers in Germany, Belgium, France, England, and
Italy, the immortal name of Leopold von Buch. 1
While D'Aubuisson and Von Buch were, even in
Werner's lifetime, emancipating themselves from the
tenets of the Freiberg School, various other observers,
without definitely becoming controversialists, were pro-
viding a large body of material which eventually proved
of great service in the establishment of a sound geology.
Chief among them were those who devoted themselves
with such ardour to the study of the Italian volcanoes.
One of the most active and interesting of their number
was Gratet de Dolomieu (1750-1801), who, born in
Dauphine, died at the early age of fifty-one, after a
strangely eventful life. At the age of 25 he published
some works on science, for which he was elected a
correspondent of the Academy of Sciences of Paris. He
thereafter took to geological and mineralogical explora-
tion, making his journeys on foot, with a bag on his
back, and a hammer in his hand, and studying successively
the minerals and rocks of Portugal, Spain, Sicily, the
1 An account of the movement for the preparation of this monu-
ment will be found in Das Buch-Denkmal, a pamphlet by Ritter von
Hauer and Dr. Homes, published in Vienna in 1858. It gives
a portrait of Von Buch, and a view of the monument, with a
map showing the position of the site.
Faujas de St. Fond 255
Lipari Islands, the Pyrenees, the Alps, the Apennines,
Central France, and the Vosges. He made extensive
collections of specimens, and published many memoirs
descriptive of the regions he visited. His attention was
especially drawn to the active and extinct volcanoes of
the Mediterranean basin. As far back as 1776 he
made the announcement that he had found in Portugal
evidence of volcanoes older than certain mountains of
limestone a statement which he supplemented in 1784
with further evidence from Sicily, proving the inter-
calation of ancient lavas among stratified deposits. 1
To this important discovery further reference will be
given on a later page.
Among his other writings allusion may here be
made to his little volume on the Lipari Isles, to the
paper in which, following Desmarest, he described
the old volcanoes of Central France, and to his
u Memoire sur les lies Ponces." 2 Though his theo-
retical views were not always sound, he was a careful
and indefatigable observer, and provided copious
material towards the establishment of the principles
of geology. To him more than perhaps to any of
his contemporaries is science indebted for recognising
and enforcing the connection of volcanoes with the
internal heat of the globe.
Faujas de St. Fond (1742-1819) did excellent
service by his splendid folio on the old volcanoes
of the Vivarais and the Velay a work lavishly illus-
trated with engravings, which, by showing so clearly
the association of columnar lavas with unmistakable
1 Journ. de Phys. xxiv., Septembre 1784, p. 191.
2 Journ. des Mlnes y vol. vii. (1798), pp. 393-405.
256 Spallanzani, Breislak
volcanic cones, ought to have done much to arrest
the progress of the Freiberg doctrine of the aqueous
origin of basalt. 1 The same good observer undertook
a journey into the Western Isles of Scotland towards
the end of the eighteenth century, 2 when that region
was much less easily visited than it now is, and con-
vinced himself of the volcanic origin of the basalts
there, thus adding another important contribution to
the literature of volcanic geology.
Spallanzani (1729-1799), the illustrious professor of
Pavia, Reggio, and Modena, born in 1729, devoted
his earlier life to animal and vegetable physiology,
and was fifty years of age before he began to turn
his attention to geological questions. But from that
period onward he made many journeys in the basin of
the Mediterranean from Constantinople to Marseilles.
Of especial interest were his minute and picturesque
descriptions of the eruptions of Stromboli, which at
not a little personal risk he watched from a crevice
in the lava. His Travels in the Two Sicilies and in
some Parts of the Apennines contained a mass of careful
observations among the recent and extinct volcanoes of
Italy. 8
Another Italian vulcanist well worthy of remem-
brance was Scipio Breislak (1748-1826) who, born in
Rome and destined for the church, showed so strong a
bent for scientific pursuits that he was eventually made
professor of natural philosophy and mathematics at
1 Recherche* sur les Volcans eteints du Vivarais et du Velay, folio, 1778.
2 Voyage en Angleterre, en Ecosse, et aux lies Hebrides, ^ vols. 8vo,
1797.
3 Viaggji alle due Sic Hie, 1792-93.
Montlosier 257
Ragusa, whence he passed to the Collegio Nazareno
at Rome. His fondness for geological studies led
to his appointment by Napoleon " Inspecteur des
poudres et salpetres" in the kingdom of Italy,
which gave him the opportunity of making himself
personally acquainted with the geology of a large
part of his native country. Powerful as an advocate
for the Vulcanist doctrines in opposition to the prevail-
ing Neptunism of his time, he wrote some excellent
monographs on the geology of different parts of
Italy, particular y of the Campania ; also an Intro-
duction to Geology, of which a French version was
published in 1812, and a more important treatise
which, translated into French from his Italian manu-
script, was published at Milan in three volumes in
1818. The attitude which Breislak took towards the
Freiberg School may be inferred from his remark
" I respect the standard raised by Werner, but the
flag of the marvellous and mysterious will never be
that which I shall choose to follow." *
Reference has been made in an earlier chapter
(p. 159) to F. D. de Reynaud, Comte de Montlosier
(1755-1838) who is chiefly known as a distinguished
French publicist. He went into exile at the time of
the French Revolution, but ultimately returned to
France, and in the end became a member of the
Chamber of Peers where, even when he had passed
his eightieth year, he continued to be one of the most
assiduous orators. He was the author of many political
writings, but deserves mention here for the small
treatise which he published in 1789 and which, as we
1 Introduzione alia Geologia, 2 vols. 8vo, 1811.
R
258 Montlosier on Vulcanism
have seen, proved useful to Von Buch in Auvergne.
Montlosier, being an Auvergnat proprietor, had from
his boyhood been familiar with the physical features of
that interesting region. His Essai gives a lively ac-
count of the volcanic district from his own personal
rambles, but it contains nothing of importance that is
not to be found in the earlier writings of Desmarest,
whose views he adopts, but without citing him as his
authority. The last chapter of the Essai is devoted to
a discussion of the nature of volcanic force, which the
author regarded as something distinct from the " fire,"
and perhaps of the nature of electricity, "the energy
whereof is increased under ground by chance encounter
with certain antagonistic materials." He was at all
events convinced that " neither coal, nor bitumen, nor
any of the other substances known to us can possibly
be the principle of volcanic force, which acts indiffer-
ently upon everything it meets with."
So long as the crude conception prevailed that
volcanic action was due to the combustion of beds
of coal or other inflammable materials, it was an
obvious consequence that the production of volcanoes
should be regarded as a comparatively modern feature
in the history of our planet. Not until thick forests
had flourished on the earth's surface, and had been
buried deep under accumulations of sediment, could
any subterranean conflagrations be expected to arise.
But there was yet another influence which could not
but retard the recognition of evidence of ancient
volcanic eruptions preserved among the strata of the
earth's crust. Hutton and his school, whose contri-
butions to geological progress will be described in
Plutonist mews of Igneous Rocks 259
the next chapter, while they vigorously contended
for the igneous origin of the " whinstone " (basalt)
rocks, in opposition to the teachings of the Neptunists,
looked upon these rocks as " not of volcanic, nor of
aqueous, but certainly of igneous origin," having been
" formed, in the bowels of the earth, of melted matter
poured into the rents and openings of the strata." 1
So intent were the Plutonists on collecting all the
evidence they could find in favour of the deep-seated
and intrusive origin of these masses, that they naturally
neglected or explained away, in accordance with their
own theory, the cases where there was no evidence
of intrusion. The Neptunists, on the other hand,
seized upon these very cases in support of their
contention that sheets of basalt regularly inter-
stratified with aqueous deposits must themselves
have been precipitated from solution in water. The
disputants on neither side perceived that a third
and entirely distinct explanation of the facts could
be given. If the strata of sedimentary materials
were accumulated under water, as was universally
admitted, might not the sheets of basalt and other
presumably volcanic materials have been erupted
upon the floor of that water, whether sea or lake,
so as to alternate with the normal deposits of
sediment ?
Already two acute observers had led the way
towards this, the true solution of the apparent con-
tradiction, though neither school of combatants would
accept their explanation. Desmarest, as we have seen,
(p. 1 66) had declared as far back as 1775, that traces
1 Playfair's Illustrations of the Huttoman Theory, 234, 239.
26 o Dolomieu on Submarine eruptions
of ancient subaqueous volcanic eruptions have been
preserved among the sedimentary strata that overlie the
granite of Auvergne. A year or two later, Dolomieu
pointed out the evidence for the contemporaneous
interstratification of volcanic sheets among ordinary
marine deposits. He first directed attention to the
subject in 1776, and brought forward still more clearly
in 1784 proofs of ancient eruptions preserved in a
series of marine limestones. 1 He showed that in
the Val di Noto in Sicily such limestones, abound-
ing in large corals and shells, attain a considerable
thickness and lie in horizontal beds of white rock,
alternating with numerous intercalations of dark vol-
canic material. He found in one section eleven such
prominent alternations, though if he had included the
layers not more than an inch thick, this number would
have been doubled. The volcanic material varied
from band to band, two-thirds consisting of frag-
mental detritus, and the remainder of sheets of
basalt, sometimes regularly columnar. The most
abundant constituent was a black sand or tuff, which
had been laid down in thin layers, with the coarsest
particles at the bottom. Some of the bands consisted
of a conglomerate made up of blocks of different
lavas cemented together in a calcareous or argillaceous
matrix. In all the limestones Dolomieu found volcanic
fragments to be generally present. He observed that
the basalt-sheets sometimes lie directly on a floor of
limestone, sometimes on a layer of aggregated cinders,
and that in the former case the two rocks are inter-
1 " Sur les Volcans teints du Val di Noto en Sicile," Journ. de
Physique, xxv., Septr. 1784, p. 191.
Play fairs criticism of Dolomieu 261
mingled along the junction-plane. He rightly reasoned
that these facts demonstrate the contemporaneous dis-
charge of volcanic products over the sea-bottom, at the
time when the limestones were in process of accumula-
tion. He found a difficulty, however, in explaining
how the basalts could have flowed so far as perhaps ten
leagues, without becoming solid, and he thought that
the vents from which the eruptions proceeded in such
long succession must have rapidly risen above sea-
level, otherwise their fires would have been speedily
extinguished by the rush of the water down into their
craters. The submarine volcanic series of younger
Tertiary age in Sicily is now well known from the
labours of subsequent observers, but it is not always
pointed out that the credit of the original discovery
of it belongs to Dolomieu.
Play fair was fully acquainted with the arguments
of the French geologist, and refers to them with
characteristic candour. He brings forward what he
considers "insuperable objections" to them objec-
tions which in the light of present knowledge are
easily removable but he frankly admits the value
of Dolomieu's explanation of the facts by granting
that " it makes a considerable approach to a true
theory, and that the submarine volcanoes of Dolo-
mieu have an affinity to the unerupted lavas of Dr.
Hutton." 1
The long continuance of the Huttonian prejudice
in favour of these " unerupted lavas " can hardly
be better illustrated than by reference to the Descrip-
tion of the Western Islands of Scotland, by John
1 Illustrations, 243.
262 y. Macculloch, K. C. von Leonhard
Macculloch (1773-1835), published in 1819. This
now classic work undoubtedly gave a great impetus
to geological progress, especially in the department of
the science which deals with the igneous rocks. The
number and striking character of the illustrations
which it afforded of the truly eruptive nature of
these rocks did much to strengthen the Plutonist
cause throughout the world. Yet though the region
described included the great basalt-plateaux of the
Inner Hebrides, with what we now recognise to be
their abundant evidence of the superficial outpouring
of streams of basic lava and showers of volcanic
ashes, in continuous sequence, as clearly exposed
along hundreds of miles of sea-precipices, no reader
of Macculloch's volumes would be likely to gather
from them that any such record of prolonged volcanic
activity is to be found in the West of Scotland. Even
so late as the year 1832, K. C. von Leonhard, in
his ample monograph on Die Basalt-Gebilde, fully
describes the volcanic features of these rocks as dis-
played in Auvergne, the Eifel and other districts, but
when he comes to deal with the sheets of basalt
intercalated among the strata of the Earth's crust, he
is chiefly careful to mark their connection with dykes,
and the proofs they furnish that they have been injected
into and have altered the contiguous strata. It would
almost appear that if in the earlier years of last century
a Vulcanist had maintained the contemporaneity of a
basalt-sheet with the sedimentary deposits among which
it lay, he would have run some risk of being regarded
as having gone over to the Neptunist camp.
Notwithstanding the lessons so clearly taught by
Slow progress of Volcanic Geology 263
Desmarest from the structure of Auvergne, and by
Dolomieu from that of the Val di Noto, many years
had to pass away before it began to be generally
realised that all the sheets of igneous material inter-
calated among the sedimentary formations of the
terrestrial crust are not plutonic intrusions, but that
not a few of them are unquestionably lavas and
ashes, thrown out by once active volcanoes, either
under the sea or on land. Only by slow steps of
investigation was the truth at last ascertained and
admitted that volcanic action has been abundant all
over the globe, from the earliest geological times, and
that a record of its successive phases has been pre-
served among the rocks.
When at last the controversy as to the origin of
basalt, and the eruptive character of the so-called
"Trap-rocks" had been settled, and men were able,
apart from the disputes of the rival schools, to look at
these rocks impartially, with the view of learning what
record they have to contribute to the history of the
earth, it was fitting that progress in this subject should
begin to be made in Britain a portion of the earth's
surface which, for its size, contains a fuller chronicle
of past volcanic activity than any other land hitherto
examined. A brief outline of the early stages of this
research within the British Isles will show how slowly
yet how securely the foundation stones in this depart-
ment of geology were laid.
Among the followers of the Wernerian faith who
early emancipated themselves from Werner's doctrines
regarding volcanic rocks, an honourable, place must
be assigned to Ami Bou (1794-1881). Born in
264 Ami Boue
Hamburg, but of Swiss parentage and old French,
descent, he was sent for his medical education to the
University of Edinburgh, where he graduated as
M.D. in the year 1816. But his strong bent
towards natural history pursuits led him to take up
geology, in which he was trained after the Wer-
nerian system by Jameson. He rambled far and
wide over Scotland, and formed his own conclu-
sions as to the origin and age of many of the igneous
rocks so abundantly developed in that country. Leav-
ing Edinburgh, he settled for a time in Paris, and while
there, wrote an excellent treatise in French, with the
title of Essai Geologique sur I'Ecosse, which though it
bears no date, appears to have been published in the
year 1820. In many respects this remarkable work
was far in advance of its time, particularly in regard
to the views expressed in it regarding the trappean
rocks. Boue's acute eyes recognised the volcanic
nature of the great series of " roches feldspathiques
et trappeennes " of central Scotland, which he claimed
to mark eruptions in the time of the Old Red Sand-
stone. He boldly introduced for the first time, into-
the geological table for that country, a division entitled
" Terrain Volcanique," wherein he included not only
the younger basalts of the Inner Hebrides which
had been described by Faujas St. Fond, Macculloch
and others, but also the basalts, andesites, trachytes >
tuffs and other rocks intercalated in the Carboniferous
system.
On the other hand, Charles Daubeny (1795-1867)
another pupil of Jameson, who afterwards wrote an.
excellent treatise on volcanoes, could so late as 1821
Charles Daubeny, Henry T. De la Beche 265
still speak of granite passing into sandstone, of " fire
and water, although such opposite agents, having in
some instances, produced effects nearly, if not alto-
gether identical," and of the probability that what is
now known to be a typical and admirable series of
alternations of basalt-lavas with tuffs and sedimentary
fossiliferous strata, was entirely the product of aqueous
deposition. 1
But in the third and fourth decades of the nine-
teenth century a number of independent observers had
their attention aroused by the intercalation of rocks
which they could only regard as volcanic, among the
older stratified formations of Britain. In his singularly
suggestive volume entitled Researches in Theoretical
Geology r , published in 1831, Henry Thomas De la Beche
(1796-1855) expressed, though cautiously, his opinion
that some at least of the " trappean " rocks associated
with the lower parts of the " grauwacke series " in
different countries of Europe, appear to have been
contemporaneous with the strata among which they lie,
" precisely as a bed of lava may flow over a sandy
1 Letters to Professor Jameson, Edln. Phil. Journ., 1820-21. In
Conybeare's Introduction to Conybeare and Phillips* Outlines of the
Geology of England and Wales, published in 1822, regretful reference
is made to the " excessive addiction to theoretical speculations " on
the part of the zealous rival partizans of the Huttonian and
Wernerian systems at Edinburgh. The author refrains from pro-
nouncing any judgment on the controversy as to the origin of
the Trap rocks, being desirous " to keep these conjectural specula-
tions entirely distinct from that positive knowledge, acquired from
observation, which is as yet the only certain portion of geological
science." One can see that, in spite of this laudable caution,
Conybeare's sympathies were rather in favour of the igneous
views.
266 De la Beche on Ancient Volcanoes
bottom and afterwards be covered up by a deposit of
sand or mud." He had himself observed considerable
accumulations of " comminuted trappean matter " among
the greenstones and porphyries of the older grauwacke
of Devon and Cornwall, and was inclined to believe
them to represent volcanic ashes ejected at the time
that the associated sediments were in course of de-
position. He was thus led to suppose " that there
had been ejections of igneous matter into the atmo-
sphere or beneath shallow water, and consequently that
we might expect to discover similar facts among the
other fossiliferous rocks, under favourable circumstances
and in different parts of the world." 1
While these observations were in progress in the
south of England, another series on a larger scale was
advancing in the Lake District of the north. In that
mountainous tract Adam Sedgwick (1785-1873) had
spent some years, tracing the intricate structure of the
ground, and had found a great group of green slates
and porphyries, comprising fine compact slates with
coarse granular concretionary masses and breccias or
pseudo-breccias ; likewise amorphous, semi-columnar,
prismatic porphyries, which did not take the form of
dykes nor altered the limestone that rests upon them.
He therefore " inferred that the whole group is of
1 Op. /. pp. 384, 385. The "ashes" here referred to are of
Middle Devonian age. He also recognised the probable con-
temporaneous eruption of the trappean rocks associated with the
much younger red conglomerate of South Devon which may be
Permian. Geological Manual, 1831, p. 389. The progress of the
Geological Survey in later years enabled De la Beche to add
fresh details regarding the Lower Silurian volcanic rocks of Southern
Wales. Mem. Geol. Survey, vol. i. (1846) pp. 29-36.
Sedgwick on Palceozoic Volcanoes 267
one formation which has originated in the simul-
taneous action of aqueous and igneous causes long
continued." 1
Sedgwick next turned his attention to the compli-
cated geological structure of the mountainous region of
North Wales, and after great labour succeeded in
unravelling it. Among the important additions to
geological science made by him at this time was
the recognition of the intercalation of vast masses of
igneous rocks among the ancient sedimentary series
(Cambrian and Lower Silurian) of that region. He
distinguished trappean conglomerates, contemporaneous
sheets of " felstone-porphyry " and " felstone," and
found the two classes of aqueous and igneous rocks
so interlaced that they could not be separated and were
regarded by him as of contemporaneous origin. He
likewise noted the presence of later intrusions of
" greenstone " and other trappean masses. Thus the
existence of a vast complex of ancient Palaeozoic lavas,
tuffs, and breccias was introduced into geological
literature. 2
While the Woodwardian Professor was at work
1 Proc. Geol. Soc. vol. i. p. 248 (5th January, 1831) and p. 400
(2nd May, 1832).
2 Proc. Geol. Soc. ii. (1838) pp. 678-9; iii. (1841) p. 548 ; iv.
(1843) p. 215. Quart. Journ. Geol. Soc. i. (1843) pp. 8-17; iii.
(1846) p. 134. In the last cited paper Professor Sedgwick speaks
-of at least ninety hundredths of the trappean rocks of North Wales
being of contemporaneous origin with their associated strata ; but
he regards them all as essentially "subaqueous or plutonic." He
shows how they have been involved in all the latter plication of
the region, and how they may be used as recognisable and well-
defined stratigraphical platforms.
268 Murchisons Volcanic Researches
in North Wales his friend Roderick Impey Murchison
(1792-1871) was engaged on the borders of the
Principality in attacking the sedimentary (grauwacke)
strata that emerge from under the base of the Old Red
Sandstone, as will be more particularly noticed in
Chapter XIII. He had not advanced far in this
investigation before he in turn was confronted with
many examples of what were evidently igneous rocks,,
intercalated among the stratified formations to which
he was more specially directing his attention. In one
of his papers, read before the Geological Society in
1824, he shows at what an early period in his inquiries
he had detected proofs of true volcanic masses associ-
ated with these formations. He there remarks " that as
some of the porphyritic and felspathic rocks alternate
conformably with strata of marine origin, containing
organic remains of a very early period, and as some of
the layers in which such remains are imbedded have
a base of true volcanic matter, the date of the origin of
this class of rock is thereby fixed. These conformable
alternations of trap and marine sediment establish a
direct analogy between their mode of production and
those replications of volcanic ejections and marine
deposit which are now going on beneath the present
seas ; whilst they further explain the manner in which,
in times of the highest geological antiquity, the porphyry-
slates were arranged in parallel laminas with the sedi-
mentary accumulations of that age. The existence of
certain strata containing organic remains, yet possessing
a matrix composed in great measure of the same
materials as the adjacent ridges of trap-rock, has
strengthened the inference that some of the ebullitions
Hay Cunningham, Charles Maclaren 269
of these submarine volcanoes were contemporaneous
with the period in which these animals lived and died,
the finer volcanic ejections having, it is presumed, led
to the formation of the volcanic sandstone." 1
In Scotland, after the war between the Plutonists and
the Neptunists had ceased, a period of calm, almost of
stagnation ensued, so far at least as regarded the inves-
tigation of igneous rocks. While it was now generally
conceded that these rocks had really resulted from the
action of subterranean causes, the old Huttonian idea
still prevailed that they had all been injected among
the strata at some depth beneath the surface. Even
so late as 1834 when Hay Cunningham, a pupil of
Jameson, began to prepare the materials for his essay
on "The Geology of the Lothians,'"^ he failed to
distinguish between the intrusive and contempor-
aneously intercalated sheets of igneous rock, although
each series is admirably developed in the region which
he had to investigate and describe. In the year 1839
there was published by far the most important treatise
that had yet been devoted to the description of any por-
tion of the ancient volcanic rocks of Britain the Sketch
of the Geology of Fife and the Lothians by Charles
Maclaren. In this classic work the structure of two
groups of hills Arthur's Seat and the Pentlands was
worked out in ample detail, and the volcanic history of
each of them was admirably traced. In the one case,
l Proc. Geol. Soc. ii. (1834) p. 92. Fuller discussion of the subject,
with ample local details, was given in his Silurian System, which was
published at the end of 1838. See especially pp. 225, 258, 268,
287, 317, 324 and 401.
2 Mem. Werner 'Ian Soc. vol. vii.
270 The Geological Survey of Great Britain
the successive outflows of a series of " clay stone ""
" clinkstone " and " porphyry " lavas, from subaqueous-
craters or fissures, belonging to the time of the Old
Red Sandstone, was demonstrated by conclusive proofs,
In the other, the combination of subterranean injec-
tion and superficial outflow from a crater of Lower
Carboniferous age was clearly shown, together with
evidence of alternations of basalt-lavas with volcanic
tuffs, succeeded by prolonged denudation and a
subsequent renewal of volcanic activity on the same
site. The author, by appeals to the known behaviour
of modern volcanoes, illustrated each main feature in
the history of these ancient centres of eruption. His
convincing and suggestive essay ought to have
immediately stimulated the investigation of the subject
in other parts of the same region, where innumerable
examples of the phenomena, on even a more striking
scale, remained still unknown or misunderstood. But
Maclaren did not himself continue his volcanic
researches, nor for nearly twenty years did any one
arise to take up again the work which he had sa
well begun.
The Geological Survey in Wales developed with
great detail the history of the igneous rocks which
had been briefly noticed by Sedgwick and Mur-
chison. Subsequently the extension of the Survey
to Scotland in 1854 brought to light the remarkable
fulness of the volcanic record in that kingdom.
Gradually this record has been deciphered for the
whole of the British Isles, which are now found to
include a singularly varied and prolonged succession
of volcanic rocks, extending through Palaeozoic time
Progress of Volcanic Geology abroad 271
and another wide-spread and complicated series dating
from the older part of the Tertiary period. 1
It is unnecessary to trace the progress of investi-
gation in other countries regarding the volcanic action
of former geological periods. In Germany, the lavas
and tuffs of Devonian and Permian age have long
been made familiar by many able writers. In France,
besides the complicated history of the Tertiary volcanic
history which, first sketched in broad outline by
Desmarest, has been followed into the minutest details
by Fouque, Michel Levy, Boule and other observers,
a great series of Palaeozoic eruptions has been
brought to light by Barrois. In the United States
also, a long and complicated volcanic record, dating
from older Tertiary time, has been made known by
the geologists of the various surveys which have been
extended over the Western States and Territories.
And thus the present active volcanoes of the globe
have been shown to be the latest in a series which
can be traced backwards into the remotest geological
periods.
We have seen in the course of these chapters that
volcanoes and earthquakes were assumed, even as far
back as the time of the ancient Greeks and Romans,
to be connected phenomena arising from one common
cause, but that no attempt was made during all the
subsequent centuries either by close observation or
well-devised experiment to discover what this active -
cause might be. The prevalent opinion was that
which looked upon subterranean wind as the main
1 I have given a full account of this volcanic history in my
Ancient Volcanoes of Great Britain, 2 vols., 1897.
J
272 Early investigations of Earthquakes
agent of commotion, aided by the collapse of the
roofs or sides of underground caverns. When the
disturbance of the air in these recesses reached a
I maximum of intensity its friction or that of falling
/ masses of loosened rock set fire to combustible mate-
\ rials, and eventually the wind and hot vapours forced
\their way with violence to the surface in volcanic
explosions. That earthquakes are common in volcanic
districts had been recognised from the earliest times,
but they had been experienced also in regions where
there were no active volcanoes. In the latter case
they were regarded as volcanic convulsions which had
not succeeded in opening a vent above ground. But
down to the middle of the eighteenth century no real
progress had been made in the solution of the problem
of their origin.
The year 1750 was remarkable for the number of
earthquakes which at that time affected the west of
Europe, and which caused some alarm in the south
of England. The Royal Society collected and pub-
lished the narratives of many observers, and likewise
some lucubrations on the " philosophy of earthquakes."
The same century was distinguished for its great activity
and rapid advance in the investigation of electricity.
This new and still mysterious force, so stupendous,
sudden and swift in its operation, seemed to some
minds to offer a probable explanation of the pheno-
mena of earthquakes. The earliest writer who tried
to picture to himself the manner in which electricity
acts in the process seems to have been Dr. Stukeley,
who contributed several communications on the subject
to the Philosophical Transactions of the Royal Society.
Stukeley and Michell on Earthquakes 273
He " did not enter into the common notion of
struggles between subterraneous winds, or fires,
vapours or waters, that heaved up the ground like
animal convulsions ; but always thought it was an
electrical shock, exactly of the same nature as those,
now become very familiar in electrical experiments."
In one passage he remarks that, owing to peculiar
meteorological conditions, a wide extent of country
is sometimes brought into a highly electrified state
and that if then a " non-electric cloud " should dis-
charge its contents, in a heavy shower of rain, " an
earthquake must necessarily ensue." In another part
of the same essay he refers to "a black sulphureous
cloud " which comes " at a time when sulphureous
vapours are rising from the earth in greater quantity
than usual ; in which combined circumstances, the
ascending sulphureous vapours in the earth may pro-
bably take fire and thereby cause an earth-lightning,
which is at first kindled at the surface, and not at
great depths, as has been thought ; and the explosion
of this lightning is the immediate cause of an earth-
quake." *
Of a very different stamp from these crude specu-
lations was an essay by the Rev. John Michell
(1724-1793) read before the Royal Society in the
spring of the year 1760. During the decade that
had elapsed since the "earthquake year" of 1750,
western Europe had not ceased to be shaken, and
there had happened the great Lisbon earthquake of
ist November 1755 the most extensive and disas-
trous catastrophe which had ever been recorded.
l Phil. Trans, vol. xlvi. (1750), pp. 643, 676.
274 Michell on Earthquakes
The keenest interest was consequently aroused in the
subject of earthquakes, and numerous reports from
eye-witnesses of the effects of that great disturbance
were printed in the 49th volume of the Philosophical
Transactions. Among the various papers Michell's
" Essay on the Causes and Phenomena of Earth-
quakes " stands out conspicuously as by far the most
important contribution to this branch of science that
had yet appeared in any language or country. Starting
on the assumption that earthquakes are due to the
sudden access of large quantities of water to subter-
ranean fires, whereby vapour is produced in sufficient
quantity and elastic force to give rise to the shock,
the author proceeds to adduce facts and arguments
in support of this hypothesis. In the course of the
discussion he points to the frequency of earthquakes
in the neighbourhood of active volcanoes, and to their
usual occurrence as accompaniments of volcanic erup-
tions. He states that the motion of the ground in
earthquakes is partly tremulous and partly propagated
by waves which, succeeding each other at intervals,
generally travel much further than the tremors. He
sees no difficulty in believing that subterranean fires
may continue to burn for long periods without the
access of air, and he adopts the idea that the spon-
taneous combustion of subterranean pyritous strata
among inflammable materials may be the cause of the
fires of volcanoes. If the vapours raised from these
fires, and finding an outlet at volcanic vents, are power-
ful enough to convulse the surrounding region to a
distance of ten or twenty miles, what may we not
expect from them when they are confined under
Michell on Earthquakes 275
ground and prevented from escaping ? When the
roof above one of the volcanic fires falls into the
molten mass below it, all the water contained in the
fissures and cavities would be precipitated into the fire
and be almost instantly raised into vapour, which, by
its first effort, would form a cavity between the melted
matter and the superincumbent rock. This rock
would thus be first compressed, and then, on recovery,
dilated, producing a vibratory motion at the surface
of the ground, and partially occasioning the noise that
accompanies an earthquake, though this may also be
due to the grating of the parts of the earth together
during the wave-like motion through them. The
waves propagated through the earth are largest above
their source of origin, and gradually diminish until
they may only be detected by the motion of sheets
of water and objects suspended from a height, as
hanging branches and lamps in churches.
Michell further remarks that while earthquakes are
frequent in mountainous districts, they are usually less
extensive there than those which originate under the
sea, and he thinks that far more extensive fires may
exist below the ocean than on land, where the mass
of material lying above them is less. In seeking to
find the focus of origin of an earthquake, this acute
writer points out that if lines be drawn in the direction
of the observed track of the earth-waves through all
the places affected, " the place of their common inter-
section must be nearly the place sought." He shows
that the great Lisbon earthquake had its origin under
the Atlantic, somewhere between the latitudes of Lisbon
and Oporto. While admitting that a sufficient number
276 Michell's Earthquake theory
of accurate data had not then been collected to
permit any satisfactory computation of the depth of
origin of earthquakes, which might considerably vary,
he yet thought that " some kind of guess might be
formed concerning it," and in illustration of such a
" random guess " he supposed that the depth at which
the Lisbon earthquake took its origin " could not be
much less than a mile, or a mile and a half, and pro-
bably did not exceed three miles."
From this brief summary of his opinions it will be
seen that Michell still laboured under the popular and
time-honoured delusion that volcanoes take their rise
from the combustion of inflammable strata below
ground, and that he attributed earthquakes exclusively
to the influence of these subterranean fires. Realising
that the sudden development of large bodies of vapour
within the terrestrial crust might start the disturbances
of earthquakes, he made a great onward step in show-
ing that successive waves would be generated in that
crust, and would travel outwards, in constantly diminish-
ing amplitude until they finally died away. It was
the first time that this conception of earthquake
motion had been laid before the world. Michell,
however, appears to have assumed the propagation of
the vapour to be the cause of the wave-like motion
of the ground. He speaks of the vapour "raising
the earth in a wave as it passes along between the
strata, which it may easily separate in an horizontal
direction." He refers to " the wave at the surface of
the earth occasioned by the passing of the vapour
under it," and states that "the shortest way that the
vapour could pass from near Lisbon to Loch Ness
A. Perry, R> Mallet 277
was under the ocean." But with all his limitations
we may yet rank him as the great pioneer of the
modern science of Seismology. 1
It was not until about the middle of last century
that scientific methods and instrumental research began
to be seriously applied to the study of earthquake
phenomena, and the modern science of Seismology
came into being. Alexis Perry of Dijon had rendered
important service by laboriously collecting statistics
of earthquakes from all countries and of all ages
back to the early centuries of our era. But it is more
especially to the labours of Robert Mallet (1810-
1881) that we owe the initial impetus which has led
to such valuable results in recent years. In 1846
he published a paper " On the Dynamics of Earth-
quakes/' 2 which, as he himself says of it, was " the
first attempt to bring the phenomena of the earthquake
within the range of exact science, by reducing to system
the enormous mass of disconnected and often dis-
cordant and ill-observed facts which the multiplied
1 Michell was specially distinguished as an astronomer. After
serving various offices at the University of Cambridge, where he had
graduated as fourth wrangler, he became rector first of St. Botolph's,
Cambridge, and for the last twenty- six years of his life, of Thornhill
in Yorkshire. He was a Fellow of the Royal Society, and author
of a number of remarkable papers on astronomical subjects. His
essay on earthquakes may have led to his being appointed in 1762
to the Woodwardian Professorship of Geology at Cambridge, but
it appears to be his only contribution to geological science. Not
only does it treat of the subject of its title, but it gives an excellent
account of the tectonic arrangement of the stratified formations, to
which further reference will be made in a later chapter.
2 Trans. Roy. Irish Acad. vol. xxi. (1846), p. 51.
278 Mallet's Earthquake Researches
narratives of earthquakes present, and educing from
these, by an appeal to the established laws of the higher
mechanics, a theory of earthquake motion." In this
his earliest contribution to the subject he announced
his famous definition of that motion as " the transit
of a wave of elastic compression in any direction,
from vertically upwards, to horizontally, in any
azimuth, through the surface and crust of the earth,
from any centre of impulse or from more than one,
and which may be attended with tidal and sound waves
dependent upon the former, and upon circumstances of
position as to sea and land." This epoch-making essay
was followed by his paper on the " Observation of
Earthquake Phenomena" contributed to the Admi-
ralty Manual of Scientific Enquiry in 1849, an ^
thereafter by a voluminous series of Reports pub-
lished by the British Association for the Advancement
of Science from 1850 to 1858. These Reports
included a Catalogue of recorded earthquakes from
1606 B.C. to A.D. 1850, and a full discussion of the
facts and theory of earthquake phenomena.
Mallet's enthusiasm in the study of these phenomena
received a vivid stimulus from the occurrence of the
Neapolitan earthquake of December 1857 the third
in point of extent and severity hitherto experienced
in Europe. Under the auspices of the Royal Society,
he was enabled to visit the scene of devastation in
southern Italy, shortly after the calamity, and to make
careful observations of the effects upon buildings
and upon the surface of the ground. The results of
his investigation formed the subject of his work in
two volumes The First Principles of Observational Sets-
Recent Earthquake Investigation 279
mology (Great Neapolitan Earthquake of 1857). Mallet
further contributed to our knowledge of the trans-
mission of waves of shock through the earth's crust
by exploding gunpowder and measuring the rate at
which the shock travels through different kinds of
materials, such as loose sand, on the one hand, and
solid granite, on the other.
The subsequent progress of seismology belongs
to a later time than falls within the limits marked
out for treatment here. The science has made a
great advance since Mallet's time, more particularly
as a consequence of the greater perfection of instru-
mental observation, and of the labours of Professor
John Milne and the native observers in Japan a
region where earthquakes are frequent and sometimes
of great violence. Such is the general interest in the
subject that observing stations, furnished with good
self-registering seismographs, are now to be found in
many parts of both hemispheres, and such is the
sensitiveness of these instruments that every severe
earthquake is detected and registered even at the
antipodes of the region from which it originates.
CHAPTER IX
RISE of the modern conception of the theory of the Earth. Hutton,
Playfair.
WHILE the din of geological warfare resounded across
Europe, and the followers of Werner, flaunting the
Neptunist flag in every corner of the continent, had
succeeded in making the system promulgated from
Freiberg almost supplant every other, a series of quiet
and desultory researches was in progress, which led
to the establishment of some of the fundamental
principles of modern geology. We have now to
turn our eyes to the northern part of the British
Isles, and to trace the career of a man who, with
singular sagacity, recognising early in life the essential
processes of geological change, devoted himself with
unwearied application to the task of watching their
effects, and collecting proofs of their operation, and
who combined the results of his observation and
reflection in a work which will ever remain one of
the great classics of science. In following the course
of his researches, we shall see another illustration of
the influence of environment on mental tendencies,
and mark how the sea-shores and mountains, the
James Hut ton 281
glens and lowlands of Scotland have given form and
colour to the development of geological theory.
James Hutton (1726-1797) was born in Edinburgh
on the 3rd June 1726, and was educated at the High
School and University of that city. 1 His father, a
worthy citizen there, had held the office of City
Treasurer, but died while the son was still young,
to whom he left a small landed property in Berwick-
shire. While attending the logic lectures at the
University, Hutton's attention was arrested by a
reference to the fact that, although a single acid
suffices to dissolve the baser metals, two acids must
combine their strength to effect the solution of gold.
The professor, who had only used this illustration
in unfolding some general doctrine, may or may not
have made his pupil a good logician, but he certainly
made him a chemist, for from that time the young
student was drawn to chemistry by a force that
only became stronger as years went on. When at
seventeen years of age he had to select his profession
in life, he was placed as an apprentice in a lawyer's
office. But genius is irrepressible, and amid the
drudgery of the law the young clerk's chemistry
not infrequently came to the surface. He would be
found amusing himself and his fellow-apprentices
with chemical experiments, when he should have
been copying papers or studying legal proceedings,
1 For the biographical details in this sketch I am indebted to
the admirable "Biographical Account of Dr. James Hutton" by
his friend and illustrator, Playfair. This was first printed in the
Transactions of the Royal Society of Edinburgh, and will be found
in vol. iv. of Playfair's collected works
282 Hut tons Education and Early Career
so that finally his master, seeing that law was evidently
not his bent, released him from his engagement, and
advised him to seek some other employment more
suited to his turn of mind.
Hutton accordingly, after a year's drudgery at law,
made choice of medicine as the profession most nearly
allied to chemistry, and most likely to allow him to
indulge his predilection for science. For three years
he prosecuted his medical studies at Edinburgh, and
thereafter, as was then the custom, repaired to the
Continent to complete his professional training. He
remained nearly two years in Paris, pursuing there
with ardour the studies of chemistry and anatomy.
Returning to Scotland by way of the Low Countries,
he took the degree of Doctor of Medicine at Leyden
in September 1749.
But the career of a physician seems to have grown
less attractive to him as the time came on for his
definitely settling in life. He may have been to
some extent influenced by the success of certain
chemical researches which he had years before begun
with a friend of kindred tastes researches which
had led to some valuable discoveries in connection
with the nature and production of sal ammoniac, and
which appeared to offer a reasonable prospect of
commercial success. In the end he abandoned all
thought of practising medicine, and resolved to
apply himself to farming. He was a man never
disposed to do things by halves. Having made up
his mind in favour of agriculture as his vocation,
he determined to take advantage of the best practical
instruction in the subject then available. Accordingly
Hut ton as Farmer 283
in 1752 he betook himself to Norfolk, lived with a
Norfolk farmer, and entered with all the zest of a
young man of six-and-twenty into the rural sports
and little adventures which, in the intervals of labour,
formed the amusement of his host and his neighbours.
It appears to have been during this sojourn in East
Anglia that Hutton's mind first definitely turned to
mineralogy and geology. He made many journeys
on foot into different parts of England. In Norfolk
itself there was much to arouse his attention. Every
here and there, the underlying White Chalk came to
the surface, with its rows of fantastically-shaped black
flints. To the east, lay the Crag with its heaps of sea-
shells, stretching over many miles of the interior. To
the north, the sea had cut a range of cliffs in the
Boulder-clay which, with its masses of chalk and its
foreign stones, presented endless puzzles to an
inquirer. To the west, the shores of the Wash
showed the well-marked strata of Red Chalk and Car-
stone, emerging from underneath the White Chalk of
the interior.
Hutton tells, in one of his letters written from
Norfolk, that he had grown fond of studying the
surface of the earth, and was looking with anxious
curiosity into every pit or ditch or bed of a river
that fell in his way.
After spending about two years in Norfolk, he
took a tour into Flanders, with the view of com-
paring the husbandry there with that which he had
been studying in England. But his eyes were now
turned to what lay beneath the crops and their soils,
and he took note of the rocks and minerals of the
284 Hut ton relinquishes Farming
districts through which he passed. At last, about
the end of the summer of 1754, he settled down
on his own paternal acres in Berwickshire, which he
cultivated after the most approved methods. For
fourteen years he remained immersed in rural pur-
suits, coming occasionally to Edinburgh and making,
from time to time, an excursion to some more distant
part of the kingdom. His neighbours in the country
probably looked upon him only as a good farmer, with
more intelligence, enterprise, culture and knowledge
of the world than were usual in their society, and
displaying a playful humour and liveliness of manner
which must have made his companionship extremely
pleasant. Probably not one of the lairds and farmers
in the South of Scotland, who met him at kirk and
market, had the least suspicion that this agreeable
neighbour of theirs was a man of surpassing genius,
who at that very time, amidst all the rural pursuits in
which he seemed to be absorbed, was meditating on
some of the profoundest problems in the history of the
earth, and was gathering materials for such a solution
of these problems as had never before been attempted.
The sal ammoniac manufacture had proved suc-
cessful, and from 1765 Hutton became a regular
co-partner in it. His farm, now brought into excel-
lent order, no longer afforded him the same interest
and occupation, and eventually he availed himself of
an opportunity of letting it to advantage. He deter-
mined about the year 1768 to give up a country life
and establish himself in Edinburgh, in order that, with
uninterrupted leisure, he might devote himself entirely
to scientific pursuits.
Establishes himself in Edinburgh 285
The Scottish capital had not yet begun seriously to
suffer from the centripetal attractions of London. It
was the social centre of Scotland, and retained within
its walls most of the culture and intellect of that ancient
kingdom. Hutton, from his early and close connection
with Edinburgh, had many friends there, and, on his
return for permanent residence, was received at once
into the choicest society of the town. One of his most
intimate associates was Dr. Joseph Black, the famous
chemist to whom we owe the discovery of carbonic
acid. This sympathetic friend took the keenest interest
in Hutton's geological theories, and was able to contri-
bute to their formation and development. Hutton
himself acknowledges that one of his doctrines, that
of the influence of compression in modifying the
action of heat, was suggested by the researches of
Dr. Black. The chemist's calm judgment and exten-
sive knowledge were always at the command of his
more impulsive geological friend, and doubtless
proved of essential service in guiding him in his
speculations.
Another of Hutton's constant and intimate asso-
ciates was John Clerk of Eldon, best known as the
author of a work on naval tactics, and the inventor
of the method of breaking the enemy's line at sea,
which led to so many victories by the fleets of Great
Britain. A third member of his social circle, who
may be alluded to here, was the philosopher and
historian Adam Ferguson, a man of remarkable force
of character, who, to his various literary works, which
were translated into French and German, added the
distinction of a diplomatist, for in 1778-1779 he acted
286 Hut ton's versatility
as Secretary of the Commission sent across the Atlantic
by Lord North to try to arrange the matters in dispute
between the mother country and her North American
colonies.
When Hutton found himself in these congenial
surroundings, with ample leisure at his command,
he appears to have turned at once to his first love
in science, by betaking himself to chemical experi-
ment. Even without the testimony of his biographer,
we have only to look at his published works to be
impressed by his unwearied industry, and by the extra-
ordinarily wide range of his studies. Though up to
the time of his settling in Edinburgh he had published
nothing, he had read extensively. There were hardly
any of the sciences, except the mathematical, to which
he did not turn his attention. He was a diligent
reader of voyages, travels and books of natural history,
carefully storing up the facts which seemed to him to
bear on the problems of the earth's history. He not
only prosecuted chemistry and mineralogy, but dis-
tinguished himself as a practical meteorologist by his
important contribution to the theory of rain. He
wrote a general system of physics and metaphysics in
one quarto volume, and no fewer than three massive
quartos were devoted by him to An Investigation of
the Principles of Knowledge, and of the Progress of Reason
from Sense to Science and Philosophy. At the time of
his death he was engaged upon a treatise on the
Elements of Agriculture.
Hutton was thus no narrow specialist, wrapped
up in the pursuit of one circumscribed section of
human inquiry. His mind ranged far and wide
His geological environment 287
over many departments of knowledge. He took
the keenest interest in them all, and showed the
most vivid sympathy in their advancement. His
pleasure in every onward step made by science and
philosophy showed itself in the most lively demonstra-
tions. " He would rejoice," we are told by Playfair,
" over Watt's improvements on the steam-engine, or
Cook's discoveries in the South Seas, with all the
warmth of a man who was to share in the honour
or the profit about to accrue from them. The fire
of his expression, on such occasions, and the anima-
tion of his countenance and manner, are not to be
described ; they were always seen with great delight
by those who could enter into his sentiments ; and
often with great astonishment by those who could not."
While so much was congenial to his mental habits
in the friendly intercourse of Edinburgh society, there
was not less in the scenery around the city that would
stimulate his geological proclivities. He could not
take a walk in any direction without meeting with
illustrations of some of the problems for the solution of
which he was seeking. If he turned eastward, Arthur's
Seat and Salisbury Crags rose in front of him, with
their memorials of ancient volcanic eruptions. If he
strolled westward, the ravines of the Water of Leith
presented him with proofs of the erosive power of
running water, and with sections of the successive sea-
bottoms of the Carboniferous period. Even within the
walls of the city, the precipitous Castle Rock bore
witness to the energy with which in ancient times
molten material had been thrust into the crust of the
earth.
a88 Huttoris elaboration of his Theory
No more admirable environment could possibly have
inspired a geologist than that in which Hutton now
began to work more sedulously at the study of the
former changes of the earth's surface. But he went far
afield in search of facts, and to test his interpretation
of them. He made journeys into different parts of
Scotland, where the phenomena which engaged his
attention seemed most likely to be well displayed. He
extended his excursions likewise into England and
Wales. For about thirty years, he had never ceased
to study the natural history of the globe, constantly
seeking to recognise the proofs of ancient terrestrial
revolutions, and to learn by what causes they had been
produced. He had been led to form a definite theory
or system which, by uniting and connecting the scattered
facts, furnished an intelligible explanation of them.
But he refrained from publishing it to the world. He
had communicated his views to one or two of his
friends, perhaps only to Dr. Black and Mr. Clerk,
whose judgment and approval were warmly given to
him. The world, however, might have had still a long
time to wait for the appearance of his dissertation, had
it not been for the interest that he took in the founda-
tion of the Royal Society of Edinburgh, which was
incorporated by Royal Charter in I783. 1 At one of
x The Royal Society had been preceded by the Philosophical
Society, out of which it sprang. Edinburgh at that time was famous
for the number of its clubs and convivial meetings, at some of which
Black and Hutton were constant companions. Various anecdotes
have been handed down of these two worthies and their intercourse,
of which the following may suffice as a specimen. "These attached
friends agreed in their opposition to the usual vulgar prejudices, and
frequently discoursed together upon the absurdity of many generally
Hut tons ' Theory of the Earth ' 289
the early meetings of this Society he communicated a
concise account of his Theory of the Earth, which
appeared in the first volume of the Transactions. This
essay was afterwards expanded, with much ampler
details of observations and fuller application of principles
to the elucidation of the phenomena, and the enlarged
work appeared in two octavo volumes in the year 1795
with the title of Theory of the Earth, with Proofs and
received opinions, especially in regard to diet. On one occasion
they had a disquisition upon the inconsistency of abstaining from
feeding on the testaceous creatures of the land, while those of the
sea were considered as delicacies. Snails, for instance why not use
them as articles of food ? They were well known to be nutritious
and wholesome even sanative in some cases. The epicures, in
olden time, esteemed as a most delicious treat the snails fed in the
marble quarries of Lucca. The Italians still hold them in esteem.
The two philosophers, perfectly satisfied that their countrymen
were acting most absurdly in not making snails an ordinary article
of food, resolved themselves to set an example ; and accordingly,
having procured a number, caused them to be stewed for dinner.
No guests were invited to the banquet. The snails were in due
season served up ; but, alas ! great is the difference between theory
and practice so far from exciting the appetite, the smoking dish
acted in a diametrically opposite manner, and neither party felt
much inclination to partake of its contents. Nevertheless, if they
looked on the snails with disgust, they retained their awe for
each other ; so that each conceiving the symptoms of internal revolt
peculiar to himself, began, with infinite exertion to swallow in
very small quantities the mess which he internally loathed. Dr.
Black at length broke the ice, but in a delicate manner, as if to
sound the opinion of his messmate, ' Doctor, do you not think
that they taste a little a very little queer ? ' 4 D queer,
D - queer, indeed ; tak them awa', tak them awa' ! ' vociferated
Dr. Hutton, starting up from table and giving full vent to
his feelings of abhorrence." A Series of Original Portraits, by John
Kay (commonly known as Kay's Edinburgh Portraits), vol. i. p. 57.
T
290 James Hut ton
Illustrations. After Hutton's death his friend Playfair
published in 1802 his classical Illustrations of the
Huttonian Theory. We are thus in possession of ample
information of the theoretical views adopted by Hutton,
and of the facts on which he based them. Before
considering these, however, it may be convenient to
follow the recorded incidents of his quiet and unevent-
ful life, that we may the better understand the manner
in which he worked, and the nature of the material by
which he tested and supported his conclusions.
It was one of the fundamental doctrines of Hutton's
system that the internal heat of the globe has in past
time shown its vigour by the intrusion of large masses
of molten material into the crust. He found many
examples of these operations on a small scale in the
neighbourhood of Edinburgh and in the lowlands of
Scotland. But he conceived that the same effects had
been produced in a far more colossal manner by the
protusion of large bodies of granite. This rock, which
Werner had so dogmatically affirmed to be the earliest
chemical precipitate from his primeval ocean, was
surmised by Hutton to be of igneous origin, and he
believed that, if its junctions with the surrounding
strata were examined, they would be found to furnish
proofs of the correctness of his inference. The
question could be easily tested in Scotland, where, both
in the Highlands and among the Southern Uplands,
large bodies of granite had long been known to form
important groups of mountains. Accordingly, during
a series of years, Hutton undertook a number of excur-
sions into various parts of his native country, and
returned from each of them laden with fresh illus-
Excursions in Scotland 291
trations of the truth of the conclusions at which he had
arrived. At one time he was busy among the roots of
the Grampian Hills, at another he was to be seen
scouring the lonely moorlands of Galloway, or climbing
the precipices and glens of Arran. His visit to Glen
Tilt has been made memorable by Playfair's brief
account of it. 1 He had conjectured that in the bed of
the river Tilt actual demonstration might be found
that the Highland granite has disrupted the surround-
ing schists. Playfair describes how " no less than six
large veins of red granite were seen in the course of a
mile, traversing the black micaceous schistus, and
producing, by the contrast of colour, an effect that
might be striking even to an unskilful observer. The
sight of objects which verified at once so many impor-
tant conclusions in his system, filled him with delight ;
and as his feelings, on such occasions, were always
strongly expressed, the guides who accompanied him
were convinced that it must be nothing less than
the discovery of a vein of silver or gold that could
call forth such strong marks of joy and exultation."
Another of Hutton's fundamental generalisations
was tested in as vivid and successful a manner. He
taught that the ruins of an earlier world lie beneath
the secondary strata, and that where the base of these
strata can be seen, it will be found to reveal, by what
is now known as an unconformability, its relation
to the older rocks. He had at various points in Scot-
land satisfied himself by actual observation that this
relation holds good. But he determined to verify it
1 Hutton's account is in the portion of the third volume of his
Theory referred to in a note on p 297.
292 Hut ton, Hall and Play fair
once more by examining the junction of the two
groups of rock along (the coast where the range of
the Lammermuir Hills 'plunges into the sea. Accom-
panied by his friend Sir James Hall, whose property
of Dunglass lay in the immediate neighbourhood, and
by his colleague and future biographer, Playfair, and
favoured with calm weather, he boated along these
picturesque shores until the unconformable junction
was reached. The vertical Silurian shales and grits
were found to protrude through, and to be wrapped
round by, the red sandstone and breccia. " Dr.
Hutton," Playfair writes, " was highly pleased with
appearances that set in so clear a light the different
formations of the parts which compose the exterior
crust of the earth, and where all the circumstances
were combined that could render the observation
satisfactory and precise. On us who saw these pheno-
mena for the first time, the impression made will not
easily be forgotten. The palpable evidence presented
to us of one of the most extraordinary and important
facts in the natural history of the earth, gave a reality
and substance to those theoretical speculations which,
however probable, had never till now been directly
authenticated by the testimony of the senses. We
often said to ourselves, what clearer evidence could
we have had of the different formation of these rocks,
and of the long interval which separated their forma-
tion, had we actually seen them emerging from the
bosom of the deep ? . . . The mind seemed to grow
giddy by looking so far into the abyss of time ; and
while we listened with earnestness and admiration to
the philosopher who was now unfolding to us the
Hut tons person and mode of life 293
order and series of these wonderful events, we became
sensible how much further reason may sometimes go
than imagination can venture to follow."
Hutton's lithe active body betokened the unwearied
vigour of his mind. His high forehead, firmly
moulded features, keen observant eyes, and well-
shaped, rather aquiline nose, marked him out at once
as a man of strong intellect, while the gentleness that
beamed in his face was a reflex of the kindliness of
his nature. His plain dress, all of one colour, gave
a further indication of the unostentatious simplicity of
his character.
His mode of life was in harmonious keeping with
these personal traits. After working in his study
during the day he would invariably pass the evening
with his friends. " A brighter tint of gaiety and
cheerfulness spread itself over every countenance when
the doctor entered the room ; and the"^ philosopher
who had just descended from the sublimest specula-
tions of metaphysics or risen from the deepest re-
searches of geology, seated himself at the tea-table,
as much disengaged from thought, as cheerful and
gay, as the youngest of the company." His character
was distinguished by its transparent simplicity, its
frank openness, its absence of all that was little or
selfish, and its overflowing enthusiasm and vivacity.
In a company he was always one of the most ani-
mated speakers, his conversation full of ingenious and
original observation, showing wide information, from
which an excellent memory enabled him to draw end-
less illustrations of any subject that might be dis-
cussed, where, "when the subject admitted of it, the
294 Huttoris last illness
witty and the ludicrous never failed to occupy a con-
siderable place."
Though his partnership in the chemical work
brought him considerable wealth, it made no differ-
ence in the quiet unostentatious life of a philosopher,
which he had led ever since he settled in Edinburgh.
A severe attack of illness in the summer of 1793
greatly reduced his strength, and though he recovered
from it and was able to resume his life of activity, a
second attack of the same ailment in the winter of
1796 terminated at last fatally on the 26th March,
1797, when he was in his seventy-first year.
Hutton's claim to rank high among the founders
of geology rests on no wide series of writings, like
those which Von Buch poured forth so copiously for
more than two generations. Nor was it proclaimed
by a host of devoted pupils, like those who spread
abroad the fame of Werner. It is based, so far at
least as geology is concerned, on one single work, 1
and on the elucidations of two friends and disciples.
On the 7th of March and 4th of April, 1785,
Hutton read to the Royal Society of Edinburgh his
Memoir on a " Theory of the Earth ; or an In-
vestigation of the Laws observable in the Com-
position, Dissolution and Restoration of Land upon
the Globe." Extending to no more than 96 quarto
pages, it was written in a quiet, logical manner, with
no attempt at display but with an apparent anxiety
to state the author's opinions as tersely as possible.
1 The first sketch and the expansion of it into two octavo
volumes may be regarded as practically one work, so far as the
originality of conception is concerned.
His literary style 295
Probably no man realised then that this essay would
afterwards be regarded as marking a turning-point in
the history of geology. For some years it remained
without attracting notice from friend or foe. 1
For this neglect various causes have been assigned.
The title of the Memoir was perhaps unfortunate.
The words " Theory of the Earth " suggested still
another repetition of the endless speculations as to
the origin of things, of which men had grown weary.
System after system of this kind of speculation had
been proposed and had dropped into oblivion ; and no
doubt many of his contemporaries believed Hutton's
" Theory " to be one of the same ill-fated brood.
His friend Playfair admits that there were reasons in
the construction of the Memoir itself why it should
not have made its way more speedily into notice.
Its contents were too condensed, and contained too
little explanation of the grounds of the reasoning. Its
style was apt to be prolix and obscure. It appeared,
too, in the Transactions of a learned society which had
only recently been founded, and whose publications were
hardly yet known to the general world of science.
1 It does not appear to be generally known that Desmarest, de-
parting from his usual practice of not noticing the work of living
writers, wrote a long and careful notice of Hutton's Memoir of
1785 in the first volume of his Geographic Physique, published in
1794-1795. He disagrees with many of Hutton's views, such, for
instance, as that of the igneous origin of granite. But he
generously insists on the value of the observations with which the
Scottish writer had enriched the natural history of the earth and
the physical geography of Scotland. " It is to Scotland," he says,
"that Hutton's opponent must go to amend his results and sub-
stitute for them a more rational explanation" (p. 75)-
296 Hut ton's Opponents
At last, after an interval of some five years, De
Luc assailed the " Theory " in a series of letters in
the Monthly Review for 1790 and 1791. So far as
we know, Hutton published no immediate reply to
these attacks. He had often been urged by his
friends to publish his entire work on the Theory of
the Earth, with all the proofs and illustrations which
had been accumulating in his hands for so many
years. He delayed the task, however, until, during
the convalescence from his first severe illness, he re-
ceived a copy of a strenuous attack upon his system
and its tendencies by Richard Kirwan, a well-known
Irish chemist and mineralogist of that day. 1
This assailant not only misconceived and misrepre-
sented the views which he criticized, but charged
their author with atheistic opinions. Weakened as he
was by illness, Hutton, with characteristic energy, the
very day after he received Kirwan's paper, began the
revision of his manuscript, and worked at it until he
was able to send it to the press. It appeared in
1795, tnat i s > ten 7 e ars after the first sketch of the
subject had been given to the Royal Society of Edin-
burgh. Besides embodying that sketch, it gave a
much fuller statement of his conclusions, and an
ampler presentation of the facts and observations on
which they were founded. It formed two octavo
volumes. Playfair tells us that a third volume,
1 " Examination of the Supposed Origin of Stony Substances,"
read to the Royal Irish Academy, 3rd February, 1793, and pub-
lished in vol. v. of their Transactions, p. 51. For a crushing
exposure of Kirwan's mode of attack see Playfair's Illustrations of
the Huttonian Theory, 119, 418.
Play f air's t Illustrations ' 297
necessary for the completion of the work, remained
in manuscript. 1
If Hutton's original sketch was defective in style
and arrangement, his larger work was even more
unfortunate in these respects. Its prolixity deterred
readers from its perusal. Yet it is a vast storehouse
of acute and accurate observation and luminous de-
duction, and it deserves to be carefully studied by
every geologist who wishes to comprehend the history
of his own science.
Fortunately for Hutton's fame and for the onward
march of geology, the philosopher numbered among
his friends the illustrious mathematician and natural
philosopher, John Playfair (1748-1819), who had been
closely associated with him in his later years, and was
intimately conversant with his geological opinions.
Gifted with a clear penetrating mind, a rare faculty
of orderly logical arrangement, and an English style
of altogether remarkable precision and elegance, he
was of all men best fitted to let the world know
what it owed to Hutton. Accordingly, after his
friend's death, he determined to prepare a more
popular and perspicuous account of Hutton's labours.
He gave in this work, first a clear statement of the
essential principles of Hutton's system, and then a
series of notes or essays upon different parts of the
J A portion of this precious manuscript containing six chapters
(iv.-ix.) came into the possession of Leonard Homer, F.R.S., who
presented it to the Geological Society of London. It remained
hardly noticed in the library of the Society until 1899, when at
my solicitation the Society printed and published it. This is the
only portion of the MS. now known to exist.
298 Play fairs 'Illustrations'
system, combining in these a large amount of original
observation and reflection of his own. His volume
appeared in the spring of 1802, just five years after
Hutton's death, with the title of Illustrations of the
Huttonian Theory of the Earth. Of this great classic
it is impossible to speak too highly. After the lapse
of a century it may be read with as much profit and
pleasure as when it first appeared. For precision of
statement and felicity of language it has no superior
in English scientific literature. To its early inspira-
tion I owe a debt which I can never fully repay.
Upon every young student of geology I would im-
press the advantage of reading and re-reading, and
reading yet again this consummate masterpiece. How
different would geological literature be to-day if men
had tried to think and write like Playfair !
There are thus three sources of information as to
Hutton's geological system his first sketch of 1785,
his two octavo volumes of 1795, w ^ tn tne portion of
the third volume published in 1899 and Playfair's
Illustrations of I8O2. 1 Let us now consider what were
his fundamental doctrines.
Although he called his system a Theory of the
Earth, Hutton's conceptions entirely differed from
those of the older cosmogonists, who thought them-
selves bound to begin by explaining the origin of
things, and who proceeded on a foundation of hypo-
thesis to erect a more or less fantastic edifice of mere
speculation. He, on the contrary, believed that it is
1 To these may be added the memoirs by Sir James Hall
which appeared after Hutton's death and from which some
interesting particulars may be gleaned as to the master's opinions.
Hut ton's ' Theory of the Earth ' 299
the duty of science first to try to ascertain what evi-
dence there is in the earth itself that will throw light
upon the history of the planet. Instead of invoking
conjecture and hypothesis, he proceeded from the
very outset to collect the actual facts, and to marshall
these in such a way as to make them tell their own
story. Unlike Werner, he had no preconceived theory
about the origin of rocks, with which all the pheno-
mena of nature had to be made to agree. His theory
grew so naturally out of his observations that it
involved no speculation in regard to a large part
of its subject.
Hutton started with the grand conception that the
past history of our globe must be explained by what
can be seen to be happening now, or to have happened
only recently. The dominant idea in his philosophy is
that the present is the key to the past. We have
grown so familiar with this idea, it enters so intimately
into all our conceptions in regard to geological ques-
tions, that we do not readily realise the genius of
the man who first grasped it with unerring insight,
and made it the chief corner-stone of modern geology.
From the time of his youthful rambles in Norfolk,
Hutton had been struck with the universal proofs
that the surface of the earth has not always been as
it is to-day. Everywhere below the covering of soil
he found evidence of former conditions, entirely unlike
those visible now. In the great majority of cases,
he noticed that the rocks there to be seen consist of
strata, disposed in orderly arrangement parallel with
each other. Some of these strata are formed of
pudding-stone, others of sandstone, of shale, of lime-
300 James Hut ton
stone, and so forth, differing in many respects from
each other, but agreeing in one essential character,
that they are composed of fragmentary or detrital
material, derived from rocks older than themselves.
He saw that these various strata could be exactly
paralleled among the accumulations now taking place
under the sea. The pudding-stones were, in his eyes,
only compacted gravels, the sandstones were indurated
sand, the limestones were in great part derived from
the aggregation of the remains of marine calcareous
organisms, the shales from the consolidation of mud
and silt. The wide extent of these strata, forming,
as they do, most of the dry land, seemed to him to
point to the sea as the only large expanse of water
in which they could have been deposited.
Thus corroborating the deductions of previous
observers, the first conclusion of the Scottish philo-
sopher was that the greater part of the land consists
of compacted sediment which, worn away from some
pre-existing continents, was spread out in strata over
the bed of the sea. He realised that the rocks thus
formed are not all of the same age, but, on the
contrary, bear witness to a succession of revolutions.
He acknowledged the existence of a series of ancient
rocks which he called Primary, not that he believed
them to be the original or first-formed rocks in the
structure of the planet, but that they were the oldest
that had then been discovered. They included the
various schists and slates which Werner claimed as
chemical precipitates, but in which Hutton could only
see the hardened and altered mechanical sediments of a
former ocean. Above them, and partly formed out of
His mews on Consolidation of Strata 301
them, came the Secondary strata that constitute the
greater part of the land.
But all these sedimentary deposits have passed from
their original soft condition into that of solid stone.
Hutton attributed this change to the action of sub-
terranean heat. In his day, the chemistry of geology
was exceedingly imperfect, though in Hutton's hands
it was greatly less erroneous than in those of Werner.
The solubility of silica, for instance, and its capacity
for being introduced in aqueous solution into the
minutest crevices and pores of a rock, were not known.
It need not, therefore, surprise us to find that in
the Huttonian conception the flints in chalk were
injected into the rock in a molten state, and that
the agate of fossil wood bore marks of igneous fusion.
Hutton did not realise to what an extent mere
compression could solidify the materials of sedimentary
strata, nor how much may be done, by infiltration
and deposition between the clastic grains, towards
converting originally loose detritus into the most
compact kind of stone. But there was one kind of
compression which though not perhaps at first obvious,
was clearly perceived by him in its geological relations.
Following out ideas suggested to him by Black, he
saw that the influence of heat upon rocks must be
largely modified by pressure. The more volatile com-
ponents, which would be speedily driven off by a
high temperature at the surface of the earth, might
be retained under great pressure below that surface.
Hutton conceived that limestone might even be fused
in this way, and yet still keep its carbonic acid. This
idea was ridiculed at the time, but its truth was
302 James Hut ton
confirmed afterwards by Hall's experiments, to which
I shall allude in the sequel.
The next step in Hutton's reasoning was that
whereby he sought to account for the present position
of the strata which, originally deposited under the sea,
are now found even on mountain-crests 15,000 feet
above sea-level. We have seen how Werner looked on
his vertical primitive strata as having been precipitated
from solution in that position, and as having been
uncovered by the gradual subsidence and disappearance
of the water. Hutton attacked the problem in a
different fashion. He saw that if the exposure of
the dry land had been due merely to the subsidence
of the sea, it would involve no change in the positions
of the strata relatively to each other. What were
first deposited should lie at the bottom, what were
last deposited, at the top ; and the whole should retain
their original flatness.
But the most cursory examination was, in his
opinion, sufficient to show that the actual conditions in
nature were entirely different from any such arrange-
ment. Wherever he went, he found, as Steno had
done, proofs that the sedimentary strata, now forming
most of the land, had in large measure lost the
horizontal or gently inclined position in which sedi-
mentary deposits are normally accumulated. He saw
them often inclined, sometimes placed on end, or even
stupendously contorted and ruptured. It was mani-
festly absurd, as De Saussure had shown in the Alps,
to suppose that pebbles in vertical beds of con-
glomerate could ever have been deposited in such
positions. And if some of the vertical strata could thus
On Disturbance of Strata 303
be demonstrated to have been originally horizontal or
nearly so, there could be no reason for refusing to con-
cede that the same alteration had happened to the other
vertical strata, even although they might not afford
such obvious and convincing proofs of it. As Steno
had long before pointed out, no stratum could have
ended off abruptly at the time of its formation, unless
against a cliff or slope that arrested its detrital materials
from drifting further, nor could it have been accumu-
lated in plicated layers. But nothing is more common
than to find strata presenting their truncated ends to
the sky, while in some districts they are folded and
crumpled, like piles of carpets. Not only so, but
again and again, they are found to be sharply dis-
located, so that two totally different series are placed
parallel to each other.
Hutton recognised that these changes, which were
probably brought about at different periods, must be
attributed to some great convulsions which, from time
to time, have shaken the very foundations of the earth.
He could prove that, in some places, the Primary rocks
had in this way been broken up and placed on end
before the Secondary series was laid down, for, as on
the Berwickshire Coast, he had traced the older vertical
strata overlain and wrapped round by the younger hori-
zontal deposits, and had also observed, from the well-
worn fragments of the former enclosed in the latter,
that the interval of time represented by the break
between them must have been of considerable duration.
Having been led by this train of observation and
deduction, to the demonstration of former gigantic
disturbances, by which the bed of the sea had been
304 James Hittton
upheaved and its hardened sediments had been tilted,
plicated and fractured, in order to form the existing
dry land, Hutton had next to look round for some
probable cause for these phenomena. He inferred
that the convulsions could only have been produced
by some force that acted from below upward, but was
so combined with the gravity and resistance of the
mass to which it was applied, as to create a lateral
and oblique thrust that gave rise to the contortions
of the strata. He did not pretend to be able to
explain the nature and operation of this subterranean
force, though he believed it to be essentially due to
the effects of heat. Far from sharing the ancient
misconception that volcanoes are due to the combus-
tion of inflammable substances, he connected them with
the high internal temperature of the globe, and regarded
them as " spiracles to the subterranean furnace in order
to prevent the unnecessary elevation of land, and fatal
effects of earthquakes/' 1
Unlike Werner, Hutton saw that while no mere
combustion of inflammable substances could account
for this high temperature of the subterranean regions,
the actual conditions involved must be so far different
from ordinary combustion as not improbably to require
no circulation of air, nor any supply of carbonaceous
or other materials as fuel. The nucleus of the globe
might accordingly "be a fluid mass, melted, but
unchanged by the action of heat."
In this way, appealing at every step to the actual
facts of nature, Hutton built up the first part of his
1 Theory of the Earth, vol. i. p. 146. It will be remembered that
a similar opinion was expressed by Strabo.
On Intrusive Rocks 305
immortal Theory. Most of the facts cited by him
were more or less familiar to men ; and some of the
obvious inferences to be drawn from them had been
deduced by other observers before his time. But no
one until then had grouped them into a coherent
system by which the earth became, as it were, 1 her
own interpreter. The very obviousness and familiarity
of his doctrine at the present time, when it has become
the groundwork of modern geology, are apt to blind
us to the genius of the man who first conceived it,
and worked it into a harmonious and luminous whole.
In the course of his journeys in Scotland, Hutton
had come upon many examples of rocks that were not
stratified. Some of these occurred among the Primary
masses ; others were observable in the Secondary series.
Reflecting on the probable reaction of the heated
interior of the globe upon its outer cooler shell or
crust, he had come to the conclusion that many, if
not all, of these unstratified rocks were to be regarded
as material that had once been in a molten condition,
and had been injected from below during some of
the great convulsions indicated by the disturbed strata.
He distinguished three principal kinds of such intrusive
rocks " Whinstone," under which term he included a
miscellaneous series of dark, heavy, somewhat basic
rocks, now known as dolerites, basalts, diabases and
andesites ; Porphyry, which probably comprised such
rocks as felsite, orthophyre and quartz-porphyry ; and
Granite, which, though the term was generally used
by him in its modern sense, embraced some rocks of
more basic character.
He showed that the whinstones correspond so
306 James Hut ton
closely to modern lavas in structure and composition,
that they may be regarded as probably also of volcanic
origin. But, as was discussed in Chapter VIII. (p. 259),
he did not suppose that they had actually been erupted
at the surface, like streams of lava. He found them
to occur sometimes in vertical veins, known in Scot-
land as dykes, a term now universal in English geolo-
gical literature, and sometimes as irregular bosses, or
interposed as sheets between the strata. He believed
these rocks to be masses of subterranean or unerupted
lava, but as we have seen, the grounds on which he
reached this conclusion were not always such as the sub-
sequent progress of inquiry has justified. The deduc-
tion was itself in many cases correct, but the reasoning
that led up to it, was partly fallacious. Hutton argued,
for instance, that the carbonate of lime, so commonly
observable in his " Whinstones " indicated that the
rock had been fused deep within the earth, under
such pressure as to keep that mineral in a molten
state, without the loss of its carbonic acid. Like
other mineralogists of his day, he was not aware that
the calcite of the amygdales has been subsequently
introduced in aqueous solution into the steam-cavities,
and that the diffused lime-carbonate in the body of
the rocks generally results from their partial decom-
position by infiltrating water. Much more accurate
were his observations that whinstone has greatly indu-
rated the strata into which it has been injected, even
involving and fusing fragments of them, and reducing
carbonaceous substances, such as coal, to the condition
of coke or charcoal ; that it has sometimes been
intruded among the strata with such violence as to
On Whinstone and Granite 307
shift, upraise, bend and otherwise disturb them, and
that it can be seen to have been thrust abruptly into
one continuous succession of strata, which, above and
below it, are exactly alike, and have obviously been at
one time in contact with each other.
Granite, as Hutton pointed out, differs in many
important respects from " whinstone," more par-
ticularly in its position, for it was then believed to
lie beneath all the known rocks, rising to higher
elevations and sinking to greater depths than any
other material in the crust of the earth. Yet though
he admitted its infraposition, he differed from the
Neptunists in regard to its relative antiquity. He
believed it to be younger than the strata which rest
upon it, for he regarded it as a mass that had once
been melted and had been intruded among the rocks
with which it is now found associated. He supported
this conclusion by various arguments, chief among
which was one based on the occurrence of veins that
diverge from the granite and ramify through the sur-
rounding rocks, diminishing in width as they recede
from their parent mass (p. 291).
Properly to appreciate the value of these doctrines
in regard to the development of a sound geological
philosophy, we must bear in mind what were the
prevalent views entertained on the subject when
Hutton worked out his theory. We have seen that
granite, generally regarded as an aqueous formation,
was affirmed by Werner to have been the first pre-
cipitate that fell to the bottom from his universal
ocean. H. B. De Saussure, who had seen more of
granite and its relations to other rocks than Werner, or
308 James Hut ton
indeed than any other geologist of his time, remained
up to the last a firm believer in the aqueous origin of
that rock. Even after the death of the great Swiss
geologist, Cuvier, sharing his opinions on these
matters, proclaimed as late as the year 1810 his
belief that De Saussure overthrew the doctrine of
central fire, or of a source of heat within the earth's
interior, demonstrated granite to be the oldest rock,
and proved it to have been formed in strata that
were deposited in water. 1 Nobody before Hutton's
time had been bold enough to imagine a series of
subterranean intrusions of molten matter. Those who
adopted his opinion on this subject were styled
Plutonists, and were looked upon as carrying out the
Vulcanist doctrines to still greater extravagance, " attri-
buting to the action of fire widely-diffused rocks which
nobody had till then ever dreamt of removing from
the domain of water." 2
According to the Huttonian theory, fissures and
openings which have from time to time arisen in the
external crust of the earth have reached down to the
intensely hot nucleus. Up these rents the molten
material has ascended, forming veins of whinstone
underground, and, where it has reached the surface,
issuing there in the form of lava and the other
phenomena of volcanoes. Every geologist recognises
these generalisations as part of the familiar teachings
of modern geology.
We have seen that Werner made no distinction,
as regards origin, between what we now call mineral-
1 Cuvier, " liloge de De Saussure," Eloges, i. p. 427.
2 Cuvier, Op. cit. ii. p. 363.
On Mineral Veins 309
veins and the dykes and veins of granite, basalt or
other eruptive rocks. He looked upon them all as
the results of chemical precipitation from an ocean
that covered the rocks in which fissures had been
formed. Hutton, in like manner, drew no line be-
tween the same two well-marked series of veins, but
regarded them all as formed by the introduction of
igneous material. Though more logical than Werner,
he was, as we now know, entirely in error in confound-
ing under one denomination two totally distinct assem-
blages of mineral matter. Werner correctly referred
veins of ores and spars to deposition from aqueous
solution, but was completely mistaken in attributing
the same origin to veins of massive rock. Hutton,
on the other hand, went as far astray in regard to
his explanation of mineral veins, but he made an
important contribution to science in his insistence upon
the truly intrusive nature of veins of granite and
whinstone.
There was another point of difference between the
views of Werner and of Hutton in regard to mineral
veins. One of the undoubted services of the Freiberg
professor was his clear demonstration than veins could
be classified according to their directions, that this
arrangement often sufficed to separate them also
according to age and material, those running along
one parallel, and containing one group of minerals,
being intersected by, and therefore older than, another
series following a different direction, and consisting of
other metals and vein-stones. This important dis-
tinction found no place in Hutton's system. To him
it was enough that he was able to show that certain
310 James H^ltton
veins known to him were intrusive masses of igneous
origin. 1
In the Huttonian theory we find the germ of the
Lyellian doctrine of metamorphism. Hutton, having
demonstrated that granite is not an aqueous but an
igneous rock, further showed that the u Alpine schis-
tus," (which included sandstones, shales and slates, as
well as crystalline schists), being stratified, could not
be original or primitive, but had been deposited like
recent sediments, and had been invaded and altered
by the granite. A passage from his chapter, "On the
Primary Part of the Present Earth " may be quoted
in illustration of the sagacity of his judgment on this
subject : u If, in examining our land, we shall find a
mass of matter which had been evidently formed
originally in the ordinary manner of stratification, but
which is now extremely distorted in its structure and
displaced in its position, which is also extremely
consolidated in its mass and variously changed in its
composition, which, therefore, has the marks of its
original or marine composition extremely obliterated,
and many subsequent veins of melted mineral matter
interjected, we should then have reason to suppose
that here were masses of matter which, though not
different in their origin from those that are gradually
deposited at the bottom of the ocean, have been
more acted upon by subterranean heat and the ex-
1 In Playfair's Illustrations, however, the successive origin of mineral
veins is distinctly affirmed, 226. Reference is there made to the
coincidence between the prevalent direction of the principal Cornish
veins and the general strike of the strata, and to the intersection of
these by the cross-courses at nearly right angles.
On the universality of Denudation 3 1 1
panding power, that is to say, have been changed in
a greater degree by the operations of the mineral king-
dom/' 1 Hutton here compresses into a single, though
somewhat cumbrous, sentence the doctrine to which
Lyell in later years gave the name of metamorphism.
Hutton's vision not only reached far back into the
geological past, it stretched into the illimitable future,
and it embraced also a marvellously broad yet minute
survey of the present. From his early youth he had
been struck with the evidence of incessant decay upon
the surface of the dry land. With admirable insight
he kept hold of this cardinal fact, and followed it
fearlessly from mountain-top to sea-shore. Wherever
we may go, on each variety of rock, in every kind
of climate, the doom of dissolution seemed to him to
be written in ineffaceable characters upon the whole
surface of the dry land. No sooner was the bed of
the ocean heaved up into mountains, than the new
terrestrial surface began to be attacked. Chemical
and mechanical agents were recognised as concerned
in this disintegration, though the precise nature and
extent of their several operations had not then been
studied. The general result produced by them, how-
ever, was never appreciated by any observer more
clearly than by Hutton. From the coast, worn into
stack and skerry and cave, by the ceaseless grinding
of the waves, he had followed the progress of cor-
rosion up to the crests of his Scottish hills. No
rock, even the hardest, could escape, though some
resisted more stubbornly than others.
1 Theory of the Earth, vol. i. pp. 375, 376. This passage may serve
also as an illustration of Hutton's peculiar style of composition.
312 James Hutton
The universality of this terrestrial waste had been
more or less distinctly perceived by other writers, as
has been pointed out in previous pages. But Hutton
saw a meaning in it which no one before him had
so vividly realised. To his eye, while the whole land
undergoes loss, it is along certain lines traced by
running water that this loss reaches its greatest
amount. In the channels of the streams that carry
off the drainage of the land he recognised the results
of a constant erosion of the rocks by the water
flowing over them. As the generalisation was beauti-
fully expressed by Play fair : " Every river appears to
consist of a main trunk, fed from a variety of
branches, each running in a valley proportioned to
its size, and all of them together forming a system
of valleys, communicating with one another, and
having such a nice adjustment of their declivities, that
none of them join the principal valley, either on too
high or too low a level, a circumstance which would
be infinitely improbable if each of these valleys were
not the work of the stream that flows in it.
" If, indeed, a river consisted of a single stream
without branches, running in a straight valley, it
might be supposed that some great concussion, or
some powerful torrent, had opened at once the
channel by which its waters are conducted to the
ocean ; but, when the usual form of a river is con-
sidered, the trunk divided into many branches, which
rise at a great distance from one another, and these
again subdivided into an infinity of smaller ramifica-
tions, it becomes strongly impressed upon the mind
that all these channels have been cut by the waters
On excavation of Valleys 313
themselves ; that they have been slowly dug out by
the washing and erosion of the land ; and that it is
by the repeated touches of the same instrument that
this curious assemblage of lines has been engraved so
deeply on the surface of the globe." 1
The whole of the modern doctrine of earth-
sculpture is to be found in the Huttonian theory.
We shall better appreciate the sagacity and prescience
of Hutton and Playfair, if we remember that their
views on this subject were in their lifetime, and for
many years afterwards, ignored or explicitly rejected,
even by those who accepted the rest of their teaching.
Hall, their friend and associate, could not share their
opinions on this subject. Lyell too, who adopted so
much of the Huttonian theory and became the great
prophet of the Uniformitarian school, never would
admit the truth of Hutton's doctrine concerning the
origin of valleys. Nor even now is that doctrine uni-
versally accepted. It was Jukes who in 1862 revived
an interest in the subject, by showing how completely
the valley system in the south of Ireland was due to
the action of the rivers. 2 Ramsay soon after followed
with further illustrations of the principle. 3 Later
effective support to Hutton's teaching has been given
by the geologists of the United States, who, among
the comparatively undisturbed strata of the Western
^ Illustrations of the Huttonian Theory, p. 102. It will be remembered
that the subaerial excavation of valleys was first demonstrated in ample
detail by Desmarest from Auvergne, and subsequently by De Saussure
from the Alps. The doctrine was afterwards sustained by Lamarck.
See chap. xi.
2 Quart. Journ. GeoL Soc. xviii. (1862).
Physical Geology and Geography of Great Britain , 1863.
James Hut ton
Territories, have demonstrated, by proofs which the
most sceptical must accept, the potency of denudation
in the production of the topography of the land.
To the Huttonian school belongs also the con-
spicuous merit of having been the first to recognise
the potency of glaciers in the transport of detritus
from the mountains. Playfair, in his characteristically
brief and luminous way, proclaimed at the beginning of
last century that " for the removing of large masses
of rock the most powerful engines without doubt which
nature employs are the glaciers, those lakes or rivers
of ice which are formed in the highest valleys of the
Alps, and other mountains of the first order. . . . Be-
fore the valleys were cut out in the form they now
are, and when the mountains were still more elevated,
huge fragments of rock may have been carried to a
great distance ; and it is not wonderful if these same
masses, greatly diminished in size, and reduced to
gravel or sand, have reached the shores or even the
bottom of the ocean." 1 Here the conception of the
former greater extension of the glaciers was fore-
shadowed as a possible or even probable event in
geological history. Yet for half a century or more
after Playfair's time, men were still speculating on the
probability of the transport of the erratics by floating
icebergs during a submergence of Central Europe
under the sea, an hypothesis for which there was
not a particle of evidence. No geologist now ques-
tions the truth of Playfair's suggestion.
In the whole of Hutton's doctrine he rigorously
guarded himself against the admission of any principle
1 Illustrations, p. 388.
On Continuity of Natures operations 3 1 5
which could not be founded on observation. He made
no assumptions. Every step in his deductions was
based upon actual fact, and the facts were so arranged
as to yield naturally and inevitably the conclusion
which he drew from them. Let me quote from the
conclusion of his work a few sentences in illustration of
these statements. In the interpretation of Nature, he
remarks, " no powers are to be employed that are not
natural to the globe, no action to be admitted of except
those of which we know the principle, and no extra-
ordinary events to be alleged in order to explain a
common appearance. The powers of Nature are not
to be employed in order to destroy the very object
of those powers ; we are not to make Nature act
in violation to that order which we actually observe,
and in subversion of that end which is to be perceived
in the system of created things. In whatever manner,
therefore, we are to employ the great agents, fire and
water, for producing those things which appear, it
ought to be in such a way as is consistent with the
propagation of plants and the life of animals upon
the surface of the earth. Chaos and confusion are
not to be introduced into the order of Nature, because
certain things appear to our practical views as being
in some disorder. Nor are we to proceed in feigning
causes when those seem insufficient which occur in our
experience." 1
No geologist ever lived among a more congenial
and helpful group of friends than Hutton. While
they had a profound respect for his genius, they were
drawn towards him by his winning personality, and
1 Theory of the Earth, vol. ii. p. 547.
316 James Hittton
he became the centre of all that was bright, vivacious
and cheerful in that remarkable circle of eminent men.
If he wanted advice and assistance in chemical
questions, there was his bosom-friend Joseph Black,
ever ready to pour out his ample stores of knowledge,
and to test every proposition by the light of his wide
experience and his sober judgement. If he needed
companionship and assistance in his field journeys,
there was the sagacious Clerk of Eldin, willing to
join him, to examine his evidence with judicial
impartiality, and to sketch for him with an artistic
pencil the geological sections on which he laid most
stress. If he felt himself in need of the counsel of
a clear logical intellect, accustomed to consider physical
problems with the precision of a mathematician, there
was the kindly sympathetic Playfair, ever prompt and
pleased to do him a service. With such companions
he discussed his theory in all its bearings. Their
approval was ample enough for his ambition. He
was never tempted to court publicity by frequent
communications to learned societies, or the issue of
independent works treating of his geological observa-
tions and discoveries. But for the establishment of
the Royal Society of Edinburgh, he might have delayed
for years the preparation of the first sketch of his
theory, and had it not been for the virulent attacks
of Kirwan, he might never have been induced to
finish the preparation of his great work. He was a
man absorbed in the investigation of Nature, to whom
personal renown was a matter of utter indifference,
contented and happy in the warm regard and sym-
pathetic appreciation of the friends whom he loved.
CHAPTER X
BIRTH of Experimental Geology. Sir James Hall. Decay of
Wernerianism.
AMONG the friends with whom Hutton associated
in Edinburgh there was one to whom allusion has
already been made, but who demands more special
notice here, seeing that to him a distinguished place
must be assigned among the founders of geology.
To Sir James Hall of Dunglass we owe the establish-
ment of experimental research as a powerful aid in
the investigation and solution of geological problems. 1
Inheriting a baronetcy and a landed estate in East
Lothian, not far from the picturesque cliffs of St.
Abb's Head, and possessed of ample leisure for the
prosecution of intellectual pursuits, he was led to
interest himself in geology. His father, a man of
scientific tastes, became acquainted with Hutton when
the future philosopher was a farmer in the neigh-
bouring county of Berwick. From these early days
Hutton found the hospitality of Dunglass always open
to him. It will be remembered that the famous
J The previous experiments of De Saussure have already been
referred to (ante p. 189) but they were not continued and led
to no satisfactory conclusions.
3 1 8 Sir James Hall
visit to the rocks on the coast at Siccar Point,
described by Playfair, was made with Sir James from
that house.
At first Sir James Hall could not bring himself to
accept Hutton's views. " I was induced," he tells us,
"to reject his system entirely, and should probably
have continued still to do so, with the great majority of
the world, but for my habits of intimacy with the
author, the vivacity and perspicuity of whose conver-
sation formed a striking contrast to the obscurity of
his writings. I was induced by that charm, and by
the numerous original facts which his system had led
him to observe, to listen to his arguments in favour
of opinions which I then looked upon as visionary.
After three years of almost daily warfare with Dr.
Hutton on the subject of his theory, I began to view
his fundamental principles with less and less repug-
nance."
As his objections diminished, Hall's interest in the
details of the system increased. His practical mind
soon perceived that some of the principles, which
Hutton had established by reasoning and analogy,
might be brought to the test of direct experiment.
And he urged his friend to make the attempt, or allow
him to carry out the necessary researches. The proposal
received little encouragement from the philosopher.
Hutton believed that the scale of Nature's processes
was so vast that no imitation of them, on the small
scale of a laboratory, could possibly lead to any reliable
results, or as he afterwards expressed himself in print,
" there are superficial reasoning men who, without
1 Trans. Roy Soc. Edln. vi. (1812), pp. 71-186.
His early Experiments 319
truly knowing what they see, think they know those
regions of the earth which can never be seen, and who
judge of the great operations of the mineral kingdom
from having kindled a fire and looked into the bottom
of a little crucible." 1
Sir James Hall, notwithstanding his veneration for
his master, could not agree with him in this verdict.
He was confirmed in his opinion by an accident which
had occurred at Leith glass-works, where a large mass
of common green glass, that had been allowed to
cool slowly, was found to have lost all the properties
of glass, becoming opaque, white, hard and crystalline.
Yet a piece of this substance, when once more melted
and rapidly cooled, recovered its true vitreous
characters. Hall's shrewd instinct at once applied this
observation to the Huttonian doctrine of the igneous
origin of granite and other rocks. It had been objected
to Hutton's views that the effect of great heat on
rocks was to reduce them to the condition of glass,
but that granite and whinstone, being crystalline
substances, could never possibly have been melted.
Yet here, in this glass-house material, it could be
demonstrated that a thoroughly molten glass could,
by slow cooling, be converted into a crystalline con-
dition, and could be changed once more by fusion
into glass. Hutton had overlooked the possibility
that the results of fusion might be modified by the
rate of cooling, and Hall at once began to test the
matter by experiment. He repeated the process by
which the devitrified glass had been accidentally ob-
tained at the glass-house, and found that he could
1 Theory of the Earth, vol. i. p. 251.
320 Sir James Hall
at will produce, from the same mass of bottle glass,
either a glass or a stony substance, according to the
rate at which he allowed it to cool.
Sir James was too loyal a friend and too devoted
an admirer of the author of the Theory of the Earth
to pursue these researches far during the philosopher's
lifetime. " I considered myself as bound," he tells us,
u in practice to pay deference to his opinion, in a
field which he had already so nobly occupied, and I
abstained during the remainder of his life from the
prosecution of experiments which I had begun in
I790." 1
The death of Hutton in 1797 allowed the laird of
Dunglass to resume the experiments on which he had
been meditating during the intervening years. Select-
ing samples of u whinstones," that is, intrusive dole-
rites and basalts, from the dykes and sills in the
Carboniferous strata around Edinburgh, he reduced
them in the reverberatory furnace of an iron-foundry
to the condition of perfect glass. Portions of this
glass were afterwards re-fused and allowed to cool
very slowly. There was thus obtained " a substance
differing in all respects from glass, and in texture
completely resembling whinstone." This substance
had a distinctly crystalline structure, and Hall gave
it the name of crystallite, which had been suggested
by the chemist, Dr. Hope.
Before he was interested in the defence of the
Huttonian theory, Sir James had made a journey into
1 For Hall's papers see Trans. Roy. Soc. Edin. iii. (1790), p. 8 ; v.
(i79 8 )P-43; vi.(i8i2),p.7i ; vii.(i8i2),pp. 79, 139,169;
P- 3M-
His discovery of Origin of Dykes 321
Italy in the year 1785, visiting Vesuvius, Etna, and
the Lipari Isles, and having for part of the time the
advantage of the company of Dolomieu. He could
not help being much struck with the resemblance
between the lavas of these volcanic regions and the
familiar " whinstones " of his own country. So close
was this resemblance in every respect that he felt
" confident that there was not a lava in Mount Etna
to which a counterpart might not be produced from
the whinstones of Scotland." At Monte Somma
he noted the abundant u vertical lavas " which, in
bands from two to twelve feet broad, run up the old
crater-wall. These bands seemed to him at the time
u to present only an amusing variety in the history
of volcanic eruptions," and, like Dolomieu and Breis-
lak, he looked on them as marking the positions of
rents which, formed in the mountain during former
volcanic explosions, had been filled in from above by
the outflow of lava down the outer fissured surface
of the cone. Subsequent reflection, however, led him
to reconsider this opinion, and to realise that these
" vertical lavas " were " of the utmost consequence in
geology, by supplying an intermediate link between
the external and subterraneous productions of heat.
I now think," he remarks, " that though we judged
rightly in believing those lavas to have flowed in
crevices, we were mistaken as to their direction ; for
instead of flowing downwards, I am convinced they
have flowed upwards, and that the crevices have
performed the office of pipes, through which lateral
explosions have found a vent." He had observed,
also, that the outer margins of some of these dykes,
322 Sir James Hall
in contact with the surrounding rock, were vitreous,
while the central parts presented the ordinary lithoid
texture. This difference, he saw, was fully explained
by his fusion experiments. The lava having risen in a
cold fissure, and having been suddenly chilled along
its outer surface, consolidated there as glass, while
the inner parts, which had cooled more slowly, took
a crystalline structure.
These observations are of historic interest in the
progress of volcanic geology. Hall had sagaciously
found the true interpretation of volcanic dykes, and
he at once proceeded to apply it to the explanation
of the abundant dykes of Scotland. He thus brought
to the support of Hutton's doctrine of the igneous
intrusion of these rocks a new and strong confirma-
tion from the actual crater of a recent volcano.
When engaged upon his fusion experiments with
Scottish whinstones, it occurred to Hall to subject to
the same processes specimens of the lavas which he
had brought from Vesuvius and Etna. The results
which he thus obtained were precisely similar to those
which the rocks from Scotland had yielded. He was
able to demonstrate that lavas may be fused into a
perfect glass, and that this glass, on being re-melted
and allowed to cool gradually, passes into a stony
substance not unlike the original lava. In this
manner, the close agreement between modern lavas
and the ancient basalts of Scotland was clearly proved,
while their identity in chemical composition was
further shown by some analyses made by Dr. Robert
Kennedy. Sir James Hall had thus the satisfaction
of showing that a fresh appeal to direct experiment
His experiments on Compression 323
and observation furnished further powerful support
to some of the disputed doctrines in the theory of
his old friend Hutton. 1
There was another and still more important direc-
tion in which it seemed to this original investigator
that the Huttonian doctrines might be subjected to
the test of experiment. It was an important feature
in these doctrines that the effects of heat upon rocks
must differ very much according to the pressure
under which the heat is applied. Hall argued, like
Hutton, that within the earth's crust the influence of
great compression must retard the fusion of mineral
substances, and retain within them ingredients which,
at the ordinary atmospheric pressure above ground,
are rapidly volatilized. He thus accounted for the
retention of carbonic acid by calcareous rocks, even at
such high temperatures as might melt them. Here
then was a wide but definite field for experiment,
and Hall entered it with the joy of a first pioneer.
As soon as he had done with his whinstone fusions,
he set to work to construct a set of apparatus that
would enable him to subject minerals and rocks to
the highest obtainable temperatures in hermetically
closed tubes. For six or seven years, he continued
his researches, conducting more than 500 ingeniously
devised experiments. He enclosed carbonate of lime
in firmly secured gun-barrels, in porcelain tubes, in
tubes bored through solid iron, and thereafter exposed
it to the highest temperatures which he could obtain.
1 " Experiments on Whinstone and Lava," read before the Royal
Society of Edinburgh 5th March and i8th June 1798, Trans. Roy.
Soc. Edin. vol. v. p. 43.
324 Sir James Hall
He was able to fuse the carbonate without the loss
of its carbonic acid, thus practically demonstrating the
truth of Hutton's contention. He obtained from
pounded chalk a substance closely resembling marble.
Applying these results to the Huttonian theory, he
contended that the effects shown by his experiments
must occur also on a great scale at the roots of
volcanoes ; that subterranean lavas may melt lime-
stone ; that where the molten rock comes in contact
with shell-beds, it may either drive off their car-
bonic acid or convert them into limestone, according
to the heat of the lava and the depth under which
it acts ; and that his experiments enabled him to
pronounce under what conditions the one or the
other of these effects would be produced. He con-
cluded that having succeeded in fusing limestone
under pressure, he could adduce in that single result
" a strong presumption in favour of the solution
which Dr. Hutton has advanced of all the geological
phenomena ; for the truth of the most doubtful
principle which he has assumed has thus been estab-
lished by direct experiment." 1
Hardly less striking were Hall's experiments in
1 " Account of a series of experiments showing the effects of com-
pression in modifying the action of heat," read to the Royal
Society of Edinburgh, 3rd June 1805. Trans. Roy. Soc. Edin. vi.
p. 71. The same ingenious observer subsequently instituted a series
of experiments to imitate the consolidation of strata. By filling an
iron vessel with brine and having layers of sand at the bottom, he was
able to keep the lower portions of the sand at a red heat, while the
brine at the top was not too hot to let the hand be put into it. In
the end the sand at the bottom was found compacted into sandstone.
Op. at. x. (1825), p. 314.
His experiments on Plication 325
illustration of the processes whereby strata, originally
horizontal, have been thrown into plications. His
machine for contorting layers of clay is familiar to
geological students from the illustrations of it given
in text-books. 1 He showed how closely the con-
volutions of the Silurian strata of the Berwickshire
coast could be experimentally imitated by the lateral
compression of layers of clay under considerable
vertical pressure. In this, as in his other applica-
tions of experiment, he led the way, and laid the
foundation on which later observers have built with
such success. 2
There was thus established at Edinburgh a group
of earnest and successful investigators of the history
of the earth, who promulgated a new philosophy of
geology, based upon close observation and carefully
devised experiment. Among these men there was
only one teacher the gentle and eloquent Playfair ;
but his functions at the University were to teach
mathematics and natural philosophy. He had thus
no opportunity of training a school of disciples who
1 Tram. Roy. Soc. Edm. vol. vii. p. 79 and Plate iv. As already
remarked, Hall differed from his master and from Playfair in regard
to their views on the efficacy of subaerial denudation. He preferred
to invoke gigantic debacles of water rushing over the land, and to
these he attributed the transport of large boulders and the smoothing
and striation of rocks, now referred to the action of glaciers
and ice-sheets.
2 The most illustrious of Hall's successors, A. Daubree, has made
generous recognition of the importance of the work of the early
master. Daubree's own studies in experimental geology are a monu-
ment of patient, skilful and original research, and well sustain the
high reputation of the French school of geologists.
326 Robert Jameson
might be sent forth to combat the errors of the
dominant Wernerianism. He did what he could in
that direction by preparing and publishing his admir-
able " Illustrations/' which were widely read, and, as
Hall has recorded, exerted a powerful influence on
the minds of the most eminent men of science of
the day.
But another influence, strongly antagonistic to the
progress of the Huttonian philosophy, was established
in Edinburgh at the very time when the prospect
seemed so fair for the creation of a Scottish school
which might do much to further the advance of
sound geology. Robert Jameson (1774-1854), whose
influence and writings have been referred to in Chap-
ter VIII., had studied for nearly two years at
Freiberg under Werner. After two more years spent
in continental travel, full of enthusiasm for his
master's system, he had returned to the Scottish
capital in 1804, when he was elected to the Chair
of Natural History in the University. His genial
personal character, and his zeal for the Freiberg faith
soon gathered a band of ardent followers around
him. He had much of Werner's power of fostering
in others a love of the subjects that interested him-
self. Travelling widely over Scotland, from the
southern borders to the furthest Shetland Isles, he
everywhere saw the rocks through Saxon spectacles.
From the very beginning, the books and papers
which he wrote were drawn up after the most ap-
proved Wernerian method, pervaded by the amplest
confidence in that method, and by hardly disguised
contempt for every other. Nowhere indeed can the
The Wernerian Natural History Society 3 27
peculiarities of the Wernerian style be seen in more
typical perfection than in the writings of the Edin-
burgh professor. 1
In the year 1808, Jameson founded a new scientific
association in Edinburgh, which he called the a Wer-
nerian Natural History Society," with the great
Werner himself at the head of its list of honorary
members. So far as geology was concerned, the
original aim of this institution appears to have been
to spread the doctrines of Freiberg. I know no
more melancholy contrast in geological literature than
is presented when we pass from the glowing pages
of Playfair, or the suggestive papers of Hall, to
the dreary geognostical communications in the first
published Memoirs of this Wernerian Society. On
the one side, we breathe the spirit of the most
enlightened modern geological philosophy, on the
other we grope in the darkness of a Saxon mine,
and listen to the repetition of the familiar shibbo-
leths, which even the more illustrious of Werner's
disciples were elsewhere beginning to discard.
The importation of the Freiberg doctrines into Scot-
land by an actual pupil of Werner, carried with it the
controversy as to the origin of basalt. This question,
it might have been thought, had been practically
settled there by the writings of Hutton, Playfair, and
Hall, even if it had not been completely solved by
1 See, for instance, the way in which he dismisses the observations
of Faujas de St. Fond on Scottish rocks, and the unhesitating declara-
tion that there is not in all Scotland the vestige of a volcano.
Mineralogy of the Scottish Isles (1800), p. 5. He never loses an oppor-
tunity of a sneer at the " Vulcanists " and " fire-philosophers."
328 Robert Jameson
Desmarest, Von Buch, D'Aubuisson, and others on
the Continent. But the advent of Jameson rekindled
the old fires of controversy. The sections of the rocks
laid open among the hills and ravines around Edin-
burgh, which display such admirable illustrations of
eruptive action, were confidently appealed to alike by
the Plutonists and the Neptunists. Jameson carried
his students to Salisbury Crags and Arthur Seat, and
there demonstrated to them that the so-called igneous
rocks were manifestly merely chemical precipitates in
the " Independent Coal formation." The Huttonians
were ready to conduct any interested stranger to the
very same sections to prove that the whinstone was
an igneous intrusion. There is a characteristic anec-
dote told of one of these excursions in an article
by Dr. W. H. Fitton in the Edinburgh Review. One
of the Irish upholders of the aqueous origin of basalt,
Dr. Richardson, had attained some notoriety from
having found fossils in what he called basalt at Port-
rush, on the coast of Antrim. His discovery was
eagerly quoted by those who maintained the aqueous
origin of that rock, and though eventually Playfair
showed that the fossils really lie in Lias shale, which
has been baked into a flinty condition by an intrusive
basaltic sheet, this explanation was not accepted by the
other side, and the fossiliferous basalt of Antrim con-
tinued to be cited as an indubitable fact by the zealous
partizans of Werner. While these were still matters
of controversy Dr. Richardson paid a visit to Scot-
land, chiefly with reference to fiorin grass, in which he
was interested. The writer in the Edinburgh Review
tells us that he was asked by Sir James Hall, to meet
Irish opponents of Hut ton 329
Dr. Hope and the Irish geologist. " It was arranged
that the party should go to Salisbury Crags, to show
Dr. Richardson a junction of the sandstone with the
trap, which was regarded as an instructive example
of that class of facts. After reaching the spot, Sir
James pointed out the great disturbance that had taken
place at the junction, and particularly called the atten-
tion of the doctor to a piece of sandstone which had
been whirled up during the convulsion and enclosed
in the trap. When Sir James had finished his lecture,
the doctor did not attempt to explain the facts before
him on any principle of his own, nor did he recur
to the shallow evasion of regarding the enclosed sand-
stone as contemporaneous with the trap ; but he burst
out into the strongest expressions of contemptuous
surprise that a theory of the earth should be founded
on such small and trivial appearances ! He had been
accustomed, he said, to look at Nature in her grandest
aspects, and to trace her hand in the gigantic cliffs
of the Irish coast ; and he could not conceive how
opinions thus formed could be shaken by such minute
irregularities as those which had been shown to him.
The two Huttonian philosophers were confounded ;
and, if we recollect rightly, the weight of an acre of
fiorin and the number of bullocks it would feed formed
the remaining subjects of conversation." 1
It is not needful to follow into further detail the
history of the opposition encountered by the Huttonian
theory of the earth. Some of the bitterest antagonists
of Hutton hailed from Ireland. Besides Richardson,
with his fossiliferous basalt, there was Kirwan, President
1 Edinburgh Review, No. Ixv. 1837, p. 9.
33 Decay of IVernerianism at Edinburgh
of the Royal Irish Academy, whose ungenerous attacks
stung Hutton into the preparation of his larger treatise.
In England and on the Continent another determined
opponent was found in the versatile and prolific De
Luc. But though these men wielded great influence
in their day, their writings have fallen into deserved
oblivion. They are never read save by the curious
student, who has leisure and inclination to dig among
the cemeteries of geological literature.
The gradual progress of the Huttonian school and
the concomitant decay of Wernerianism at Edinburgh,
are well indicated by the eight volumes of Memoirs
published by Jameson's Wernerian Society, which
ranged from 1811 to 1839, an interval of less than a
generation. The early numbers might have emanated
from Freiberg itself. Not a sentiment is to be found
in them of which Werner himself would not have
approved. How heartily, for example, Jameson must
have welcomed the concluding sentence of a paper
by one of the ablest of his associates when, after a not
very complimentary allusion to Hutton's views about
central heat, the remark is made u He who has the
boldness to build a theory of the earth without a know-
ledge of the natural history of rocks, will daily meet
with facts to puzzle and mortify him." 1 The fate
which this complacent Wernerian here predicted for
the followers of Hutton, was now surely and steadily
overtaking his own brethren. One by one the faithful
began to fail, and, as we have seen, those who had
gone out to preach the faith of Freiberg came back
!The Rev. John Fleming, Mem. Wer. Soc. vol. ii. (1813),
p. 154.
Defection of Jameson's Pupils 331
convinced of its errors, and of the truth of much which
they had held up to scorn in the tenets of the Plu-
tonists. Even among Jameson's own students, as
already noticed (ante, pp. 241, 263), defections began to
appear in the early decades of last century. His friends
might translate into English, and publish at Edinburgh,
tracts of the most orthodox Wernerianism, such as
Werner's Treatise on Veins , or Von Buch's Description
of Landeck, or D' Aubuisson's Basalts of Saxony. But his
pupils, who went farther afield, who came into contact
with the distinct current of opposition to some of the
doctrines of the Freiberg school that was now setting
in on the Continent, who began seriously to study the
igneous rocks of the earth's crust, and who found at
every turn facts that could not be fitted into the system
of Freiberg, gradually, though often very reluctantly,
went over to the opposite camp. Men like Ami Boue
would send to Jameson notes of their travels, full of
what a staunch Wernerian could not but regard as the
rankest heresy. 1 But the Professor with great impar-
tiality printed these in the Society's publications. And
so by degrees the Memoirs of the Wernerian Society
ceased to bear any trace of Wernerianism, and con-
tained papers of which any Huttonian might have been
proud to be the author. 2
One important result of the keen controversies
1 See Mem. Wer. Soc. vol. iv. (1822), p. 91.
2 See, for example, the papers by Hay Cunningham in vols. vii.
and viii. In an Address to the Geological Society in 1828 Fitton
alluded to the universal adoption in Britain of " a modified volcanic
theory, and the complete subsidence, or almost oblivion of the
Wernerian and Neptunian hypotheses." Proc. Geol. Soc. i. p. 55.
33 2 Decay of mere Theorizing
between the Vulcanist and Neptunist schools in Europe
is to be found in the appeal that was necessitated to
Nature herself for a solution of the disputed problems.
The days of mere theorizing in the cabinet or the
study had now passed away. Everywhere there was
aroused a spirit of inquiry into the evidence furnished
by the earth itself as to its history. The main theo-
retical principles of the science had been established, so
far as related to geological processes and their influence
in the structure of the terrestrial crust. But the
palaeontological side of geology had still to be opened
up. The fruitful doctrine of stratigraphy remained
to be developed and applied to the elucidation of the
grand record of geological history. How this doctrine,
which has done more than any other for the progress
of geological investigation, was worked out will be the
subject of the next four chapters.
CHAPTER XI
THE Rise of Stratigraphical Geology and of Palaeontology Giraud-
Soulavie, Lamarck, Cuvier, Brongniart, and Omalius d'Halloy
in France.
THAT the rocks around and beneath us contain the
record of terrestrial revolutions before the establish-
ment of the present dry land, was an idea clearly
present to the minds of the early Italian geologists,
and, having been so eloquently enforced by Buffon,
was generally admitted, before the end of the
eighteenth century, by all who interested themselves
in minerals and rocks. The Neptunists and Vulcan-
ists might dispute vigorously over their respective
creeds, but they all agreed in maintaining the doctrine
of a geological succession. Werner made this doctrine
a cardinal part of his system, and brought it into
greater prominence than it had ever held before his
time. His sequence of formations from granite, at
the base, to the youngest river-gravel or sea-formed
silt, betokened, in his view, a gradual development of
deposits, which began with the chemical precipitates
of a universal ocean, and ended with the modern
mechanical and other accumulations of terrestrial sur-
faces, as well as of the sea-floor. But, as we have
334 The Doctrine of Geological Succession
seen, the lithological characters on which he based
the discrimination of his various formations proved
to be unreliable. Granite was soon found not always
to lie at the bottom. Basalt, at first placed by him
among the oldest formations, turned up incontinently
among the youngest. He and his disciples were
consequently obliged to alter and patch the Freiberg
system, till it lost its simplicity and self-consistence,
and was still as far as ever from corresponding with
the complex order which nature had followed. Ob-
viously the Wernerian school had not found the key
to the problem, though it had done service in
showing how far a lithological sequence could be
traced among the oldest rocks.
Hutton's views on this question were in some
respects even less advanced than Werner's. He
realized, as no one had ever done so clearly before
him, the evidence for the universal decay of the land.
At the same time, he perceived that unless some
compensating agency came into play, the whole of
the dry land must eventually be washed into the sea.
The upturned condition of the Primary strata, which
had once been formed under the sea, furnished him
with proofs that in past time the sea-floor has been
upheaved into land. Without invoking any fanciful
theory, he planted his feet firmly on these two classes
of facts, which could be fully demonstrated. To his
mind the earth revealed no trace of a beginning, no
prospect of an end. All that he could see was the
evidence of a succession of degradations and up-
heavals, by which the balance of sea and land and
the habitable condition of our globe were perpetuated.
Recognition of the importance of Fossils 335
Hutton was unable to say how many of these revo-
lutions may be chronicled among the rocks of the
earth's crust 1 Nor did he discover any method by
which their general sequence over the whole globe
could be determined.
A totally new pathway of investigation had now to
be opened up. The part that had hitherto been
played by species of minerals and rocks was hence-
forth to be taken by species of plants and animals.
Organic remains, imbedded in the strata of the earth's
crust, had been abundantly appealed to as evidence
of the former presence of the sea upon the land,
or as proofs of upheaval of the sea-floor. But they
were now to receive far closer attention, until they
were found to contain the key to geological history,
to furnish a basis by which the past revolutions of
the globe could be chronologically arranged and
accurately described, and to cast a flood of light
upon the history and development of organised life
upon the surface of the earth.
Apart altogether from questions of cosmogony or
of geological theory, some of the broad facts of
stratigraphy could not but, at an early time, attract
attention. In regions of little-disturbed sedimentary
rocks, the superposition of distinct strata, one upon
another, was too obvious to escape notice. A little
travel with observant eyes would enable men to see
that the same kinds of strata, accompanied by the
1 Playfair thought that the revolutions may have been often
repeated, and that our present continents appear to be the third
in succession, of which relics may be observed among the rocks.
Works, vol. iv. p. 55.
336 Lister's observations on Fossils
same topographical characters, ranged from district
to district, across wide regions. We have found that
it was in countries of regular and gently-inclined
stratified rocks that Lehmann and Fttchsel made their
observations, which paved the way for the develop-
ment of the idea of palaeontological succession. We
have now to trace the growth of this idea, and the
discovery that organic remains furnish the clue to the
relative chronology of the strata in which they are
imbedded.
The fact that different rocks contain dissimilar but
distinctive fossils had been noted by various observers
long before its geological significance was perceived.
Thus, as far back as 1671, we find Martin Lister
affirming, in a letter already cited (p. 76), that "quarries
of different stone yield us quite different sorts or species
of shells not only one from another (as those Cockle-
stones of the iron-stone quarries of Adderton, in
Yorkshire, differ from those found in the lead-mines
of the neighbouring mountains, and both these from
the cockle-quarrie of Wansford Bridge, in North-
amptonshire ; and all three from those to be found
in the quarries about Gunthrop and Beauvour Castle,
etc.), but, I dare boldly say, from anything in nature
besides, that either the land, salt or freshwater doth
yield us." 1
Again, John Strange writing in 1779 remarks that
1 Phil. Trans, vol. vi. p. 2283. Greenough in his Critical Ex-
amination of the First Principles of Geology, 1819, (p. 284), in quoting
this passage, adds that Lister had " followed the course of the Chalk
Marl over an extensive tract of country by mere attention to its
fossils," but no reference is given to the authority for this statement.
Strangers tracing of Lias Outcrop 337
" the Gryphites oyster is not only found abundantly in
the lower part of Monmouthshire and about Purton
Passage, but also extends in considerable aggregates
along the neighbouring midland counties ; having
myself traced them, either in gravel or limestone,
through Gloucestershire, Worcestershire, Warwick-
shire and Leicestershire, occupying in like manner
the lower parts of those counties, under the hills." 1
It would thus appear that the outcrop of the Lias
had been traced, by means of its fossils, across a
great part of England some years before William
Smith began his labours.
There were two regions of Europe well fitted to
furnish any competent inquirers with the evidence for
establishing, by means of fossil organic remains, this
supremely important section of modern geology. In
France, the Secondary and Tertiary formations lie in
undisturbed succession, one above another, over
hundreds of square miles. They come to the surface,
not obscured under superficial deposits, but projecting
their escarpments to the day, and showing, by their
topographical contours, the sharply defined limits of
their several groups. Again, in England, the same
formations cover the southern and eastern parts of
the country, displaying everywhere the same clear
evidence of their arrangement. Let us trace the
progress of discovery in each of these regions. To a
large extent this progress was simultaneous, but there
is no evidence that the earlier workers in the one
country were aware of what was being done in the
other.
1 Archaeokgidj vol. vi. (1782), p. 36.
Y
338 Giraud-Soulame
To the Abbe J. L. Giraud-Soulavie (1752-1813)
the merit must be assigned of having planted the first
seeds from which the magnificent growth of strati-
graphical geology in France has sprung. Among
other works, he wrote a Natural History of Southern
France in seven volumes, of which the first two
appeared in the year 1780. He gave much of his
attention to the old volcanoes of his native country,
and devoted several of his volumes entirely to their
description. But his chief claim to notice here lies
in a particular chapter of his work which, he tells us,
was read before the Royal Academy of Sciences of
Paris on I4th August I779- 1 In describing the cal-
careous mountains of the Vivarais, he divided the
limestones into five epochs or ages, the strata in each
of which are marked by a distinct assemblage of
fossil shells. The first of these ages, he declared,
was represented by limestone containing organic
remains with no living analogues, such as ammonites,
belemnites, terebratulae, gryphites, etc. Having no
more ancient strata in the district, the Abbe called
this oldest limestone primordial. His second age
was indicated by limestone, in which the fossils of
the preceding epoch were still found, but associated
with some others now living in our seas. Among the
new forms of life that appeared in these secondary
strata he enumerated chamas, mussels, comb-shells,
nautili, etc. These, he said, inhabited the sea, to-
gether with survivors from the first age, but the
latter at the end of the second age disappeared.
1 Histoire Naturelle de la France Meridionale, tome i. 2 me partie,
chap. viii. p. 317.
His "Five Ages" in the Vivarais 339
Above their remains other races established them-
selves, and carried on the succession of organised
beings.
The third age was one in which the shells were of
recent forms, with descendants that inhabit the present
seas. The remains of these shells were found in a
soft white limestone, but not a trace of ammonite,
belemnite, or gryphite was to be seen associated with
them. Among the organisms named by the Abb
were limpets, whelks, volutes, oysters, sea-urchins,
and others, the number of species increasing with the
comparative recentness of the formation. He thought,
like Werner, that the most ancient deposits had been
accumulated at the highest levels, when the sea covered
the whole region, and that, as the waters sank,
successively younger formations were laid down at
lower and lower levels.
From the occurrence of worn pebbles of basalt in
the third limestone, Giraud-Soulavie inferred that vol-
canic eruptions had preceded that formation, and that
an enormous duration of time was indicated by the
erosion of the lavas of these volcanoes, and the
transport and deposit of their detritus in the white
limestone.
The fourth age in the Vivarais was represented by
certain carbonaceous shales or slates, containing the
remains of primordial vegetation to which it was
difficult to discover the modern analogues. Giraud-
Soulavie believed that he could observe among these
slates a succession of organic remains similar to that
displayed by the limestones, those strata which lay on
the oldest marble containing ammonites, while the
34 Giraud-Soulavie
most recent enclosed, but only rarely, unknown plants
mingled with known forms. It would thus appear
that the deposits of the so-called fourth age were
more or less equivalents of those of the three cal-
careous ages.
The fifth age was characterised by deposits of
conglomerate and modern alluvium, containing fossil
trees, together with bones and teeth of elephants and
other animals. " Such is the general picture," the
Abbe remarks, " presented by our old hills of the
Vivarais, and of the modern plains around them.
The progress of time and, above all, of increased
observation will augment the number of epochs which
I have given, and fill up the blanks ; but they will
not change the relative places which 1 have assigned to
these epochs." * He felt confident that if the facts
observed by him in the Vivarais were confirmed in
other regions, a historical chronology of fossil and
living organisms would be established on a basis of
incontestible truth. In his last volume, replying to
some objections made to his opinions regarding the
succession of animals in time, he contends that the
difference between the fossils of different countries is
due not to a geographical but to a chronological cause.
" The sea," he says, " produces no more ammonites,
because these shells belong to older periods or other
climates. The difference between the shells in the
rocks rests on the difference in their relative antiquity,
and not on mere local causes. If an earthquake were
to submerge the ammonite -bearing rocks of the
Vivarais beneath the Mediterranean, the sea returning
1 Op. dt. p. 350.
Sagacity of his generalisations 341
to its old site would not bring back its old shells.
The course of time has destroyed the species, and
they are no longer to be found in the more recent
rocks." i
The sagacity of these views will at once be acknow-
ledged. Yet they seem to have made, for a time,
no way either in France or elsewhere. The worthy
Abbe, though a good observer and a logical reasoner,
was a singularly bad writer. At the end of the
eighteenth century a wretched style was an unpardon-
able offence even in a man of science. 2 Whatever
may have been the cause, Giraud-Soulavie has fallen
into the background. His fame has been eclipsed,
even in France, by the more brilliant work of his
successors. Yet, in any general survey of geological
progress, it is only just to acknowledge how firmly
he had grasped some of the fundamental truths of
stratigraphical geology, at a time when the barren
controversy about the origin of basalt was the main
topic of geological discussion throughout Europe.
We have seen that the distinctness, regularity, and
persistence of the outcrops of the various geological
formations of the Paris basin suggested to Guettard
the first idea of depicting on maps the geographical
distribution of rocks and minerals. The same region
and the same features of topography and structure
inspired long afterwards a series of researches that
contributed in large measure to the establishment of
the principles of geological stratigraphy. No fitter
birthplace could be found in Europe for the rise of
1 Op. cit. tome vii. (1784), p. 157.
2 D'Archiac, Geologic et Pa/eon fotogie, 1866, p. 145.
34 2 G. P. Rouelle
this great department of science. Around the capital
of France, the Tertiary and Secondary formations are
ranged in orderly sequence, group emerging from
under group, to the far confines of Brittany on the
west, the hills of the Ardennes and the Vosges on
the east, and the central plateau on the south. Not
only is the succession of the strata clear, but their
abundant fossils furnish a most complete basis for
stratigraphical arrangement and comparison.
Various observers had been struck with the orderly
sequence of rocks in this classic region. Desmarest
tells us that the chemist G. F. Rouelle (1703-1770)
was so impressed with its symmetry of structure that,
though he never wrote anything on the subject, he
used to discourse on it to his students at the Jardin
des Plantes, of whom Desmarest himself appears to
have been one. He would enlarge to them upon the
significance of the masses of shells imbedded in the
rocks of the earth's surface, pointing out that these
rocks were not disposed at random, as had been
supposed. He saw that the shells were not the
same in all regions, that certain forms were always
found associated together, while others were never
to be met with in the same strata or layers. He
noticed, as Guettard had done before him, that in
some districts the fossil shells were grouped in exactly
the same kind of arrangement and distribution as on
the floor of the present sea a fact which, in his
eyes, disproved the notion that these marine organisms
had been brought together by some violent deluge ;
but which, on the other hand, showed that the present
land had once been the bottom of the sea, and had been
Researches in the Paris Basin 343
laid dry by some revolution that took place without
producing any disturbance of the strata. Rouelle
recognised a constant order in the arrangement of the
shells. Thus, immediately around Paris, he found
certain strata to be full of screw shells (Turritella,
Cerithium, etc.), and to extend to Chaumont, on the
one side, and to Courtagnon near Rheims, on the other.
He pointed to a second deposit, or u mass " as he
called it, full of belemnites, ammonites, gryphites,
etc. (Jurassic), forming a long and broad band out-
side the eastern border of the Chalk, and stretching
north and south beyond that formation up to the old
rocks of the Morvan. Desmarest's account of his
teacher's opinions was published in the third year of
the Republic. 1 It is thus evident that Rouelle had
formed remarkably correct views of the general strati-
graphy of the Paris basin probably long before 1794.
Desmarest himself published many valuable observa-
tions regarding the rocks of the Paris basin in separate
articles in his great Geographic Physique. Lamanon had
written on the gypsum deposits of the region, which
he regarded as marking the sites of former lakes,
and from which he described and figured the remains
of mammals, birds and fishes. Noting the alterna-
tions of gypsum and marls, he traced what he
believed to be the limits of the sheets of freshwater
in which they were successively deposited. Still more
precise was the grouping adopted by Lavoisier (1743-
1794). This great man, who, if he had not given
himself up to chemistry, might have become one of
^Geographic Physique (Encyclopedic Methodiqui)^ tome i. (1794),
pp. 409-431.
344 Lavoisier as Geologist
the most illustrious among the founders of geology,
was, as already stated (p. 1 1 5), associated early in life
with Guettard in the construction of mineralogical
maps of France. As far back as the year 1789, he
distinguished between what he called littoral banks and
pelagic banks, which were formed at different distances
from the land, and were marked by distinct kinds
of sediment and peculiar organisms. He thought
that the different strata, in such a basin as that of
the Seine, pointed to very slow oscillations of the
level of the sea, and he believed that a section of
all the stratified deposits between the coasts and the
mountains would furnish an alternation of littoral
and pelagic banks, and would reveal by the number
of strata the number of excursions made by the waters
of the ocean. Lavoisier accompanied his essay with
sections which gave the first outline of a correct
classification of the Tertiary deposits of the Paris
region. His sketch was imperfect, but it represented
in their true sequence the white Chalk supporting
the Plastic Clay, lower sands, Calcaire Grossier, upper
sands and upper lacustrine limestone. 1
A few years later, a more perfect classification of
these Tertiary deposits was published by Coupe, but
without sufficiently detailed observations to convince
his contemporaries that the work was wholly reliable. 2
1 Mem. Acad. Roy. Sciences (1789), p. 350, pi. 7. This memoir
of Lavoisier on modern horizontal strata and their disposition
is fully noticed by Desmarest in the first volume of his Geographic
Physique, p. 783. Lavoisier's distinction between pelagic and
littoral organisms and deposits was afterwards adopted by Lamarck
(postea, p. 355).
2 Journ. de Physique, tome lix. (1804), pp. 161-176.
Lamarck's Biography 345
The Tertiary formations of the great basin of
the Seine were destined not only to furnish a vast
impetus to the development of stratigraphical geology,
but to provide the first broad scientific basis for the
foundation of the science of Palaeontology. In this
momentous development of geological science two
names stand out with conspicuous prominence among
those who carried on the work Lamarck and Cuvier.
Jean-Baptiste-Pierre-Antoine de Monet, Chevalier
de Lamarck (1744-1829) came of an ancient but
somewhat decayed family, and was born in a village
of Picardy, as the eleventh and youngest child of
the Seigneur de Beam. 1 The ancestral patrimony
having become too slender to provide a living for
the boy, he was designed for the church, and was
sent to begin his studies under the Jesuits of Amiens.
But since for centuries his ancestors had been soldiers,
and he had three brothers in the army, he could not
bring himself to settle down finally to the peaceful
life of an ecclesiastic. The death of his father in
1760 gave him an opportunity of leaving his books
and joining the French forces that were then engaged
in the disastrous war which began in 1756. With no
other passport than a letter of introduction from a
lady in his neighbourhood to the Colonel of the
Beaujolais regiment, he set out for the seat of war,
mounted on a sorry nag, and attended by a poor
1 For the biographical details of Lamarck's life I am indebted
to Cuvier's Eloge of him in the Recueil des Eloges Historiques,
vol. iii. p. 179, and to the excellent volume by Mr. A. S.
Packard, Lamarck, the Founder of Evolution: His Life and Work,
1901.
346 Lamarck
lad of his village. He arrived at the camp immedi-
ately before an attack was to be made on the allied
army under Prince Ferdinand of Brunswick.
In this attack, known as the battle of Willingshausen
(i4th July 1761), which ended in the signal defeat
of the French, young Lamarck at last found himself
in charge of his company, whereof all the officers had
been killed in the action, and which was left behind
unnoticed in the confusion of the retreat. The oldest
grenadier of the band counselled him to retire, but
the youthful volunteer, with characteristic courage,
refused to move without orders from the post that
had been assigned to them. Not without some risk
and difficulty he and the remnant of his company
were at last relieved and withdrawn. He was at
once rewarded for his valour by being made an
officer by the Commander-in-Chief. Further pro-
motion followed, and after the peace he passed some
time in garrison duty. The enforced leisure of this
kind of life, and the seclusion rendered necessary by
a severe accident, led him to return to some of the
studies, more particularly to botany, which had inter-
ested him during his stay at the College.
Seeing at last no prospect of a satisfactory future
in the army he resolved to try his fortune elsewhere,
and to qualify himself for the medical profession.
Having, however, an annual allowance of no more
than 400 francs, he eked out his slender income by
working for a portion of his time in the office of a
banker. His medical education is said to have
extended over four years. But he does not seem
ever to have taken up the practice of the profession,
His first scientific Paper 347
though the scientific training he then received must
have been an excellent prelude to his subsequent
career.
Lamarck, from his early love for plants, threw
himself with all the ardour of his enthusiastic and
indomitable nature into the study of botany, inso-
much that at the age of 24 he abandoned everything
else to be able to devote himself to its pursuit. He
worked under Bernard de Jussieu at the Jardin des
Plantes, and made botanical excursions round Paris
with Rousseau. He was eventually appointed Keeper
of the Herbarium of the Royal Gardens at the miser-
able salary of 1000 francs, afterwards increased to
1800. Yet his first published essay showed that he
was not entirely engrossed in botanical studies. Not
improbably the high garret in the Quartier Latin,
which he had tenanted as a student, and which com-
manded a wide view of the sky, had given him
occasion to watch the movements of the clouds and
other phenomena of meteorology. At all events,
in the year 1776, when he was 32 years of age, he
presented to the Academy of Sciences a memoir
" On the Vapours of the Atmosphere," which was well
received, and proved to be the first of a long series of
contributions from him to meteorological science.
After ten years of earnest botanical study Lamarck
published in 1778 his Flore Franfaise in three volumes.
In this work he gave a succinct description of all
the wild plants of the country, arranged in accord-
ance, not with the Linnaean system of nomenclature,
but with a classification which he had himself devised.
This treatise, at the special instance of BufFon, was
348 Lamarck
printed at the expense of the Government and it
at once placed its author in a prominent position
among the naturalists of the day. Buffon's friend-
ship proved a valuable aid to him in various ways,
and doubtless helped to secure his speedy election
into the Academy of Sciences. But he still remained
exceedingly poor, and had a hard struggle to support
himself and the family that was now growing up
around him.
From the time of the appearance of the F/ore
Franc, aise Lamarck continued for fifteen years to work
mainly at botanical subjects, contributing papers to the
Memoirs of the Academy of Sciences, and producing
the successive botanical volumes in the great Encyclopedic
Methodique. These labours had raised him into the
front rank of botanists, but they did not make the
tenure of his appointment so secure that he had not
to defend his position. He was compelled to publish
a statement of the nature and importance of the duties
he had to perform, and at the same time he urged that
more ample provision should be made for the scientific
work of the Museum and Garden. The National
Convention took up the matter, and in the summer
of 1793 reorganised and enlarged the establishment.
Of the twelve new chairs then founded, the botanical
appointments were naturally bestowed on the two senior
distinguished botanists of the staff, Jussieu and Des-
fontaines, while Lamarck was offered one of the chairs
of zoology. When it is remembered that he was now
verging on 50 years of age, and that he had never
paid much attention to zoological matters, but had
given up his time and energies to botany, one may
Professor of Invertebrate Zoology 349
well feel astonishment at the courage of the man in
accepting the appointment and resolving to make him-
self master of another science. The title of his chair
was " Professor of Zoology ; of insects, of worms and
of microscopic animals," and the annual stipend 2868
livres or about 115 sterling. Having made up his
mind to undertake the new duties, he threw himself
with such courage and zeal into them, that before many
years he was acclaimed as an even more accomplished
and original zoologist than he had been a botanist.
Yet he continued to find time for excursions into
physical science. He went on for a succession of years
publishing meteorological reports, which may be re-
garded as in some respects forerunners of the weather-
charts of recent times. He also entered the lists
against the prevalent chemical and physical opinions
of the day, propounding some extraordinary views
which had no experimental basis and were generally
regarded as too eccentric to require refutation.
In the course of his zoological studies Lamarck was
led directly and indirectly to make important contribu-
tions towards the advance of geology. In dealing with
the invertebrata, especially with the mollusca, he studied
and described the varied assemblage of fossil shells so
abundantly and perfectly preserved among the Tertiary
deposits of the Paris basin. Correlating the living with
the extinct forms, he was enabled to present a far
broader and more accurate picture of the invertebrate
division of the animal kingdom than had ever before
been attempted. Cuvier has been claimed as the great
founder of vertebrate Palaeontology; Lamarck may
with at least equal justice be regarded as the founder
35 Lamarck
of the invertebrate half of the science. His researches
among the shells of the Paris basin furnished, as we
shall see, an accurately determined basis on which
Cuvier and Brongniart could work out the stratigraphy
of that region.
But Lamarck's original and philosophical genius
could not be confined within the limits of the mere
determination of new genera and species. From the
contemplation of these details, he advanced into broad
generalisations among the higher problems of biology.
He propounded views in organic evolution which,
though received at the time with ridicule and subse-
quently with neglect, have in later years been revived,
and meet now with a constantly increasing degree of
acceptance. His Philosophic Zoologique has become a
classic in biological literature, while his great work the
Animaux Sans Vertebres, which appeared in seven vol-
umes between 1815 and 1822, marks a memorable
epoch in the march of natural history, and will ever
remain one of the glories of French science.
Though Lamarck wrote little on geology, the extent
to which he had pondered over the problems of the
science, which in his time had hardly taken definite
shape, is well illustrated by the little volume which he
published in 1802 under the title of Hydrogeologiel
x The full title of this little known but extremely interesting
treatise is as follows : " Hydrogologie, ou Recherches sur 1'influence
qu'ont les eaux sur la surface du globe terrestre ; sur les causes de
1'existence du bassin des mers, de son deplacement et de son transport
successif sur les diffe~rentes points de la surface de ce globe ; enfin
sur les changemens que les corps vivans exercent sur la nature et
Tetat de cette surface. Par J. B. Lamarck, Membre de 1'Institut
National de France, Professeur-Administrateur au Museum d'Histoire
On origin of Hills and Valleys 351
The object of this work was to propose and attempt
to solve four problems, the solution of which must
constitute the foundation of any true theory of the
earth, ist. What are the natural effects of the move-
ments of the terrestrial waters on the surface of the
globe ? 2nd. Why is the sea confined to a basin and
within limits that always separate it from the projecting
dry land ? 3rd. Has the basin of the sea always
existed as we now see it, and if not, what is the cause
that led to its being elsewhere, and why is it not there
still ? 4th. What is the influence of living organisms
on the mineral substances of the earth's surface and
crust, and what are the general results of this influence ?
i. Lamarck realised more clearly than most of his
contemporaries, the part played by terrestrial waters
on the surface of the land. He recognised that
nothing can ultimately resist the alternating influence
of wetness and drought, combined with that of heat
and cold, and that the disintegration of mineral sub-
stances by these atmospheric conditions prepares the
way for the erosive action of running water in all its
various forms. As the result of this action, plains
are hollowed out into ravines, and these are widened
into valleys. The spaces between rivers are worn into
ridges, which in course of time become high crests.
Naturelle &c." Paris, An X (1802). It is interesting to note that
this volume and Playfair's Illustrations of the Huttonian Theory were
published in the same year, and to contrast the opinions of the two
writers. In all that relates to the organic world, the French naturalist
had a far wider outlook than the Scottish philosopher, while on the
other hand, the latter showed a truer insight into most of the physical
problems of geology with which he dealt.
35 2 Lamarck
If the surface of the land had been at first a vast
plain, yet at the end of a certain time, through the
operation of its water-courses, it would have lost that
aspect, and would ultimately come to be traversed with
mountains like those with which we are familiar.
In these deductions, the French philosopher re-echoed
the principles established by De Saussure, Desmarest
and Hutton. But he carried them to an extreme
which may possibly have raised a prejudice against
them. He declared that every mountain which has
not been erupted by volcanic action or some other
local catastrophe, has been cut out of a plain, so that
the mountain-summits represent the relics of that
plain, save in so far as its level has been lowered in
the general degradation. Geologists have accepted this
explanation for the systems of mountains which, having
no internal or tectonic structure peculiar to themselves,
appear to have been carved out of ancient tablelands.
Lamarck, however, though he speaks of local catas-
trophes, seems to have had no conception of any wide-
spread cause whereby the terrestrial crust has from
time to time been folded and driven upwards into
vast chains of mountains. He admits that in many
mountains the component strata are often vertical or
highly inclined. But he will not on that account believe
in any universal catastrophe, such as had been demanded
by many previous writers, and was still loudly advocated
in his own time by his fellow-countryman Cuvier. He
considers that the inclination of the strata may be due
partly to the natural slope of the surface on which
the sediments were originally deposited, like the talus-
slopes of mountains, partly and frequently to many
On origin of Ocean-basin 353
kinds of accidents, such as arise from local subsidence.
But he enters into no further detail, and shows no
personal knowledge of the real structure of a true
mountain-chain.
The task of the fresh waters, according to this
thinker, is thus two-fold ; to erode the dry land,
thereby producing valleys and mountains, and to
spread the detritus over plains, before finally sweeping
it out to sea, where it tends towards the filling up of
the sea-basins.
2. In attempting to solve his second problem
Lamarck ventured far beyond his depth in regard to
the physics of the earth, and broached some crude
ideas, based on no reliable evidence, but directly con-
trary to such facts regarding the ocean as were known
in his time. He conceived the ocean-basin to owe
its existence and preservation to the perpetual oscilla-
tion of the tides, and partly also to a general westerly
movement of the water. He supposed the tidal
oscillation to be a gigantic force which has actually
eroded the basin and now prevents it from being
shallowed, through the deposit of land-derived sedi-
ment, by continually scouring this sediment out and
casting it up along the more sheltered shores of the
land. Since the sea does not cover the whole globe, but
is gathered into its vast basin, the centre of gravity of
the earth does not strictly coincide with what Lamarck
called its "centre of form." Owing to the shifting
of the ocean-bed westward, he thought that the centre
of gravity is simultaneously displaced and slowly makes
a revolution round the centre of form. In these
speculations the great naturalist displayed a singular
354 Lamarck
misapprehension of the effects of the tides, and made
no allowance for any movement of the terrestrial crust.
3. The same limited acquaintance with the facts
which were needed for the solution of his difficulties
is not less conspicuous in the way in which he dealt
with his third problem. He thinks that in spite of
the tidal oscillations which seem to retard the deposit
of sediment over the sea-floor, the basin of the ocean
might eventually be filled up, or that at least the sea
would rise above its present mean level, if some
unceasingly active cause did not counteract this ten-
dency. Looking around at the margin of the land
in different quarters of the globe, he sees what seems
to him evidence that the waters of the ocean are
subject to a continual impulse which drives them
from east to west, due, he believed, to the influence
chiefly of the moon, but partly also of the sun. He
does not show, however, in what form this impulse is
imparted otherwise than in the tidal wave. The
eastern coasts of the continents appear in his eyes to
be wasted by the attacks of the sea, while the western
shores, being sheltered from these attacks, receive
deposits of sediment. He looks on the Gulf of
Mexico as a vast hollow, dug out of the land by the
westerly advance of the Atlantic. The eastern side
of Asia, with its chains of islands and the passage
opened for the marine currents between these islands
and Australia, appeals to his mind as a striking
example of the truth of his generalisation, while the
eastern side of America is hardly less confirmatory,
although the sea has not yet cut through the Isthmus
of Panama.
On the study of Fossils 355
Much more interesting and satisfactory is Lamarck's
fresh demonstration, from authentic and irrefragable
evidence, of the long accepted truth that the sea has
once covered many parts of the surface of the globe
from which it has long disappeared. This evidence
rests on the occurrence of organic remains, and in
dealing with it he evidently feels himself at home with
his subject, and launches warmly into its discussion.
The term "fossil," as we have seen (p. 215), had
been indiscriminately applied to any mineral substance
dug out of the earth, but Lamarck now for the first
time definitely restricts it to the u still recognisable
remains of organised bodies." x After citing a number
of examples of the occurrence of such remains in the
heart of mountains, at great heights above the sea
and in different widely separated parts of the globe,
he proceeds to dwell on the importance of fossils as
monuments that furnish one of the chief means of
ascertaining the revolutions which our globe has
undergone. He urges naturalists to study fossil
shells, to compare them with their analogues in our
present seas, to investigate carefully where each species
is found, the banks formed of them, the different layers
which these banks may display, and other associated
features. He points out, as Lavoisier had done before
him (p. 344), that among fossil shells some are pelagic
and some littoral, and that they even occasionally in-
clude terrestrial and fluviatile forms. These last would,
in his opinion, be much more numerous had not their
greater fragility led to their being generally broken and
destroyed before they could be washed into the sea.
1 Hydrogeologie, p. 55.
356 Lamarck
Discussing the cause of the former long-continued
sojourn of the sea on so many parts of the surface
of the land, he inquires whether we are to invoke
the occurrence of the Deluge or some great catas-
trophes, as had so often been done in the past, and
as continued to be done for many years afterwards
by Cuvier. He will admit such an extraordinary
cause if it be granted to have endured for the vast
periods of time which the accumulation of thick and
regular deposits of marine remains must have required.
But he would rather seek for some explanation that
will be more in accordance with the observed order
of Nature. He was thus a follower of the Huttonian
theory.
And here the great naturalist breaks forth in a
tone that reminds one of the language of his Greek
prototype, Aristotle : " In this globe which we in-
habit, everything is subject to continual and inevitable
changes. These arise from the essential order of
things, and are effected with more or less rapidity or
slowness, according to the varying nature or position
of the objects implicated in them. Nevertheless they
are accomplished within a certain period of time.
For Nature, time is nothing, and is never a diffi-
culty ; she always has it at her disposal, and it is for
her a means without bounds, wherewith she accom-
plishes the greatest as well as the least of her tasks."
" Oh, how vast is the antiquity of our earth ! and
how small are the ideas of those who assign to the
existence of this globe a duration of six thousand
and some hundreds of years from its beginning to
our own days ! " " Losing trace of what has once
On oceanic displacement 357
existed, we can hardly believe nor even conceive the
immensity of our planet's age. Yet how much vaster
still will this antiquity appear to man when he shall
have been able to form a just conception of the
origin of living creatures, as well as of the causes of
their gradual development and improvement, and
above all when he shall perceive that time and the
requisite conditions having been necessary to bring
into existence all the living species now actually to be
seen, he himself is the final result and actual climax
of this development of which the ultimate limit, if
such there be, can never be known." 1
With such a limitless vista of past time to
contemplate, Lamarck could indulge in unfettered
speculation on the secular displacement of the ocean
basin, and the concomitant submergence of the land.
Inappreciably slow though the mutation might be, he
believed it to be part of the regular order of nature,
proceeding without interruption until every part of
the dry land had in succession become the bed of
the sea. In this slow westerly movement, the ocean
seemed to him to have travelled round the globe,
not once but perhaps many times, every part of the
land becoming first the shore, and then passing under
the scour of the great oceanic waters until at last
reduced to form the bottom of the marine abysses.
He thought that this displacement of the basin of
the sea, by producing a constantly variable inequality
in the terrestrial radii, causes a shifting of the centre
of gravity of the globe as well as of the two poles,
and that as this variation, markedly irregular though
1 O/>. dt. pp. 67, 88, 89.
358 Lamarck
it be, appears not to be confined within definite
limits, probably every point on the surface of our
planet may have successively passed through all the
different terrestrial climates. 1
Though his theory of the interchange of land and
sea cannot be accepted, it is impossible to read with-
out admiration Lamarck's marshalling of the facts on
which he relied, and his acute reflections on the deduc-
tions to be drawn from the characters and probable
habitats of organic remains. He points out the im-
portance of distinguishing pelagic from littoral shells,
each series being usually found in distinct beds, the
one marking deep water the other former shore-lines.
Every part of the earth's surface that has once been
overspread by the sea has had twice a zone of
littoral shells and once a deposit of pelagic shells,
making three distinct and successive formations,
representing the passage of a vast lapse of time.
No sudden catastrophe is admissible as an explanation
of the facts ; such an event would have jumbled the
organisms together and would have broken the more
delicate shells, which have nevertheless been admirably
preserved in great numbers among the other fossils.
Again, the bivalves, with which many of the lime-
stones are crowded, would not so commonly have
retained their valves in contact, unless they had lived
and died where their remains are found. In
Lamarck's opinion a large part of the calcareous
material, now to be found on the surface and within
the crust of the earth, has been derived from once
living organisms. He will not admit the propriety
1 Op. cit. p. 87.
On origin of Limestone 359
of the term <c primitive," applied by mineralogists to
the more ancient limestones. Though all trace of
organic structure may have disappeared from these
strata, he nevertheless believes them to have had an
organic origin, and he can indicate the process by
which the organic structures might be destroyed.
He even goes so far as to affirm that such cal-
careous matter did not exist in the primitive earth,
but like other animal and vegetable substances, only
came into existence when it was secreted by living
organisms.
4. To the treatment of the fourth problem Lamarck
devotes nearly as much space as to the other three
Uken together, tempted doubtless to this greater
di;cursiveness by the opportunity to re-state and
develop his peculiar views in physics and chemistry,
anc to claim for the subject a far more important
plae in scientific investigation than his contem-
pora*ies seemed disposed to admit. Without entering
here into his controversy, it may be sufficient to note
the more important geological observations and
deducions wherein the author was either wholly
or patly in the right, and where he led the way
in a ine of inquiry wherein much still remains to
be acamplished.
The crust of the earth, conjectured by Lamarck to
be perhps 3 or 4 leagues thick (13 to 17 kilometres
or 8 to loj English miles), was pictured by him to
be, as rgards its outer part, in a continual state of
alteratior; ceaselessly worked over by the various
forms oi water, by the displacements and alternate
passages f the ocean-basin, by the continual deposits
360 Lamarck
of all kinds formed by living organisms on its exposed
portions ; further by the changes, the upheavals, the
accumulations, the subsidences and excavations pro-
duced in its thickness by volcanoes and earthquakes.
Under these manifold influences it must certainly
have undergone, in its condition and in the nature
of its parts, variations which but for these different
causes could never have taken place. All composite
bodies tend to decay into their component constituents.
Yet the visible crust of the earth consists almost
entirely of compound materials. How is this fact
to be accounted for ? There must be, he thought
some other potent force in Nature which acts antag-
onistically to the tendency towards the resolution tf
combinations into their component constituents, aid
he believed this force to be supplied by living orgin-
isms, or by what he calls the Pouvoir de la 7 ie.
Having long watched the operations of living pants
and animals, he saw that the organic action of Iving
bodies unceasingly forms combinations of substmces,
which, without this action, would never have come
into existence. From this well-founded observation,
however, he leaped to the astounding generalsation
that " the compound mineral substances, whch are
to be found in almost every part of the outc crust
of the globe and form most of its compsition,
while at the same time they are continually modifying
it by the changes they undergo, are all, withoit excep-
tion, the result of the remains and debris <f living
bodies." He had broached this view m>re than
eighteen years earlier and he now complain that so
striking a truth, only discoverable by obervation,
On consolidation of Rocks 361
should have been rejected and apparently scorned
by the very men who ought to have been the first
to welcome it. We can hardly wonder, however,
that his contemporaries should have refrained from
treating this speculation as a serious contribution to
science.
And yet though the conclusion was wholly unten-
able, it must in justice to Lamarck be admitted that
he perceived in this matter, far more vividly than
any other naturalist of his time, the importance of
the part played by plants and animals in effecting
geological changes by decomposing mineral matter,
and thus modifying the surface of the earth and pro-
viding fresh materials for its crust. No one before
his day had been able to follow so clearly the suc-
cessive stages through which organic remains pass until
they become crystalline stone, presenting no trace of
their original organic structure. He distinguished
between the consolidation of stratified rocks through
the deposit of fine sediment (Lapidescence par sedi-
mens\ and through permeation by some cementing
material (Lapidescence par infiltration)^ He showed
that agates and petrifactions are examples of the
results of such infiltration, but he came to the singular
conclusion that the " elementary earth," " vitreous
earth," or silica of the chemists, has been so potent
an agent in infiltration that it constitutes the base
1 In this department of his subject Lamarck held much more
accurate opinions than Hutton and Playfair, who were so carried
away by their view of the efficacy of underground heat, as to
believe that flints and agates had been injected in a molten state
into the rocks in which they are now found.
362 Lamarck
of all the earths and stones of every sort, in short,
of solid matter everywhere.
When he thus threw aside as error all that had
then been ascertained as to the chemistry of minerals,
he found no difficulty in accounting for all rocks as
the results of the decay of organic bodies. He looked
on granite, for example, not as the " primitive " rock
which mineralogists had called it, nor as directly con-
nected with the material that forms the interior of
the globe, but as due to the transport of the decaying
debris of organisms by rivers, and to the accumulation
of this detritus on the floor of the sea. He believed
that all argillaceous materials come from the decay of
plants and all calcareous materials from the remains
of animals, and that from these two chief sources
the most important and abundant earthy and stony
bodies are derived, all the other mineral substances
being only mixtures or modifications of these. Even
metals appeared to him divisible into two series,
according as their earthy base has been supplied by
animals or by plants. Here again he generalised from
the undoubted precipitation of some metallic salts by
organic matter to the production of all metallic sub-
stances from the same cause. His discussion ends
with a pungent attack on the chemists of his day and
their methods, and he declares that though all the
world may believe them, he is content to be alone in
his disbelief.
There can be little doubt that this spirit of opposi-
tion to many of the prevalent opinions of the time,
together with the apparent extravagance of some of
his doctrines, conspired to detract from the position
His services to Geology 363
and influence to which Lamarck's splendid abilities
and achievements justly entitled him among his con-
temporaries. During the last ten years of his long
life he suffered from total blindness, and had to rely
on the affectionate devotion of his eldest daughter for
the completion of such works as he had in progress
before his eyesight failed. The world is becoming
more conscious now of what it owes to the genius
of this illustrious naturalist. Among those students
of science who have most reason to cherish his
memory, geologists should look back gratefully to his
services in starting the science of Palaeontology, in
propounding the doctrine of evolution and in affirm-
ing with great insight some of the fundamental
principles of modern geology.
Returning now to the Paris basin, we may take note
that not until the year 1808 was the Tertiary strati-
graphy of this district worked out in some detail, so as
to furnish a foundation for the establishment of a general
system of stratigraphical geology in France. This task
was accomplished by two men who have left their mark
upon the history of the science, Cuvier and Brongniart.
Georges Chretien Leopold Dagobert Cuvier (1769-
1832) came of an old Protestant family in the Jura,
which in the sixteenth century had fled from persecu-
tion and had settled at Montbeliard, then the chief
town of a little principality belonging to the Duke of
Wilrtemberg. He was born at that place on 23rd
August 1769, and after a singularly brilliant career
at school and at the Caroline Academy of Stuttgart,
became tutor in a Normandy family living near Fecamp.
He had been drawn into the study of natural history,
364 Cumer
when a mere child, by looking over the pages of
Buffon, and had with much ardour taken to the
observation of insects and plants. In Normandy,
the treasures of the sea were opened to him.
Gradually his dissections and descriptions, though
not published, came to the notice of some of the
leading naturalists of France, and he was eventually
induced to come to Paris, where, after rilling various
appointments, he was elected to the chair of Compara-
tive Anatomy in 1795.
Cuvier's splendid career belongs mainly to the
history of biology. We are only concerned here in
noting how he came to be interested in geological
questions. He tells himself that some TerebratuLe
from the rocks at Fecamp suggested to him the idea
of comparing the fossil forms with living organisms.
When he settled in Paris, he pursued this idea,
never losing an opportunity of studying the fossils
to be found in the different collections. He began
by gathering together as large a series as he could
obtain of skeletons of living species of vertebrate
animals, as a basis for the comparison and determina-
tion of extinct forms. As a first essay in the new
domain which he was to open up to science, he read
to the Institute, at the beginning of 1796, a memoir
in which he demonstrated that the fossil elephant
belonged to a different species from either of the
living forms. Two years later, having had a few
bones brought to him from the gypsum quarries of
Montmartre, he saw that they indicated some quite
unknown animals. Further research qualified him
to reconstruct the skeletons, and to demonstrate their
Brongniart 365
entire difference, both specifically and generically, from
any known creatures of the modern world. He was
thus enabled to announce the important conclusion
that the globe was once peopled by vertebrate animals
which, in the course of the revolutions of its surface,
have entirely disappeared.
These discoveries, so remarkable in themselves, could
not but suggest many further inquiries to a mind
so penetrating and philosophical as that of Cuvier.
He narrates how he was pursued and haunted by
the desire to know why these extinct forms dis-
appeared, and how they had come to be succeeded
by others. It was at this point that he entered
upon the special domain of geology. He found that
besides studying the fossil bones in the cabinet, it
was needful to understand, in the field, the con-
ditions under which they have been entombed and
preserved. He had himself no practical acquaint-
ance with the structure and relations of rocks, but
he was fortunate in securing the co-operation of a
man singularly able to supply the qualifications in
which he was himself deficient.
Alexandre Brongniart (1770-1847) Cuvier's associate,
was a year younger than the great anatomist. Born
in Paris, he began his career early in life by endeav-
ouring to improve the art of enamelling in France.
Thereafter he served in the medical department of
the army until he was attached to the Corps of Mines,
and was made director of the famous porcelain factory
of Sevres. He had long given his attention to
minerals and rocks, and was eventually appointed
professor of mineralogy at the Museum of Natural
366 Cuvier and Brongniart
History. But his tastes led him also to study zoology.
Thus, among his labours in this field, he worked out
the zoological and geological relations of Trilobites.
There was consequently in their common pursuits, a
bond of union between him and Cuvier. They had
both entered upon a domain that was as yet almost
untrodden ; and each brought with him knowledge
and experience that were needful to the other.
Accordingly they engaged in a series of researches
in the basin of the Seine, which continued for some
years. Cuvier relates that during four years he made
almost every week an excursion into the country
around Paris, for the sake of studying its geological
structure. Particular attention was given to two
features, the evidence of a definite succession among
the strata, and the distinction of the organic remains
contained in them. At last the results of these in-
vestigations were embodied in a joint memoir by
Cuvier and Brongniart, which first appeared in the
year iSoS. 1
The two naturalists continued their researches with
great industry during the following years. An account
of these additional observations was read by them
before the Institute in April 1810, and was published
as a separate work with a map, sections, and plate of
fossils in i8n. 2 Referring afterwards to this conjoint
essay and its subsequent enlargement, Cuvier generously
wrote that though it bore his name, it had become
1 Journal des Mines, tome xxiii. (1808), p. 4.21.
2 Essai sur la Geographic Mineralogique des Environs de Paris, avec une
Carte geognostique et des Coupes de terrain, 410, 1 8 1 1 . An enlarged
edition of this separate work appeared in 1822.
Their work in the Paris Basin 367
almost entirely the production of his friend, from the
infinite pains which, ever after the first conception of
their plan, and during their various excursions, he
had bestowed upon the thorough investigation of all
the objects of the inquiry, and in the preparation of
the essay itself. 1 Brongniart's experience as a mining
engineer would naturally make him fitter than Cuvier
for the requirements of stratigraphical research.
It is not necessary for our present purpose to trace
the development of view shown by these observers
during the three years that elapsed between the appear-
ance of their first sketch and that of their illustrated
quarto memoir. It will be enough to note the general
characters of their first essay, and to see how far in
advance it was of anything that had preceded it.
After briefly describing the limits and general feat-
ures of the Seine basin, the authors proceed to show
that the formations which they have to consider were
deposited in a vast bay or lake, of which the shores
consisted of Chalk. They point out that the deposits
took place in a certain definite order, and can be easily
recognised by their lithological and palaeontological
characters throughout the district. They classify
them first broadly into two great groups, which they
afterwards proceed to subdivide into minor sections.
The first of these groups, covering the Chalk of the
lower grounds, consists partly of the plateau of lime-
stone without shells, and partly of the abundantly
shell-bearing Calcaire Grossier. The second group
comprises the gypseo-marly series, not found uniformly
distributed, but disposed in patches.
1 Difcours sur les Revolutions de la Surface du Globe, 6th edit. p. 294.
368 Cuvier and Brongniart
Starting from the Chalk of the north of France,
the two observers succinctly indicate the leading char-
acters of that deposit, its feeble stratification, chiefly
marked by parallel layers of dark flints, the varying
distances of these layers from each other, and the dis-
tinctive fossils. Putting together the organisms they
had themselves collected, and those previously ob-
tained by Defrance, they could speak of fifty species
of organic remains known to occur in the Chalk a
small number compared with what has since been
found. The species had not all been determined, but
some of them, such as the belemnites, had been noted
as different from those found in the " compact lime-
stone," or Jurassic series.
From the platform of Chalk, Cuvier and Brongniart
worked their way upward through the succession of
Tertiary formations. At the base of these, and resting
immediately on the Chalk, came the Plastic Clay a
deposit that in many respects presented strong con-
trasts to the white calcareous formation underneath it.
It showed no passage into that formation, from which,
on the contrary, it was always abruptly marked off,
and it yielded no organic remains. The two geologists
accordingly drew the sound inference that the clay and
the chalk must have been laid down under very
different conditions of water, and they believed that
the animals which lived in the first period did not
exist in the second. They likewise concluded that
the abrupt line of junction between the two forma-
tions might indicate a long interval of time, and
they inferred, from the occurrence of an occasional
breccia of chalk fragments at the base of the clay,
Their work in the Paris Basin 369
that the chalk was already solid when the clay was
deposited.
The next formation in ascending order was one of
sand and the Calcaire Grossier. It was shown to
consist of a number of bands or alternations of lime-
stone and marl ; following each other always in the
same order, and traceable as far as the two observers
had followed them. Some of the strata might diminish
or disappear, but what were below in one district were
never found above in another. "This constancy in
the order of superposition of the thinnest strata," the
writers remark, "for a distance of at least 12 myria-
metres (75 English miles), is in our opinion one of
the most remarkable facts which we have met with in
the course of our researches. It should lead to results
for the arts and for geology all the more interesting
that they are sure."
One of the most significant parts of the essay is the
account it gives of the method adopted by the explorers
to identify the various strata from district to district.
They had grasped the true principle of stratigraphy,
and had applied it with signal success. The passage
deserves to be quoted from its historical importance
in the annals of science : u The means which we have
employed, among so many limestones, for the recog-
nition of a bed already observed in a distant quarter,
has been taken from the nature of the fossils contained
in each bed. These fossils are generally the same in
corresponding beds, and present tolerably marked differ-
ences of species from one group of beds to another.
It is a method of recognition which up to the present
has never deceived us.
2 A
37 Cuvier and Brongniart
" It must not be supposed, however, that the differ-
ence in this respect between one bed and another is
as sharply marked off as that between the chalk and
the limestone. The characteristic fossils of one bed
become less abundant in the bed above and disappear
altogether in the others, or are gradually replaced
by new fossils, which had not previously appeared." 1
The authors then proceed to enumerate the chief
groups of strata composing the Calcaire Grossier,
beginning at the bottom and tracing the succession
upward. It is not necessary to follow them into
these details. We may note that, even at that time,
the prodigious richness of the lower parts of this
formation in fossil shells had been shown by the
labours of Defrance, who had gathered from them no
fewer than 600 species, which had been described
by Lamarck. It was remarked by Cuvier and Brong-
niart that most of these shells are much more unlike
living forms than those found in the higher strata.
These observers also drew, from the unfossiliferous
nature of the highest parts of the formation, the in-
ference that during the time when the Calcaire Grossier
was deposited slowly, layer after layer, the number of
shells gradually diminished until they disappeared, the
waters either no longer containing them or being un-
able to preserve them.
The gypseous series which succeeds offered to
Cuvier and Brongniart an excellent example of what
Werner termed a " formation," inasmuch as it pre-
sents a succession of strata markedly different from
each other, yet evidently deposited in one continuous
^-Journal des Mines, xxiii. p. 436.
Their work in the Paris Basin 371
sedimentation. Cuvier had already startled the world
by his descriptions of some of the extinct quadrupeds
entombed in these deposits. In calling attention to
the occurrence of these animals, the authors refer to
the occasional discovery of fresh-water shells in the
same strata, and to the confirmation thereby afforded
to the opinion of Lamanon and others, that the gypsum
of Montmartre and other places around Paris had been
deposited in fresh-water lakes.
They saw the importance of a thin band of marl
at the top of the gypseous series which, in spite of
its apparent insignificance, they had found to be trace-
able for a great distance. Its value arose partly from
its marking what would now be called a lithological
horizon, but even more from its stratigraphical in-
terest, inasmuch as it served to separate a lacustrine
from a marine series. All the shells below this seam
were found to be fresh-water forms. Those in the
seam itself were species of Tellina, and all those in
the strata above were, like that shell, marine. The
two geologists, struck by the marked difference of
physical conditions represented by the two sections
of the gypseous series, had tried to separate it
into two formations, but had not carried out the
design.
Higher up in the series, above a group of sands
and marine sandstones, an unfossiliferous siliceous
limestone, and a sandstone formation without shells,
Cuvier and Brongniart found a widespread fresh-water
siliceous limestone or millstone, specially characterised
by containing Limnea, Planorbis, and other lacustrine
shells.
37 2 Cumer and Brongniart
The youngest formation which they described was
the alluvium of the valleys, with bones of elephants
and trunks of trees.
Subsequent research has slightly altered and greatly
elaborated the arrangement made by Cuvier and
Brongniart of the successive Tertiary formations of
the Paris basin. But although the subdivision of the
strata into definite stratigraphical and palaeontological
platforms has been carried into far greater detail,
the broad outlines traced by them remain as true
now as they were when first sketched a century
ago. These two great men not merely marked out
the grouping of the formations in a limited tract of
country. They established on a basis of accurate
observation the principles of palaeontological strati-
graphy. They demonstrated the use of fossils for
the determination of geological chronology, and they
paved the way for the enormous advances which
have since been made in this department of science.
For these distinguished labours they deserve an
honoured place among the Founders of Geology.
Cuvier's contributions to zoology, palaeontology, and
comparative anatomy were so numerous and import-
ant that his share in the establishment of correct
stratigraphy is apt to be forgotten. But his name
must ever be bracketed with that of Brongniart for
the service rendered to geology by their conjoint
work among the Tertiary deposits of the Paris
basin.
Although Cuvier's researches among fossil animals,
and the principles of comparative anatomy which
he promulgated, contributed powerfully towards the
Cumer's Contributions to Geology 373
foundation and development of vertebrate palaeon-
tology as a distinct department of biology, his services
to geology proper may be looked upon as almost
wholly comprised in the joint essay with Brongniart.
Geology indeed had much fascination for him, and
he wrote a special treatise on it entitled A Discourse
on the Revolutions of the Surface of the Globed In
this work he maintains the opinion that the past
history of the earth has been marked by the occur-
rence of many sudden and widespread catastrophes,
exceeding in violence anything we can imagine at the
present day, whereby the surface of the land has been
overwhelmed by the sea, and its inhabitants have been
destroyed. Briefly reviewing the usual action of rain
and frost, brooks and rivers, the sea and volcanoes,
he comes to the conclusion that the former revolu-
tions were so stupendous that " the thread of Nature's
operations was broken by them, that her progress was
altered, and that none of the agents which she employs
1 In its first form it was prefixed to the Recherches sur les Ossemens
Fossiles as a Preliminary Discourse on the Theory of the Earth (1821).
It was afterwards published separately as the Discours sur les Revolutions
de la surface du Globe (1826). The work showed no marked ad-
vance in geological progress. Yet it went through six editions in the
author's lifetime, the latest (6th) corrected and augmented by him
appearing in 1830. The versions published in England were edited
and copiously annotated by Prof. Jameson of Edinburgh, whose notes
to the early editions supply some curious samples of his adherence to
Wernerianism. Cuvier was also the author of a Report on the Pro-
gress of the Natural Sciences, presented to the Emperor Napoleon in
1808, in which he expressed various vague and indefinite opinions on
geological questions. In his earlier years his geological bias was
decidedly towards Wernerianism (see the references in his Eloge on
De Saussure already cited, p. 308).
374 Cuvier and Lamarck
to-day could have sufficed for the accomplishment of
her ancient works." 1
The contrast between these opinions and those of
Lamarck on the same subject could not fail to im-
press the minds of their contemporaries. Cuvier was
a Cataclysmist, Lamarck an Evolutionist. The former
by his brilliant style, his social charm, and his in-
fluential position commanded the attention of the
world, so that his geological volume, though views
which it specially advocated have long since been aban-
doned, went through a number of successive editions,
besides being translated into English and German. It
became, indeed, one of the chief portals through which
the ordinary reader of the day made his acquaintance
with the science of geology. Lamarck's little Hydro-
geologie, on the other hand, met with no such success.
Though in many respects, in spite of its occasional
extravagance, a more philosophical treatise than
Cuvier's, it never reached a second edition, has never
been reprinted, and has almost sunk out of sight.
Notwithstanding the prominence assigned by Cuvier
to great cataclysms in the past history of our planet,
he recognised that there has been, on the whole, an
upward progress among the races of animals that have
successively flourished upon the earth. The oviparous
quadrupeds, for instance, preceded the viviparous.
But, unlike Lamarck, he set his face against evolution,
and refused to admit that the existing races can be
modifications of ancient forms, brought about by
local circumstances, change of climate or other causes ;
for if any such evolution had taken place, he claimed
1 Discours Prelimlnaire, p. xiii.
Cumer on the Deluge 375
that some evidence of it should have been found in
the shape of intermediate forms in the rocks. He
regarded species as permanent, though varieties might
arise. He offered a detailed argument to prove, from
physical facts and from the history of nations, that the
present continents are of modern date, and he entered
into an elaborate refutation of the alleged antiquity
of some peoples. He believed, with De Luc and
Dolomieu, in opposition to the opinions so well
expressed by Lamarck, that if any conclusion has
been well-established in geology, it is that a great
and sudden catastrophe befell the surface of the earth
some five or six thousand years ago, whereby the
countries inhabited by man were devastated and their
inhabitants were destroyed. At that time portions of
the sea-floor were upraised to form the present dry
land. But the rocks show that this land had previously
been inhabited, if not by man, at least by land-animals,
and thus that one preceding revolution, if not more,
had submerged these tracts and swept away their
population.
But it was the relation of such terrestrial revolu-
tions to the organic world which chiefly attracted the
great French naturalist. He could foresee the deeply
interesting problems that awaited solution in regard
to the alternation of sedimentary materials and the
succession of organic remains in the great series of
stratified formations, and he concludes his discourse
with these eloquent words : " What a noble task it
would be were we able to arrange the objects of the
organic world in their chronological order, as we have
arranged those of the mineral world. Biology would
376 Cumer's Eloges
thereby gain much. The development of life, the
succession of its forms, the precise determination of
those organic types that first appeared, the simultaneous
birth of certain species and their gradual extinction
the solution of these questions would perhaps en-
lighten us regarding the essence of the organism as
much as all the experiments that we can try with
living species. And man, to whom has been granted
but a moment's sojourn on the earth, would gain the
glory of tracing the history of the thousands of ages
which preceded his existence and of the thousands of
beings that have never been his contemporaries." x
Cuvier's brilliant career is well known, but I am
only concerned at present with those parts of it
which touch on geological progress. In 1802, the
year in which Lamarck's Hydrogeologie appeared, he
became perpetual Secretary of the Institute of France,
and it was in this capacity that he composed that
remarkable series of Eloges in which so much of
the personal history of the more distinguished men
of science of his time is enshrined. Eloquent and
picturesque, full of knowledge and sympathy, these
biographical notices form a series of the most
instructive and delightful essays in the whole range
of scientific literature. They include sketches of
the life and work of De Saussure, Pallas, Werner,
Desmarest, Sir Joseph Banks, Hatly, and Lamarck.
Five years after the appearance of the earliest con-
joint memoir by Cuvier and Brongniart, the structure
of the country which they described was still further
explored and elucidated by a man who afterwards
1 From the first edition of the Discours Preliminaire, 1821.
nOmalius cfHalloy 377
rose to fill an important place among the geologists
of Europe J. J. d'Omalius d'Halloy (1783-1875).
In 1813 this able observer read to the Institute a
memoir on the geology of the Paris basin and the
surrounding regions. 1 It corrected and extended the
work of his predecessors among the Tertiary forma-
tions, but its interest for our present purpose centres
mainly in its important contribution to the stratigraphy
of the Secondary rocks. He recognised the leading
subdivisions of the Cretaceous series, and actually
showed the extent of the system upon a map. He
likewise ascertained the stratigraphical relations and
range of the Jurassic system, which he called the
" old horizontal limestone," and which he correctly
depicted in its course outside the Chalk. His little
map, with its clear outlines and colours, is of historical
importance as being the first attempt to construct a
true geological map of a large tract of France. It
was not a mere chart of the surface rocks, like
Guettard's, but had a horizontal section, which showed
the Jurassic series lying unconformably upon the edges
of the Palaeozoic slates, and covered in turn by the
Gault and the Chalk.
1 Ann. des Mines, i. (1817), p. 251. He was the author of
numerous subsequent memoirs on the geology of Belgium and the
north of France, as well as of several excellent text books of the
science.
CHAPTER XII
THE Rise of Stratigraphical Geology in England. Michell, White-
hurst, William Smith, Thomas Webster, the Geological
Society of London, W. H. Fitton. Early teachers and text-
books. Influence of Lyell.
WHILE in France it was the prominence and richly
fossiliferous character of the Tertiary strata which
first led to the recognition of the value of fossils in
stratigraphy, and to the definite establishment of the
principles of Stratigraphical geology, in England a
similar result was reached by a study of the Secondary
formations, which are not only more extensively
developed there than the younger series, but display
more clearly their succession and persistence. But
in both countries the lithological sequence, being the
more obvious, was first established before it was con-
firmed and extended by a recognition of the value
of the evidence of organic remains.
Early in the eighteenth century Strachey published
the succession of formations from the Coal to the
Chalk (p. 194). Michell in 1760 gave a clear ac-
count of the stratified arrangement of the sedimentary
formations, describing their general characters and the
persistence of these characters for great distances, and
Michell on Geological Succession 379
showing that while on the flat ground the strata re-
main nearly level, they gradually become inclined as
they approach the mountains. 1 He pointed out that
the mountains are formed generally of the lower or
older rocks, while the more level ground lies usually
on the upper and nearly horizontal strata. He re-
marked further that the same sets of strata, in the
same order, are generally met with in crossing Britain
towards the sea, the direction of the ridge being
towards the north-north-east and south-south-west.
That he was familiar with the broad features of the
succession of the geological formations in England,
from the Coal-measures of Yorkshire up to the Chalk,
is shown by an interesting table which seems to have
been drawn up by him about 1788 or 1789, and
which was published after his death. 2
Michell enables us to form a clear conception of his
views by the following illustration. " Let a number
of leaves of paper," he remarks, " of several different
sorts or colours, be pasted upon one another ; then
bending them up into a ridge in the middle, conceive
them to be reduced again to a level surface, by a plane
so passing through them as to cut off all the part that
has been raised. Let the middle now be again raised a
little, and this will be a good general representation of
most, if not all, large tracts of mountainous countries,
together with the parts adjacent, throughout the whole
world. From this formation of the earth it will follow
that we ought to meet with the same kinds of earths,
stones, and minerals, appearing at the surface in long
1 Phil. Trans, vol. li. (1760), part ii. p. 582, et seq.
^Phll. Mag. vol. xxxvi. p. 102, and Hi. p. 186.
380 Whitekurst on Stratigraphy
narrow slips, and lying parallel to the greatest rise of
any long ridge of mountains ; and so, in fact, we find
them."
Contrast this clear presentation of the tectonic
structure of our mountains and continents with the
confused and contradictory explanation of the same
structure subsequently promulgated from Freiberg.
Michell clearly realised that the rocks of the earth's
crust had been laid down in a definite order, that
they had been uplifted along the mountain axes,
that they had been subsequently planed down, and
that their present disposition in parallel bands was
the result partly of the upheaval and partly of the
denudation.
Another English observer, whose name may be
mentioned here, is John Whitehurst (1713-1788) who
published in 1778 an "Inquiry into the Original
State and Formation of the Earth." This work was
the last effort of the fantastic English School of
Cosmogonists. Amid absurd speculations as to the
condition of Chaos and other equally visionary topics,
he wrote well on organic remains, and showed that he
clearly grasped the stratigraphical succession of the
formations in Derbyshire and other parts of England.
" The strata invariably follow each other," he remarks,
u as it were, in alphabetical order," and though they
may not be alike in all parts of the earth, neverthe-
less, " in each particular part, how much soever they
may differ, yet they follow each other in a regular
succession."
While the stratigraphical sequence of the geological
formations in England was thus partially realised by
William Smith, Father of English Geology 3 8 1
a few pioneers, its final establishment was the work
of William Smith (1769-1839) usually known as
the " Father of English geology." He definitely
arranged the rocks in their true order from the Killas
series (Cambrian and Silurian) of Wales up to the
Tertiary groups of the London basin. More particu-
larly he determined the subdivisions of the Secondary,
or at least of the Jurassic (Oolitic) rocks, and estab-
lished their order, which has been found applicable
not only to England but to the rest of Europe.
No more interesting chapter in scientific annals can
be found than that which traces the progress of this
remarkable man, who, amidst endless obstacles and
hindrances, clung to the idea which had early taken
shape in his mind, and who lived to see that idea
universally accepted as the guiding principle in the
investigation of the geological structure, not of Eng-
land only, but of Europe and of the globe.
William Smith came of a race of yeoman farmers
who for many generations had owned small tracts of
land in Oxfordshire and Gloucestershire. 1 He was
born at Churchill, in the former county, on 23rd March
1769, the same year that gave birth to Cuvier.
Before he was eight years old he lost his father.
After his mother married for the second time, he
seems to have been largely dependent upon an uncle
1 The biographical details are derived from the Memoirs of William
Smith, LL.D., by his nephew and pupil, John Phillips, 1844. The
biographer (1800-1874) became himself a leading geologist in
England and for the last eighteen years of his active and useful life
was the genial Reader and Professor of Geology in the University
of Oxford.
382 William Smith
for education and assistance. The instruction obtain-
able at the village school was of the most limited
kind. With difficulty the lad procured means to
purchase a few books from which he might learn the
rudiments of geometry and surveying. Already he
had taken to the observing and collecting of stones,
particularly of the well-preserved fossils whereof the
Jurassic rocks of his neighbourhood were full. He
came to be interested in questions of drainage and
other pursuits connected with the surface of the land,
and in spite of want of encouragement, made such
progress with his studies that at the age of eighteen
he was taken as assistant to a surveyor. But he had
no education beyond that of the village school and
what he had been able to acquire through his own
reading. This early defect crippled, to the end of
his life, his efforts to make known to the world the
scientific results he obtained.
Smith's capacity and steady powers of application were
soon appreciated in the vocation upon which he had
entered. Before long he was entrusted with all the
ordinary work of a land surveyor, to which were
added many duties that would now devolve upon a
civil engineer. From an early part of his professional
career, his attention was arrested by the great variety
among the soils with which he had to deal, and the
connection between these soils and the strata under-
lying them. He had continually to traverse the red
ground that marks the position of the Triassic marls
and sandstones in the south-west and centre of
England, and to pass thence across the clays and
limestones of the Lias, or to and fro among the
His early Geological studies 383
freestones and shales of the Oolites. The contrasts
of these different kinds of rock, the variations in
their characteristic scenery, and the persistence of
feature which marked each band of strata gave him
constant subjects of observation and reflection.
By degrees his surveying duties took him farther
afield, and brought him in contact with yet older forma-
tions, particularly with the Coal-measures of Somerset
and their dislocations. At the age of four-and-twenty,
he was engaged in carrying out a series of levellings
for a canal, and had the opportunity of confirming
a suspicion, which had been gradually taking shape
in his mind, that the various strata with which he
was familiar, though they seemed quite flat, were
really inclined at a gentle angle towards the east, and
terminated sharply towards the west, like so many
" slices of bread and butter." He took the liveliest
interest in this matter, and felt convinced that it
must have a far deeper meaning and wider application
than he had yet surmised.
His first start on geological exploration took place
the following year (1794) when, as engineer to a canal
that was to be constructed, he was deputed to accom-
pany two of the Committee of the Company in a
tour of some weeks duration, for the purpose of
gaining information respecting the construction, man-
agement, and trade of other lines of inland navigation.
The party went as far north as Newcastle, and came
back through Shropshire and Wales to Bath, having
travelled 900 miles on their mission. The young
surveyor made full use of the opportunities which this
journey afforded him. He had by this time satisfied
384 William Smith
himself that the stratigraphical succession, which he
had worked out for a small part of the south-west
of England, had an important bearing on scientific
questions, besides many practical applications of im-
portance. But it needed to be extended and checked
by a wider experience. u No journey, purposely con-
trived," so he wrote, " could have better answered
my purpose. To sit forward on the chaise was a
favour readily granted ; my eager eyes were never
idle a moment ; and post-haste travelling only put
me upon new resources, General views, under exist-
ing circumstances, were the best that could have been
taken, and the facility of knowing, by contours and
other features, what might be the kind of stratification
in the hills is a proof of early advancement in the
generalisation of phenomena.
" In the more confined views, where the roads
commonly climb to the summits, as in our start from
Bath to Tetbury, by Swanswick, the slow driving
up the steep hills afforded me distinct views of the
nature of the rocks ; rushy pastures on the slopes
of the hills, the rivulets and kind of trees, all aided
in defining the intermediate clays ; and while occasion-
ally walking to see bridges, locks, and other works,
on the lines of canal, more particular observations
could be made.
" My friends being both concerned in working coal,
were interested in two objects ; but I had three, and
the most important one to me I pursued unknown
to them ; though I was continually talking about
the rocks and other strata, they seemed not desirous
of knowing the guiding principles or objects of these
Early geological tour 385
remarks ; and it might have been from the many
hints, perhaps mainly on this subject, which I made
in the course of the journey, that Mr. Palmer jocosely
recommended me to write a book of hints." 1
We can picture the trio on this memorable
journey the young man in front eagerly scrutinizing
every field, ridge, and hill along each side of the
way, noting every change of soil and topography,
and turning round every little while, unable to
restrain his exuberant pleasure as his eye detected
one indication after another of the application of the
principles he had found to hold good at home, and
pointing them out with delight to his two sedate
companions, who looked at him with amusement,
but with neither knowledge of his aims nor sympathy
with his enthusiasm.
For six years William Smith was engaged in setting
out and superintending the construction of the Somer-
setshire Coal Canal. In the daily engrossing cares of
these duties it might seem that there could be little
opportunity for adding to his stores of geological
knowledge, or working out in more detail the prin-
ciples of stratigraphy that he had already reached.
But in truth these six years were among the most
important in his whole career. The constant and
close observation which he was compelled to give to
the strata that had to be cut through in making the
canal, led him to give more special attention to the
organic remains in them. From boyhood he had
gathered fossils, but without connecting them definitely
with the succession of the rocks that contained them.
1 Memoirs, p. 10.
386 William Smith
He now began to observe more carefully their dis-
tribution, and came at last to perceive that, certainly
among the formations with which he had to deal,
"each stratum contained organized fossils peculiar to
itself, and might, in cases otherwise doubtful, be
recognized and discriminated from others like it, but
in a different part of the series, by examination of
them." 1
It was while engaged in the construction of this
canal that Smith began to arrange his observations
for publication. He had a methodical habit of writ-
ing out his notes and reflections, and dating them.
But he had not the art of condensing his material,
and arranging it in literary form. Nevertheless, he
could not for a moment doubt that the results which
he had arrived at would be acknowledged by the
public to possess both scientific importance and prac-
tical value. Much of his work was inserted upon
maps, wherein he traced the position and range of
each of the several groups of rock with which he had
become familiar. He had likewise ample notes of
local sections, and complete evidence of a recognis-
able succession among the rocks. Not only could he
identify the strata by their fossils, but he could point
out to the surveyors, contractors, and other practical
men with whom he came in contact, how useful in
many kinds of undertakings was the detailed know-
ledge which he had now acquired. In agriculture,
in mining, in road-making, in draining, in the con-
struction of canals, in questions of water-supply, and
in many other affairs of everyday life, he was able
1 Memoirs, p. 1 5 .
As Engineer and Surveyor 387
to prove that his system of observation possessed
great practical utility.
In the year 1799, n ^ s connection with the Canal
Company came to an end. He was thereafter com-
pelled to put his geological knowledge to commercial
use, and to undertake the laborious duties of an
engineer and surveyor on his own account. Eventually
he found considerable employment over the whole
length and breadth of England, and showed singular
shrewdness and originality in dealing with the engineer-
ing questions which came before him. He was a
close observer of nature, and his knowledge of natural
processes stood him in good stead in his professional
calling. If he had to keep out the sea from low
ground, he constructed his barrier as nearly as possible
like those which the waves themselves had thrown up.
If he was asked to prevent a succession of landslips,
he studied the geological structure of the district and
the underground drainage, and drove his tunnels so
as to intercept the springs underneath. His nephew
and biographer tells us that his engagements in con-
nection with drainage and irrigation involved journeys
of sometimes 10,000 miles in a year.
Such continuous travelling to and fro across the
country served to augment enormously his minute
personal acquaintance with the geological structure of
England. He made copious notes, and his retentive
memory enabled him to retain a vivid recollection
even of the details of what he had once seen. But
the leisure which he needed in order to put his
materials together seemed to flee from him. Year
after year passed away ; the pile of manuscript rose
388 William Smith
higher, but no progress was made in the preparation
of the growing mass of material for publication.
In the year 1799, William Smith made the acquaint-
ance of the Rev. Benjamin Richardson, who, living in
Bath, had interested himself in forming a collection of
fossils from the rocks of the neighbourhood. Look-
ing over this collection, the experienced surveyor was
able to tell far more about its contents than the owner
of it knew himself. Writing long afterwards to Sedg-
wick, Mr. Richardson narrated how Smith could decide
at once from what strata they had respectively come,
and how well he knew the lie of the rocks on the
ground. " With the open liberality peculiar to Mr.
Smith," he adds, " he wished me to communicate this
to the Rev. J. Townsend of Pewsey (then in Bath),
who was not less surprised at the discovery. But we
were soon much more astonished by proofs of his own
collecting, that whatever stratum was found in any
part of England, the same remains would be found in
it and no other. Mr. Townsend, who had pursued the
subject forty or fifty years, and had travelled over the
greater part of civilized Europe, declared it perfectly
unknown to all his acquaintance, and, he believed,
to all the rest of the world. In consequence of
Mr. Smith's desire to make so valuable a discovery
universally known, I without reserve gave a card of
the English strata to Baron Rosencrantz, Dr. Mailer
of Christiania, and many others, in the year iBoi." 1
The card of the English strata referred to in this
letter was a tabular list of the formations from the Coal
up to the Chalk, with the thicknesses of the several
1 Memoirs, p. 31.
His original Table of Strata 389
members, an enumeration of some of their characteristic
fossils, and a synopsis of their special lithological
peculiarities and scenery. This table was drawn up
in triplicate by Mr. Richardson, at Smith's dictation,
in the year 1799, each of the friends and Mr. Towns-
end taking a copy. Smith's copy was presented by
him to the Geological Society of London in 1831.
Though not actually published, this table obtained
wide publicity. It showed that the fundamental prin-
ciples of stratigraphy had been worked out by William
Smith alone, and independently, before the end of the
eighteenth century. He had demonstrated, as his
friend and pupil Farey testified, " that the fossil pro-
ductions of the strata are not accidentally distributed
therein, but that each particular species has its proper
and invariable place in some particular stratum ; and
that some one or two or more of these species of fossil
shells may serve as new and more distinctive marks of
the identity of most of the strata of England/' 1 Had
Smith's table been printed and sold it would have
established his claim to priority beyond all possibility of
cavil. But even without this technical support, his
place among the pioneers of stratigraphy cannot be
gainsaid.
Notwithstanding the abundant professional employ-
ment which he obtained, Smith never abounded in
money. So keenly desirous was he to complete his
investigation of the distribution of the strata of Eng-
land, for the purpose of constructing a map of the
country, that he spent as freely as he gained, walking,
riding, or posting in directions quite out of the way
1 See note on p. 394.
39 William Smith
of his business. " Having thus emptied his pockets
for what he deemed a public object, he was forced to
make up, by night-travelling, the time he had lost, so
as not to fail in his professional engagements."
Stimulated by the kindly urgency of his friend
Richardson, who alarmed him by pointing out that if
he did not publish his observations, some one else
might anticipate him, Smith was prevailed upon to draw
up a prospectus of a work in which he proposed to give
a detailed account of the various strata of England and
Wales, with an accompanying map and sections. A
publisher in London was named, and the prospectus
was extensively circulated ; but it led to nothing.
Eventually Smith established himself in London as
the best centre for his professional work, and in 1805
he took a large house there, with room for the display
of his collections and maps, which were open to the
inspection of any one interested in such matters.
Among his materials he had completed a large county
map of Somersetshire, as a specimen of what might
be done for the different counties of England. This
document seems to have been exhibited at the Board
of Agriculture, and a proposal was made that he should
be permanently attached to the corps of engineers then
engaged in surveying the island. But the idea never
went farther. Not until thirty years later was it re-
vived by De la Beche, and pressed with such persever-
ance as to lead in the end to the establishment of the
present Geological Survey of Great Britain.
From 1799, when Smith first contemplated the pub-
lication of his observations, every journey that he
took was as far as possible made subservient to the
His geological Map of England 391
completion of his map of England. At last, but not
until the end of the year 1812, he found a publisher
enterprising enough to undertake the risk of engrav-
ing and publishing this map. The work was begun in
January 1813, and was published in August I8I5- 1
It was appropriately dedicated to Sir Joseph Banks,
President of the Royal Society, who had encouraged
and helped the author.
William Smith's map has long since taken its place
among the great classics of geological cartography. It
was the first attempt to portray on such a scale not
merely the distribution, but the stratigraphy of the
formations of a whole country. Well might D'Au-
buisson say of it that " what the most distinguished
mineralogists during a period of half a century had
done for a little part of Germany, had been undertaken
and accomplished for the whole of England by one
man ; and his work, as fine in its results as it is
astonishing in its extent, demonstrates that England is
regularly divided into strata, the order of which is
never inverted, and that the same species of fossils
are found in the same stratum even at wide distances."'
But it is not so much as a cartographical achieve-
ment that Smith's great map deserves our attention
at present. Its appearance marked a distinct epoch
in stratigraphical geology, for from that time some of
what are now the most familiar terms in geological
nomenclature passed into common use. Smith had no
scholarship ; he did not even cull euphonious terms
1 For the title and description of the map see p. 452, where refer-
ence will be found to the map of G. B. Greenough.
2 Tralte de Geognosit (1819), tome ii. p. 253.
39 2 William Smith
from Greek or Latin lexicons ; he was content to take
the rustic or provincial names he found in common
use over the districts which he traversed. Hence were
now introduced into geological literature such words
as London Clay, Kentish Rag, Purbeck Stone, Car-
stone, Cornbrash, Clunch Clay, Lias, Forest Marble.
By ingeniously colouring the bottom of each forma-
tion a fuller tint than the rest, Smith brought the
general succession of strata conspicuously before the
eye. Further, by the aid of vertical tables of the
formations and a horizontal section from Wales to
the vale of the Thames, he was able to give the details
of the succession which, for some twenty-four years,
he had been engaged in unravelling in every part of
the kingdom.
Of especial value and originality was his clear sub-
division of what is now known as the Jurassic system.
He did for that section of the geological record what
Cuvier and Brongniart had done for the Tertiary series
of Paris. After the first copies of the map had been
issued, he was able still further to subdivide and
improve his classification of these strata, introducing
among the new bands, Crag, Portland Rock, Coral
Rag, and Kellaways Stone. 1
In the memoir accompanying the map, the tabular
arrangement of the strata drawn up in 1799 was
inserted, with its column giving the names, so far as
he knew them, of the more characteristic fossils of
each formation.
To the laborious researches of William Smith we
are thus indebted for the first attempt to distinguish
1 Phillips, Memoirs, p. 146.
His professional reverses 393
the various subdivisions of the Secondary rocks, from
the base of the New Red Sandstone up to the Chalk,,
and for the demonstration that these successive plat-
forms are marked off from each other, not merely
by mineral characters, but by their peculiar assemblages
of organic remains. From his provincial terminology
come the more sonorous names of Purbeckian, Port-
landian, Callovian, Corallian, Bathonian, Liassic, which
are now familiar words in every geological text-book.
In his eagerness to make his map as complete and
accurate as was possible to him, Smith spent so freely
of his hardly-earned income that he accumulated no
savings against the day of trial, which came only too
soon. He had been induced to lay down a railway
on a little property which early in life he had purchased
near Bath, with the view of opening some new quarries
and bringing the building-stone to the barges on the
canal. Unfortunately the stone, on the continuance
and quality of which the whole success of the enter-
prise rested, failed. It became necessary to sell the
property, and thereafter the sanguine engineer was
left with a load of debt under which most men would
have succumbed. Struggling under this blow, he was
first compelled to part with his collections of fossils,
which were acquired by the Government and placed
in the British Museum. Next he found himself no
longer able to bear the expense of the house in London
which he had occupied for fifteen years. Not only
so, but hard fate drove him to sell all his furniture,
books and other property, keeping only the maps,
sections, drawings and piles of manuscript which were
so precious in his own eyes, but for which nobody
394 William Smith
would have been likely to give him anything. For
seven years he had no home, but wandered over the
north of England, wherever professional engagements
might carry him. His income was diminished and
fluctuating, yet even under this cloud of trial he
retained his quiet courage and his enthusiasm for
geological exploration.
That a man of Smith's genius should have been
allowed to remain in this condition of toil and poverty
has been brought forward as a reproach to his fellow-
countrymen. It may be doubted, however, whether
a man of his strong independence of character would
have accepted any pecuniary assistance, so long as
he could himself gain by his own exertions a modest
though uncertain income. It is not that his merits
were unrecognised in England, though perhaps the
appreciation of them was tardier than it might have
been. In 1818 a full and generous tribute to his
merits was written by Fitton, and appeared in the
Edinburgh Review for February in that year. 1 But
though his fame was thus well established, his financial
position remained precarious. He had gradually
formed a consulting practice as a mineral and geo-
logical surveyor in the north of England, and he
1 At the end of 1817 there seems to have been some inquiry
as to priority of discovery in regard to Smith's work. In the
following March, Mr. John Farey contributed to Tilloch's Philo-
sophical Magazine a definite statement of Smith's claims, showing
that the fundamental facts and principles he had established had
been freely made known by him to many people as far back as
1795, and that Farey himself, on 5th August 1 807, had published
an explicit notification of Smith's discoveries and conclusions as
to fossil shells in the article on Coal in Rees' Cyclopedia.
His figure and character 395
eventually settled at Scarborough. From 1828 to
1834 he acted as land-steward on the estate of
Hackness in the same district of Yorkshire. In
1831 he received from the Geological Society the
first Wollaston Medal, and the President of the
Society, Adam Sedgwick, seized the occasion to pro-
claim, in fervid and eloquent words, the admiration
and gratitude of all the geologists of England towards
the man whom he named " the father of English
geology." Next year a pension of jioo from the
Crown was conferred upon him. Honours now came
to him in abundance. But his scientific race was
run. He continued to increase his piles of manu-
script, but without methodically digesting them for
publication. He died on 28th August 1839, m t ^ ie
seventy-first year of his age.
William Smith was tall and broadly built, like the
English yeomen from whom he came. His face
was that of an honest, sagacious farmer, whose broad
brow and firm lips betokened great capacity and
decision, but would hardly have suggested the enthusi-
astic student of science. His work, indeed, bears
out the impression conveyed by his portrait. His
plain, solid, matter-of-fact intellect never branched
into theory or speculation, but occupied itself wholly
in the observation of facts. His range of geological
vision was as limited as his general acquirements. He
had reached early in life the conclusions on which
his fame rests, and he never advanced beyond them.
His whole life was dedicated to the task of extending
his stratigraphical principles to every part of England.
But this extension, though of the utmost importance
396 William Smith
to the country in which he laboured, was only of
secondary value in the progress of science.
Besides his great map of England, Smith published
also a series of geological maps, on a larger scale, of
the English counties, comprising in some instances
much detailed local information. He likewise issued
a series of striking horizontal sections (1819) across
different parts of England, in which the succession
of the formations was clearly depicted. These sections
may be regarded as the complement of his map,
and as thus establishing for all time the essential
features of English stratigraphy, and the main out-
lines of the sequence of the Secondary formations
for the rest of Europe. In another publication, Strata
Identified by Organised Fossils (1816), he gave a series
of plates, with excellent engraved figures of charac-
teristic fossils from the several formations. He
adopted in this work the odd conceit of having the
plates printed on variously coloured paper, to corre-
spond with the prevalent tint of the strata from
which the fossils came. He had no palaeontological
knowledge, so that the thin quarto, never completed,
is chiefly of interest as a record of the organisms
that he had found most useful in establishing the
succession of the formations.
There is yet another name that deserves to be
remembered in any review of the early efforts to group
the Secondary formations that of Thomas Webster
(I773-I844). 1 As far back as 181 1, this clever artist
1 Webster was born in the Orkney Islands, received his education
at Aberdeen, and came early in life to London. He practised as an
architect, and made journeys in England during which he devoted
Webster 397
and keen-eyed geologist began a series of investiga-
tions of the coast-sections of the Isle of Wight and
of Dorset, and continued them for three years. They
were published in 1815, the same year that Smith's
map made its appearance. 1 They were thus indepen-
dent of that work. Webster had already studied the
Tertiary formations of the Isle of Wight and had pub-
lished a remarkable memoir upon them in which he
recognised their alternations of fresh-water and marine
strata, 2 as had been done in the Paris basin. He now
threw into tabular arrangement the whole succession of
strata from the upper fresh-water (Oligocene) group
through the Lower Tertiary series to the Kimmeridge
shale in the Jurassic system. He clearly defined each
of the leading subdivisions of the Cretaceous series,
and prepared the way for the admirable later and more
detailed work of William Henry Fitton (i78o-i86i) 3
much time to geological enquiry. In 1826 he became House-secre-
tary and Curator to the Geological Society, and in 1841 was appointed
Professor of Geology in University College, London.
iSee Englefield's Isle of Wight (1815), p. 117.
2 Trans. Geol. Soc. vol. ii. This and his other memoirs are classic
contributions to the Secondary and Tertiary geology of England.
3 Fitton, though of English lineage, was born in Dublin. After
distinguishing himself at Trinity College there, he at first proposed to
enter the church, but his predilection for natural science turned him
into medicine, and he finally took the degree of M.D. and for some
years practised as a physician in Northampton. Early in life he
studied at Edinburgh, and acquired there under Jameson a love of
geological pursuits. Eventually, having married a lady possessed of
ample means, he retired from his profession, and established himself
in London, where his house became one of the scientific centres of his
time. From 1817 down to the middle of last century he continued
at intervals to contribute articles to the Edinburgh Review on the
398 Geological Society of London
to whom we are indebted for the first detailed and
accurate determination of the succession of strata and
their distinctive fossils, from the base of the Chalk
down into the Oolites, in the south of England and
the neighbouring region in France. More particularly
he showed the relations and importance of the Green-
sand formations, his memoirs on which are now among
the classics of English geology.
In concluding this sketch of the early progress of
stratigraphical geology in Britain I may refer to the
important influence exerted by the Geological Society
of London which was founded in 1 807 " to investigate
the mineral structure of the Earth." At that time the
warfare between the Neptunists and Plutonists still
continued, but there were many men, interested in the
study of geological subjects, who were weary of the
conflict of hypotheses, and who would fain devote their
time and energy to the accumulation of facts regard-
ing the ancient history of the globe, rather than to
the elaboration of theories to explain them. A few
such enquirers formed themselves into the Geological
Society, and soon attracted others around them until,
in a few years, they had established an active insti-
tution which became a centre for geological research
and discussion, published the contributions of its
progress of his favourite science. These essays showed him to be an
able and elegant writer, who was not only conversant with all the
advances in the geology of the day, but having also an intimate
acquaintance with the history and literature of the science, was able
by his criticism to exercise a guiding influence on his contemporaries.
His researches among the Greensand formations, on which his fame
rests as an original observer, were continued for twelve years from
1824 to 1836.
Cony b ear e and Phillips 399
members in quarto volumes, and eventually was
incorporated by Royal Charter as one of the leading
scientific bodies of the country. This society, which
has been the parent of others in different countries,
continues to flourish, and its publications, extending
over nearly a century, contain a record of original
researches which have powerfully helped the progress
of all branches of geology. Besides their papers issued
by the society, some of the early members published
separate works which greatly advanced the cause of
their favourite science. Among these early inde-
pendent treatises perhaps the most important was the
Outlines of the Geology of England and Wales by
W. D. Conybeare (1787-1857) and W. Phillips
(1775-1828) which appeared in 1822. In this excel-
lent volume all that was then known regarding the
rocks of the country, from the youngest formations
down to the Old Red Sandstone, was summarised in so
clear and methodical a manner as to give a powerful
impulse to the cultivation of geology in England.
From the outline given in this and the previous
Chapter, it will be seen that during the last two
decades of the eighteenth and the first four of the
nineteenth century, great progress was made in the
study of the stratigraphy of the Secondary and Tertiary
formations of France and England, while the principle
of the application of the evidence of organic remains
to the identification of these formations from district
to district was everywhere applied with signal success.
From the youngest alluvial deposits down through
the whole series of sedimentary rocks to the Car-
boniferous system, the clue had been obtained and
400 Rapid growth of Stratigraphy
put to use whereby the stratigraphical order could
be satisfactorily established from one country to
another. A prodigious impetus was now given to
the study of geology. The various stratified forma-
tions, arranged in their true chronological sequence,
were seen to contain the regular and decipherable
records of the history of our globe, which could be
put together with at least as much certainty as
faded manuscripts of human workmanship. The or-
ganic remains contained in them were found to be
not random accumulations, heaped together by the
catastrophes of bygone ages, but orderly chronicles of
old sea-floors, lake-bottoms, and land-surfaces. The
centre of gravity of geology was now rapidly altered,
especially in Western Europe. Minerals and rocks no
longer monopolized the attention of those who inter-
ested themselves in the crust of the earth. The petri-
fied remains of former plants and animals ceased to be
mere curiosities. Their meaning as historical docu-
ments was at last realised. They were seen to have a
double interest, for while they told the story of the
successive vicissitudes which the surface of the earth
had undergone, from remote ages down to the present,
they likewise unfolded an altogether new and mar-
vellous panorama of the progress of life upon that
surface. They had hitherto shared with minerals and
rocks the usage of the term " fossil." As their im-
portance grew, they were discriminated as " organized
fossils." But the rising tide of awakened interest, follow-
ing Lamarck's lead, swept away the qualifying participle,
and organic remains became sole possessors of the
term, as if they were the only objects dug out of the
Geological Text-Books 401
earth that were any longer worthy to be denominated
fossils.
While the whole science of geology made gigantic
advances during the nineteenth century, by far the most
astonishing progress sprang from the recognition of the
value of fossils. To that source may be traced the
prodigious development of stratigraphy over the whole
world, the power of working out the geological history
of a country, and of comparing it with the history of
other countries, the possibility of tracing the synchron-
ism and the sequence of the geographical changes of
the earth's surface since life first appeared upon the
planet. To the same source, also, we are indebted for
the rise of the science of Palaeontology, and the splendid
contributions it has made to biological investigation.
In the midst of the profusion, alike of blossom and of
/fruit, let us not forget the work of those who sowed
^*the seed of the abundant harvest which we are now
reaping. Let us remember the early suggestive essays
of Guettard, the pregnant ideas of Lehmann and
Fiichsel, the prescient pages of Giraud-Soulavie, the
brilliant work of Lamarck, Cuvier and Brongniart, and
the patient and clear-sighted enthusiasm of William
Smith.
To another feature in the rapid advance of geology
after these pioneers had gone to their rest, brief allusion
must here be made. The amount of ascertained fact
regarding the structure and history of the earth was
every year increasing at so rapid a rate that it became
necessary to prepare digests of it, for the use of those
who wished to be informed on these subjects or to
keep pace with the advance of knowledge. Hence
2 c
402 Geological Text-Books
arose in different countries, text-books, manuals and
other general treatises wherein an account was given of
the facts and principles of geological science. The
earlier works of this kind were in some cases a mere
reproduction of the system taught by Werner at Frei-
berg. Such were the Lehrbuch der Mineralogie (1801-
1803) of F. A. Reuss and the Treatise on Geognosy
(1808) by R. Jameson which formed the third volume
of the first edition of his System of Mineralogy. The
citations which have been made in Chapter VII. from
the Edinburgh Professor's volume may serve as illus-
trations of the Wernerian geognosy. But the great
advance made by the science during the first three
decades of last century, consequent on the development
of stratigraphy and the construction of geological maps
led to a complete change in the method of treatment
adopted in the text-books. In the excellent Traite de
Geognosie of J. F. d'Aubuisson de Voisons the transition
from Neptunianism to more modern and scientific views
is well displayed. In Germany various treatises ap-
peared in which the newer developments of geology
were discussed, the most voluminous and exhaustive
being the admirable Lehrbuch of C. F. Naumann. In
Belgium the JLUmem de Geologic of Omalius d'Halloy
and his Abrege went through successive editions, and did
good service in spreading a knowledge of the science.
In Italy the works of Breislak already cited (p. 257)
especially his Institutions Geologiques (Milan and Paris
1818) were useful additions to geological literature.
In England the Outlines of Conybeare and Phillips,
already noticed, deserves a special commendation.
Nine years later the Manual of Geology by H. T.
Lyell's Influence 403
De la Beche appeared (1831) and at once established
for itself a world-wide reputation for its ample and
clear presentation of the science. It was translated
into French and German, and an edition of it -was
also published in the United States. De la Beche's
other works, more particularly his Researches in Theo-
retical Geology (1831) and his How to observe in
Geology (1835), which showed his remarkable range
of acquirement, his scientific insight and his wide
practical acquaintance with rocks in the field, were
important contributions to the science. But of all the
English writers of general treatises on geology, the first
place must undoubtedly be assigned to Charles Lyell
(1797-1875) who exercised a profound influence on the
geology of his time in all English-speaking countries.
Adopting the principles of the Huttonian theory, he
developed them until the original enunciator of them
was nearly lost sight of. With unwearied industry he
marshalled in admirable order all the observations that
he could collect in support of the doctrine that the
present is the key to the past. With inimitable luci-
dity he traced the operation of existing causes, and
held them up as the measure of those which have acted
in bygone time. He carried Hutton's doctrine to its
logical conclusion, for not only did he refuse to allow
the introduction of any process which could not be
shown to be a part of the present system of Nature, he
would not even admit that there was any reason to
suppose the degree of activity of the geological agents
to have ever seriously differed from what it has been
within human experience. He became the great high
priest of Uniformitarianism a creed which grew to be
404 Charles Lyell
almost universal in England during his life, but which
never made much way in the rest of Europe, and which
in its extreme form is probably now held by few geolo-
gists in any country. Lyell's Principles of Geology will,
however, always rank as one of the classics of geology,
and must form an early part of the reading of every
man who would wish to make himself an accomplished
geologist. The last part of this work was ultimately
published as a separate volume, with the title of
Elements of Geology^ in which a large space was devoted
to an account of the stratified fossiliferous formations.
This treatise, diligently kept up to date by its author,
continued during his life-time to be the chief English
exposition of its subject, and the handbook of every
English geologist.
Lyell's function was mainly that of a critic and
exponent of the researches of his contemporaries, and
of a philosophical writer thereon, with a rare faculty of
perceiving the connection of scattered facts with each
other, and with the general principles of science. As
Ramsay once remarked to me, " We collect the data,
and Lyell teaches us to comprehend the meaning of
them." But Lyell, though he did not, like Sedgwick
and Murchison, add new chapters to geological history,
nevertheless left his mark upon the nomenclature and
classification of the geological record. Conceiving, as
far back as 1828, the idea of arranging the whole series
of Tertiary formations in four groups, according to their
affinity to the living fauna, he established, in conjunction
with Deshayes, who had independently formed a similar
opinion, the well-known classification into Eocene,
Miocene, and Pliocene. The first of these terms was
His Tertiary Classification 405
proposed for strata containing an extremely small pro-
portion of living species of shells ; the second for those
where the percentage of recent species was considerable,
but still formed the minority of the whole assemblage,
while the third embraced the formations in which living
forms were predominant. The scheme was a somewhat
artificial one, and the original percentages have had to
be modified from time to time, but the terms have
kept their place, and are now firmly planted in the
geological language of all corners of the globe.
CHAPTER XIII
PROGRESS of Stratigraphical Geology The Transition or Greywacke
formation resolved by Sedgwick and Murchison into the Cam-
brian, Silurian and Devonian systems. The Primordial Fauna
of Barrande. The pre-Cambrian rocks first begun to be set
in order by Logan.
THE determination of the value of fossils as chrono-
logical documents has done more than any other
discovery to change the character and accelerate the
progress of geological inquiry. No contrast can be
more striking than the difference between the con-
dition of the science before and after that discovery
was made. Before that time, while the Wernerian
classification of the rocks of the earth's crust prevailed,
there was really little stimulus to investigate these
rocks in their chronological relations to each other.
They were grouped, indeed, in a certain order, which
was believed to express their succession in time, but
their identification from one country to another pro-
ceeded on no minute study of their internal structure,
their fossil contents, or their tectonic relations. It
was thought enough if their mineral characters were
determined so that they could be placed in one or
other of the divisions of the Freiberg system. Hence,
Influence of Fossils on Stratigraphy 407
as was pointed in an earlier chapter, when an orthodox
disciple of Werner had relegated a mass of deposits
to the Transition series, or the Floetz or the Inde-
pendent Coal-formation, as the case might be, he
considered that all that was really essential had been
ascertained, and his interest in the matter came practi-
cally to an end.
But the extraordinary awakening which resulted from
the labours of Soulavie, Lamarck, Cuvier, Brongniart
and William Smith, invested the strata with a new
meaning. As stratigraphical investigations multiplied,
the artificiality and inadequacy of the Wernerian
arrangement became every day more apparent. Even
more serious than the attacks of the Vulcanists, and
the disclosure of eruptive granites and porphyries
among the Transition rocks, were the discoveries
made among the fossiliferous stratified formations.
It was no longer possible to crowd and crush these
rocks within the narrow limits of the Wernerian
system, even in its most modified and improved
form. The necessity for expansion and for adopting
a perfectly natural nomenclature and classification,
based upon the actually observed facts, as these
were successively ascertained, made itself felt especially
in England and in France. Hence arose the curiously
mongrel terminology which is now in use. Certain
formations were named from some prominent mineral
in them, such as Carboniferous. Others were dis-
criminated by some conspicuous variety of rock, like
the Cretaceous series. Some took their names from
a characteristic structure, like Oolitic, others from
their relative position in the whole series, as in the
40 8 Progress of Stratigraphy
case of Old Red Sandstone and New Red Sandstone.
Certain terms betrayed the country of their origin ,
as did William Smith's English provincial names,
like Gault, Kellaways Rock, and Lias.
The growth of the present stratigraphical nomen-
clature is thus eminently characteristic of the early
rise and progress of the study of stratigraphy in
Europe. Precisians decry this inartificial and hap-
hazard language, and would like to introduce a
brand new harmonious and systematic terminology.
But the present arrangement has its historical interest
and value, and so long as it is convenient and intelli-
gible, I do not see that any advantage to science
would accrue from its abolition. The method of
naming formations or groups of strata after districts
where they are typically developed has long been in
use and has many advantages, but it has not sup-
planted all the original names, and I for my part
hope that it never will.
With regard to what are now known as the Tertiary
and Secondary formations, the Wernerian " Floetz,"
under which they were all comprised, soon sank into
disuse. 1 But there was a long pause before the strata
of older date were subjected to the same diligent study.
1 One of the latest adaptations of the word was that of Keferstein
in his Tabellen fiber die vergleichende Geologic (1825). He frankly
threw over Wernerianism, but stuck to the pre- Wernerian Floetz,
which he arranged in five subdivisions, (i) Youngest Floetz,
alluvium, etc. ; (2) Tertiary Floetz, marls, gypsum, etc., of Paris,
Brown coal ; (3) Younger Floetz, or Chalk rocks, Chalk, Jura
Limestone, Greensand ; (4) Middle Floetz, or Muschelkalk Lias,
Keuper marl, Bunter sandstone, Zechstein ; (5) Old Floetz, or
Mountain Limestone Coal, Mountain Limestone.
The IVernerian Lithological Seqtience 409
For this delay various good reasons may be assigned.
We have seen that William Smith's researches went
down into the Coal-measures, but he had only a
general and somewhat vague idea of the sequence of
the rocks beneath that formation. In the table
accompanying his map (1812) he placed below the
Coal the Derbyshire Limestone followed by Red and
Dunstone, Killas or Slate and lastly Granite, Syenite^
and Gneiss. Some of these rocks were known to
be fossiliferous, but in general, throughout Western
Europe, they had been so disturbed and dislocated
that they no longer presented the proofs of their
sequence in the same orderly manner as had led to
the recognition of the succession of the younger
formations.
It will be remembered that in his original scheme of
classification Werner grouped some rocks as Primitive
(uranfangliche), and classed together as Floetz the
whole series of stratified formations between these and
the alluvial deposits. Further experience led him to
separate an intermediate group between the Primitive
and the Floetz, which he denominated Transition. He
considered that this group was " deposited during the
passage or transition of the earth from its chaotic to its
habitable state." 1 He recognised that it contains the
earliest organic remains, and believed it to include the
oldest mechanical deposits. He subdivided the Tran-
sition rocks rather by mineral characters than by
ascertained stratigraphical sequence. The hardened
variety of sandstone called greywacke formed by far
the most important member of the whole series, and
1 Jameson's Geognosy, p. 145 (1808).
410 Transition and Greywacke
was believed by Werner to mark a new geognostic
period when, instead of chemical precipitates, mechanical
accumulations began to appear.
The two Wernerian terms Transition and Greywacke
survived for some years after the commencement of
the great stratigraphical impulse in the early years of
last century. They formed a kind of convenient limbo
or No-man's Land, into which any group of rocks
might be thrown which obstinately refused to reveal its
relations with the rest of the terrestrial crust. Down
to the base of the Carboniferous rocks, or even to the
bottom of the Old Red Sandstone, the chronological
succession of geological history seemed tolerably clear.
But beneath and beyond that limit, everything be-
tokened disorder. It appeared well-nigh hopeless to
expect that rocks so broken and indurated, generally
so poor in fossils, and usually so sharply cut off from
everything younger than themselves, would ever be
made to yield up a connected and consistent series of
chapters to the geological record.
And yet these chapters, if only they could be written,
would be found to possess the most vivid interest.
They would contain the chronicles of the earlier ages
of the earth's history, and might perhaps reveal to man
the geography of the first dry land, the sites of the
most ancient seas, the positions of the oldest volcanoes,
the forms of the first plants and animals that appeared
upon the planet. There was thus inducement enough
to attack the old rocks that contained within their
stony layers such precious memorials.
It is not that the Transition rocks were entirely
neglected. The keen interest awakened in fossils led
Oldest Fossiliferous Rocks 411
to renewed search among the fossiliferous members of
that ancient series. A large number of organic remains
had been collected from Devonshire, Wales, the Lake
District, Rhineland, the Eifel, France, Sweden, Norway,
Russia, as well as from New York and Canada. These
fossils were distinct from those of the Secondary
formations, and they were obviously distributed, not
at random, but in groups which reappeared at widely
separated localities. 1 As yet, however, no clue had
been found to their stratigraphical sequence. Speci-
mens from what are now known as Cambrian, Silurian,
Devonian, and even Lower Carboniferous strata were
all thrown together as coming from the undefined
region of the Greywacke or Transition rocks. A task
worthy of the best energy of the most accomplished
geologist lay open to any man bold enough to under-
take to introduce among these rocks the same strati-
graphical method which had reduced the Secondary
and Tertiary formations to such admirable order, and
had furnished the means of comparing and correlating
these formations from one region to another. This
1 The amount and nature of the information in existence regarding
the Transition rocks or Greywacke, at the time when Murchison
entered upon their investigation, may be gathered from the summaries
contained in the contemporary general treatises on Geology. Even
as late as the spring of 1833, Lyell, after devoting about 300 pages
to the Tertiary formations, dismissed the Paleozoic series in twelve
lines (Principles of Geology, vol. iii. (1833), p. 326). One of the
fullest of the early descriptions of the older fossiliferous rocks, with
copious lists of fossils, will be found in the first edition of De la Beche's
Geological Manual (1831), p. 433, under the head of " Grauwacke
Group." But no attempt is there made to arrange the rocks strati-
graphically, and the fossil lists comprise organisms from all the older
Palaeozoic formations without discrimination of their horizons.
412 Roderick Itnpey Murchison
task was at last accomplished by two men, working
independently of each other in Wales and the border
counties of England. Murchison and Sedgwick, whose
observations on ancient volcanic action have already
been referred to, carried the principles of Cuvier,
Brongniart, and William Smith into the chaos of old
Greywacke, and succeeded in adding the Devonian,
Silurian and Cambrian chapters to the geological record,
thus establishing a definite order among the oldest
fossiliferous formations, and completing thereby Palaeo-
zoic stratigraphy.
Roderick Impey Murchison, who was born in Ross-
shire in 1792, belonged to a family that had lived
for centuries among the wilds of the north-western
Highlands of Scotland, and had taken part in much
of the rough life of that remote and savage region. 1
Entering the army when he was only fifteen years of
age, he served for a time in the Peninsular war, and
carried the colours of his regiment at the battle of
Vimieira. During the subsequent retreat to Corunna
he narrowly escaped being taken prisoner by the
French. On the conclusion of the Napoleonic wars,
seeing no longer any prospect of military activity or
distinction, he quitted the army, married, and for some
years devoted himself with ardour to fox-hunting, in
which his love of an open-air life and of vigorous
exercise could have full gratification. But he was
made for a nobler kind of existence than that of a
mere Nimrod. His wife, a woman of cultivated
tastes, had led him to take much interest in art and
1 The biographical details are taken from my Life of Sir Roderick /.
Murchison, ^ vols. 8vo, 1875.
His early Career 413
antiquities, and when Sir Humphry Davy, who also
recognised his qualities, urged him to turn his
attention to science, she strenuously encouraged him
to follow the advice. He at last sold his hunters,
came to London, and began to attend lectures on
chemistry and geology at the Royal Institution.
Murchison was thirty-two years old before he
showed any interest in science. But his ardent and
active temperament spurred him on. His enthusiasm
being thoroughly aroused, his progress became rapid.
He joined the Geological Society, and having gained
the goodwill of Buckland, went down to Oxford for his
first geological excursions under the guidance of that
genial professor. He then discovered what field-
geology meant, and learnt how the several parts of a
landscape depend for their position and form upon the
nature of the rocks underneath. He returned to
London with his zeal aflame, burning to put into
practice the principles of observation he had now been
taught. He began among the Cretaceous formations
around his father-in-law's home in Sussex, but soon
extended his explorations into Scotland, France and
the Alps, bringing back with him at the end of each
season a bundle of well-filled note-books from which
to prepare communications for the Geological Society.
These early papers, meritorious though they were, do
not call for any special notice here, since they marked
no new departure in geological research, nor added any
important province to the geological domain.
During six years of constant activity in the field,
Murchison, together with Sedgwick, worked out the
structure of parts of the west and north of Scotland,
414 Murchison
and toiled hard in disentangling the complicated
structure of the eastern Alps ; he also rambled with
Lyell over the volcanic areas of Central and Southern
France. Thereafter he determined to try whether the
" interminable greywacke," as he called it, could not
be reduced to order and made to yield a stratigraphical
sequence, like that which had been so successfully
obtained among younger formations. At the time
when be began, that is, in the summer of 1831,
absolutely nothing was known of the succession of
rocks below the Old Red Sandstone. It was an
unknown land, a pathless desert, where no previous
traveller had been able to detect any trace of a practic-
able track towards order, or any clue to a system of
arrangement that would enable the older fossiliferous
rocks of one country to be paralleled, save in the
broadest and most general way, with those of another.
Starting with his "wife and maid, two good grey
nags and a little carriage, saddles being strapped behind
for occasional equestrian use/' Murchison made his
way into South Wales. In that region, as was well
known, the stratigraphical series could be followed
down into the Old Red Sandstone, and within the
frame or border of that formation, greywacke was
believed to extend over all the rest of the Principality.
Let me quote a few sentences in which Murchison
describes his first entry into the domain with which his
fame is now so inseparably linked. " Travelling from
Brecon to Builth by the Herefordshire road, the gorge
in which the Wye flows first developed what I had not
till then seen. Low terrace-shaped ridges of grey rock,
dipping slightly to the south-east, appeared on the
His Silurian Quest 415
opposite bank of the Wye, and seemed to rise quite
conformably from beneath the Old Red Sandstone of
Herefordshire. Boating across the river at Cavansham
Ferry, I rushed up to these ridges, and, to my inex-
pressible joy, found them replete with Transition
fossils, afterwards identified with those at Ludlow.
Here then was a key, and if I could only follow this
out on the strike of the beds to the north-east, the case
would be good." l
With unerring instinct Murchison had realised that
if the story of old Greywacke was ever to be fully
told, a beginning must be made from some known and
recognisable horizon. It would have been well-nigh
useless to dive into the heart of the Transition hills,
and try to work out their complicated structure, for
even if a sequence could then have been determined,
there would have been no means of connecting it
with the already ascertained stratigraphical series,
unless it could be followed outwards to the Old
Red Sandstone. But by commencing at the known
base of that series, every fresh stage conquered was
at once a definite platform added to what had already
been established.
The explorer kept along the track of the rocks for
many miles to the north. No hunter could have
followed the scent of the fox better than he did the
outcrop of the fossiliferous strata, which he saw to come
out regularly from under the lowest members of the
Old Red Sandstone. Directed to the Wye by Buck-
land, he had the good-fortune to come at once upon
some of the few natural sections where the order
1 Life, vol. i. p. 182.
4i 6 Murchison
of the higher Transition rocks of Britain, and their
relations to the overlying formations, can be distinctly
seen. He pursued the chase northwards until he
lost the old rocks under the Triassic plains of
Cheshire. " For a first survey," he writes, " I had
got the upper grauwacke, so called, into my hands,
for I had seen it in several situations far from each
other, all along the South Welsh frontier, and in
Shropshire and Herefordshire, rising out gradually
and conformably from beneath the lowest member
of the Old Red Sandstone. Moreover, I had ascer-
tained that its different beds were characterized by
peculiar fossils, ... a new step in British geology.
In summing up what I saw and realised in about
four months of travelling, I may say that it was
the most fruitful year of my life, for in it I laid
the foundation of my Silurian system. I was then
thirty-nine years old, and few could excel me in
bodily and mental activity." 1
Not only did the work of these four momentous
months mark a new step in British geology. It
began the lifting of the veil from the Transition
rocks of the whole globe. It was the first successful
foray into these hitherto intractable masses, and pre-
pared the way for all that has since been done in de-
ciphering the history of the most ancient fossiliferous
formations, alike in the Old World and in the New.
Contenting himself with a mere announcement of
his chief results at the first meeting of the British
Association, held in York in 1831, Murchison gave
a brief outline of his subdivisions of the Upper
1 Op. clt. pp. 183, 192.
Establishes the Silurian system 417
Greywacke to the Geological Society in the spring
of I833. 1 He continued to toil hard in the field,,
mapping on the ground his various formations, and
making careful sections of their relations to each
other. Every fresh traverse confirmed the general
accuracy of his first observations, and supplied him
with further illustrations of the persistence and dis-
tinctness of the several groups into which he had
subdivided the Greywacke. At the beginning of
1834, he was able to present a revised and corrected
table of his stratigraphical results, each formation
being defined by its lithological characters and organic
remains, and the subdivisions being nearly what they
still remain. 2 The Ludlow rocks are shown to pass
upward into the base of the Old Red Sandstone,
and downward into the Wenlock group, which in
turn is succeeded below by the Horderley and May
Hill rocks, followed by the Builth and Llandeilo
flags. By the summer of 1835, at tne instigation
of Elie de Beaumont and other geological friends, he
had made up his mind as to the name that should
be given to this remarkable assemblage or system
of formations which he had disinterred from out of
the chaos of Greywacke. Following the good rule
that stratigraphical terms are most fitly formed on
a geographical basis with reference to the regions
wherein the rocks are most typically developed, he had
looked about for some appropriate and euphonious
term that would comprise his various formations
and connect them with that borderland of England
^Proc. Geol. Soc. vol. i. (1833), p. 474.
'id. vol. ii. (1834), P- IJ -
2 D
4i 8 Murchison
and Wales where they are so copiously displayed.
This territory was in Roman times inhabited by
the tribe of the Silures, and so he chose the term
Silurian a word that is now familiar to the geo-
logists of every country. 1
At the same time Murchison published a diagram-
matic section of his classification which, except in one
particular, has been entirely sustained by subsequent
investigation. He there groups the whole series of
formations as the Silurian system, which he divides
into Upper and Lower, drawing the line of separation
where it still remains. In the upper section come the
Ludlow and Wenlock rocks ; in the lower the Caradoc
and Llandeilo. The base of the series, however, is
made to rest unconformably on a series of ancient
slaty greywackes. No such base exists, for the Llandeilo
group passes downward into a vast series of older
sediments. At that time, however, both Murchison
and Sedgwick believed that a strongly marked separa-
tion lay between the Silurian System and the rocks
lying to the west of it.
Murchison used to maintain, with perfect justice,
that he had succeeded in his task, because he had
followed the method which had led William Smith
to arrange so admirably the Secondary formations of
England. He was able to show that, apart from mere
lithological differences, which might be of only local
value, his formations were definitely characterized, each
by its peculiar assemblage of organic remains. If
Smith's labours had not only brought the Mesozoic
rocks of England into order, but had furnished a
1 Phil. Mag. July 1835, p. 48.
Prepares his Silurian Monograph 419
means of dealing in like fashion with the rocks of the
same age in other countries, there seemed no reason
why the palaeontological succession, found to distinguish
the greywacke in England and Wales, should not be
equally serviceable among the Transition rocks of
Europe and even of America. And if this result
should be achieved, Murchison might fairly claim that
he had added a series of new and earlier chapters to
the geological history of the globe.
The various brief communications to the Geological
Society, after the first discoveries in 1831, though
they had made geologists familiar with the main results
of Murchison's work, only increased their desire to
know the detailed observations on which his general-
isations were founded, and more particularly to have
complete information as to the assemblages of organic
remains which he had discovered. Previous collec-
tions from the Transition rocks were generally of little
service for stratigraphical purposes, because those of
widely separate horizons had all been mixed together.
But Murchison's specimens had been carefully gathered,
with the view of sustaining his classification, and for
the purpose of forming a basis of comparison between
the Transition rocks of Britain and those of other
countries. Early in the course of his wanderings along
the Welsh border, he had been urged to prepare a full
and more generally accessible account of his labours
than was offered in the publications of a learned Society.
Accordingly, adding this task to his other engagements,
he toiled at the making of a big book, until at last,
towards the end of the year 1838, that is, about seven
years from the time when he broke ground by the
420 Murchison
banks of the Wye, he published his great work, The
Silurian System, a massive quarto of 800 pages, with
an atlas of plates of fossils and sections, and a large
coloured geological map.
The publication of this splendid monograph forms a
notable epoch in the history of modern geology, and
well entitles its author to be enrolled among the founders
of the science. For the first time, the succession of
fossiliferous formations below the Old Red Sandstone
was shown in detail. Their fossils were enumerated,
described and figured. It was now possible to carry
the vision across a vast series of ages, of which hitherto
no definite knowledge existed, to mark the succession
of their organisms, and thus to trace backward, far
farther than had ever before been possible, the history
of organised existence on this globe.
It has already been pointed (ante p. 268) that while
carefully working out the stratigraphy of the region,
Murchison had come upon various masses of eruptive
rock, some of which he recognised as intrusive, while
others he saw to be lavas and ashes that had been
ejected over the floor of the ancient ocean. In this
way he was able to present a picture of extraordinary
interest, in which the geologist could mark the position
of the old seas, trace the distribution of their organisms,
and note the sites of their volcanoes.
Even before the advent of his volume, the remark-
able results which he had succeeded in obtaining had
become widely known, and had incited other observers
all over the world to attack the forbidding domain of
Greywacke. In France, his classification had been
adopted, and applied to the elucidation of the older
Adam Sedgwick 421
fossiliferous rocks by Elie de Beaumont and Dufr6noy,
who were then engaged in constructing their geo-
logical map of that country (p. 456). In Turkey it
had been similarly made available by Boue and De
Verneuil. Forchhammer had extended it to Scandi-
navia. Featherstonhaugh and Rogers had applied it
in the United States. Thus within a few years, the
Silurian system was found to be developed in all
parts of the world, and Murchison's work furnished
the key to its interpretation.
Let us now turn to the researches that were in
progress by another great master of English geology,
simultaneously with those of Murchison. Adam Sedg-
wick belonged to a family that had been settled for 300
years or more in the Dale of Dent, a picturesque
district which lies along the western border of York-
shire. To the end of his long and active life his heart
ever turned with fondness to the little valley where he
first saw the light, and to the kindly dalesmen among
whom he spent his boyhood. He remained to the end
a true dalesman himself, with all the frankness of
nature, mirthfulness and loyalty, so often found among
the natives of these pastoral uplands. He was born in
the year 1785, his father being the Vicar of Dent.
After receiving his school education at the neighbour-
ing little town of Sedbergh, he went to Trinity College,
Cambridge, which thenceforth became his home to the
end of his life. At the age of thirty-three he was
elected to the Woodwardian Professorship of Geology.
Up to that time, however, he had shown no special
interest in geological pursuits, and though he may have
read a little on the subject, his knowledge of it was
422 Sedgwick
probably not greater than that of the average college
Fellow of his day. But his appointment as Professor
awakened his dormant scientific proclivities, and he at
once threw himself with all his energy and enthusiasm
into the duties of his new vocation. Gifted with
mental power of no common order, which had been
sedulously trained in a wide range of studies, possessing
a keen eye for the geological structure of a region,
together with abundant bodily prowess to sustain him
in the most arduous exertions in the field, eloquent,
witty, vivacious, he took at once the place of promin-
ence in the University which he retained to the last,
and he came with rapid strides to the front of all who
in that day cultivated the infant science of geology in
England.
What little geology Sedgwick knew, when he became
a professor of the science, seems to have been of a
decidedly Wernerian kind. He began his geological
writings with an account of the primitive ridge and its
associated rocks in Devon and Cornwall. His earliest
paper might have been appropriately printed in the
first volume of the Memoirs of the Wernerian Society.
In later years, referring to his Neptunist beginnings, he
confessed that " for a long while I was troubled with
water on the brain, but light and heat have completely
dissipated it," and he spoke of " the Wernerian non-
sense I learnt in my youth." 1 It was by his own
diligent work in the field that he came to a true
perception of geological principles. His excursions
carried him all over England, and enabled him to
l Life and Letters of Adam Sedgwick, by J. W. Clark and T. M'K.
Hughes, vol. i. p. 284.
Conjoint labours with Murchison 423
bring back each season a quantity of specimens for his
museum, and a multitude of notes from which he
regaled the Cambridge Philosophical Society with an
account of his doings. Eventually he joined the
Geological Society of London, and found there a wider
field of action. After a time, Murchison also became
a fellow of that Society, and he and Sedgwick soon
formed a close intimacy. This friendship proved to be
of signal service to the cause of geological progress.
The two associates were drawn towards the same
departments of investigation. They began their co-
operation in the year 1827 by a journey through the
west and north of Scotland, and from that time onward
for many years they were constantly working together
in Britain and on the Continent of Europe.
It would be interesting, but out of place here, to
linger over the various conjoint labours of these two
great pioneers in Palaeozoic geology. We are only
concerned with what they did, separately and in con-
junction, towards the enlargement of the geological
record and the definite establishment of the Palaeozoic
systems. Sedgwick began his work among the older
fossiliferous formations by attacking the rugged and
complicated region of Cumberland and Westmoreland,
commonly known as the Lake District, and in a series
of papers communicated to the Geological Society he
worked out the general structure of that difficult
tract of country. Though fossils had been found
in the rocks, he did not at first make use of them
for purposes of stratigraphical classification. He ascer-
tained the succession of the great groups of strata
by noting their lithological characters. One of the
424 Sedgwick and Murchison
most remarkable features of his investigation has been
above referred to (p. 266) the recognition of volcanic
rocks intercalated among the ancient marine sediments
of the Lake District. These rocks, since so fully
worked out, and now known as the " Borrowdale
Volcanic Series," of Lower Silurian age, were first
assigned to their true origin by Sedgwick, who thus
made an important contribution to the progress of
volcanic geology.
By a curious coincidence, Sedgwick and Murchison
both broke ground in Wales during the summer of
1831. But while Murchison determined to work his
way downward, from the known horizons of the Old
Red Sandstone of South Wales into the greywacke
below, Sedgwick, with characteristic dash, made straight
for the highest, ruggedest and most complicated tract
of North Wales. Returning to the same ground the
following year, he plunged into the intricacies of the
older Palaeozoic rocks, and succeeded in disentangling
their structure, tracing out their flexures and disloca-
tions, and ascertaining the general sequence of their
principal subdivisions. It was a splendid achievement,
which probably no other man in England at that time
could have accomplished.
But valuable as this work was, as a contribution to
the elucidation of the tectonic geology of a part of
Britain, it had not yet acquired importance in general
stratigraphy. In the first place, Sedgwick's groups
of strata were mere lithological aggregates. They
possessed as yet no distinctive characters that would
allow of their being adopted in the interpretation of
other countries, or even in distant parts of Britain.
Their respective work in Wales 425
They contained fossils, but these had not been made
use of in defining the subdivisions. There was thus
neither a basis for comparison with other regions, nor
for the ascertainment of the true position of the North
Welsh rocks in the great territory of Greywacke. In
the second place, there was no clue to the connection of
these rocks with any known formation, for they were
separated from everything younger than themselves
by a strong unconformability. The Carboniferous and
Old Red Sandstone strata were found to lie on the
upturned edges of the older masses, and it was im-
possible to say how many intervening formations were
missing.
Murchison's researches, on the other hand, brought
to light the actual transition from the base of the Old
Red Sandstone into an older series of fossiliferous
formations underneath. There could, therefore, be no
doubt that part at least of his Silurian system was
younger than Sedgwick's series in North Wales. And
as he found what appeared to be older strata emerging
from underneath his system, and seeming to stretch
indefinitely into the heart of Wales, he naturally
believed these strata to be part of his friend's domain,
and at first left them alone. Such, too, was Sedgwick's
original impression. The two fellow-workers had not
drawn a definite boundary between their respective
territories, but they agreed that the Silurian series was
less ancient than the rocks of North Wales.
As a distinct name had been given to what they
believed to be the younger series, Murchison urged
his associate to choose an appropriate designation for
what they regarded as the older, and in the 4 summer
426 Cambrian and Silurian Controversy
of 1835 the term " Cambrian " was selected. 1 By this
time Murchison had learnt that no hard and fast line
was to be drawn between the bottom of the Silurian
and the top of the Cambrian series. " In South Wales
he had traced many distinct passages from the lowest
member of the ' Silurian system ' into the underlying
slaty rocks now named by Professor Sedgwick the
Upper Cambrian." Sedgwick, on the other hand,
confessed that neither in the Lake District nor in
North Wales was the stratigraphical succession unbroken,
and that in these regions it was impossible to tell " how
many terms are wanting to complete the series to the
Old Red Sandstone and Carboniferous Limestone." :
He adopted a threefold subdivision into Lower, Middle,
and Upper Cambrian, but this classification rested
merely on mineral characters, no attempt having yet
been made by him to determine how far each of his
subdivisions was defined by distinctive fossils.
Eventually it was ascertained that the organic remains
in the upper part of the Cambrian system were the
same as those found in the Lower Silurian formations
as defined by Murchison. It became obvious that the
one series was really the equivalent of the other, and
that they ought not to be classed under separate names.
The officers of the Geological Survey, working from
the clearly defined Silurian formations, could draw no
line between these and those of North Wales, which
Sedgwick had classed as Cambrian. Finding the same
1 From " Cambria," the old name of Wales. Brit. Assoc. August
i835,P/5*7. Mag. vol. vii. (December 1835), P- 4 8 3 "On the Silurian
and Cambrian Systems" by A. Sedgwick and R. I. Murchison.
2 Op. at.
Joachim Barrande 427
fossils in both, they felt themselves constrained to
class them all under the same designation of Silurian.
Murchison, of course, had no objection to the indefinite
extension of his system. Sedgwick, however, after
some delay, protested against what he considered
to be an unjustifiable appropriation of territory which
he had himself conquered. And thus arose a mis-
understanding between these two old comrades, which
deepened ere long into a permanent estrangement.
It is not my intention to enter here into the details
of this unhappy controversy. 1 My only object in
referring to it is to point out how far we are indebted
to Sedgwick for the establishment of the Cambrian
system. He eventually traced through a part of the
Welsh border a marked unconform ability between the
Upper Silurian formations and everything below them,
and he proposed that his Cambrian system should
be carried up to that physical break, and should thus
include Murchison's Lower Silurian formations. But
as these formations had been defined stratigraphically
and palaeontologically before he had been able to get
his fossils from North Wales examined, they obviously
had the right of priority. And the general verdict
of geologists went in favour of Murchison.
While this dispute was in progress in Britain, a
remarkable series of investigations by Joachim
Barrande (1799-1883) had made known the extra-
ordinary abundance and variety of Silurian fossils in
Bohemia. This distinguished observer not only re-
cognised the equivalents of Murchison's Upper and
1 1 have already given a full and, I believe, impartial account of it
in my Life of Murchison.
428 The Primordial Fauna
Lower Silurian series, but found below that series a
still older group of strata, characterized by a different
assemblage of fossils, which he termed the first or
Primordial fauna. It was ascertained that represen-
tatives of this fauna occur in Wales among some of
the divisions of Sedgwick's Cambrian system, far below
the Llandeilo group which formed the original base
of the Silurian series. Eventually, therefore, since
the death of the two great disputants, there has been
a general consensus of opinion that the top of the
Cambrian system should be drawn at the upper limit
of the Primordial fauna. 1
By this arrangement, Sedgwick's name is retained for
an enormously thick and varied succession of strata
which possess the deepest interest, because they con-
tain the earliest records yet discovered of organised
existence on the surface of our globe. It was Sedg-
wick who first arranged the successive groups of strata
in North Wales, from the Bala and Arenig rocks
down into the depths of the Harlech anticline. His
classification, though it has undergone some slight
modification, remains to this day essentially as he left
it. And thus the name which he selected for his
system, and which has become one of the household
words in geological literature, remains with us a
memorial of one of the most fearless, strenuous, gentle
1 It has been proposed by Professor Lapworth that the strata named
by Murchison Lower Silurian and claimed by Sedgwick as Upper
Cambrian, should be taken from both and be given a new name,
" Ordovician." But this proposal is fair to neither disputant. By
all the laws that regulate scientific priority, the strata which were
first separated by Murchison and distinguished by their fossils, should
retain the name of Lower Silurian which he gave them.
The ancient Greywacke 429
and lovable of all the master minds who have shaped
geological science into its present form.
By the establishment of the Cambrian and Silurian
systems a vast stride was made in the process of
reducing the chaos of Greywacke into settled order.
But there still remained a series of rocks in that chaos
which could not be claimed as either Cambrian or
Silurian, and did not yield fossils which would show
them to be Carboniferous. Before any dispute arose
between Sedgwick and Murchison as to the respective
limits of their domains in Wales, they were led to
undertake a conjoint investigation which resulted in
the creation of the Devonian system. The story of
the addition of this third chapter to early Palaeozoic
history may be briefly told.
It had long been known that Greywacke or Transi-
tion rocks cover most of the counties of Devon and
Cornwall. Closer examination of that region had shown
that a considerable tract of Greywacke, now known
as Culm-measures, contains abundant carbonaceous
material, and even yields fossil plants that were recog-
nised as identical with some of those in the Carboni-
ferous system. It was at first supposed by De la Beche
that these plant-bearing rocks lie below the rest of the
Greywacke of that part of the country. Murchison,
however, from the evidence of his clear sections in the
Silurian territory, felt convinced that there must be
some mistake in regard to the supposed position of
these rocks, for he had traversed all the Upper Grey-
wacke along the Welsh border, and had found it to
contain no land-plants at all, but to be full of marine
shells. He induced Sedgwick to join him in an
43 Sedgwick and Murchison in Devonshire
expedition into Devonshire. The two associates, in
the course of the year 1836, completely succeeded in
proving that the Culm-measures, or Carboniferous
series, lay not below but above the rest of the Grey-
wacke of the south-west of England. But what was
that Greywacke, and what relation did it bear to the
rocks which had been reduced to system in Wales ?
The structure of the ground in the south-west of
England is by no means simple, and, indeed, is not
completely understood even now. The rocks have
been much folded, cleaved, crushed, and thrust over
each other. But besides these subsequent changes,
they present a great contrast in their lithological
characters to the Old Red Sandstone on the opposite
side of the Bristol Channel. Neither Sedgwick nor
Murchison could find any analogy between the Devon-
shire Greywacke and the red sandstones, conglomerates
and marls which expand into the Old Red Sandstone
of South Wales, and lie so clearly between the Car-
boniferous Limestone above and the Upper Silurian
formations below. Nor could Murchison see a re-
semblance between that Greywacke, or its fossils,
and any of his Silurian rocks. With their twisted
and indurated aspect, the Devonshire rocks looked so
much older than the gently inclined Silurian groups
by the banks of the Wye, that both he and Sedgwick
thought they more resembled the crumpled and broken
rocks of North Wales, and they accordingly first
placed them in the upper and middle parts of the
Cambrian system. 1
This correlation, however, was made mainly on
l Prof. Geol. Soc. ii. (1837), p. 560.
William Lonsdale 431
lithological grounds. The Devonshire rocks were not
without fossils, and considerable collections of these
had already been gathered by different residents in
the county, but no one had yet endeavoured to
make a comparison between them and those of
known stratigraphical horizons elsewhere. This task
was undertaken at last by William Lonsdale (1794-
1871), who towards the end of the year 1837 came
to the conclusion that the greywacke and limestone
of South Devonshire, judged by their fossil contents,
must be intermediate between the Silurian and the
Carboniferous formations, that is, on the parallel of
the Old Red Sandstone of other parts of Britain.
Such a decision from a skilled palaeontologist raised
up some serious difficulties, which completely non-
plussed the two able geologists who the year before
had gone so gaily down to the south-west of Eng-
land to set matters right there. It seemed to them
as if Lonsdale's opinion was opposed to what had
been regarded as definitely settled in the stratigraphy
of the older stratified rocks. For two years they
continued in complete uncertainty as to the solution
of the problem. But at last after the examination of
innumerable specimens, endless discussion, and inter-
minable correspondence, they came to adopt Lonsdale's
views. They saw that the abundantly fossiliferous
rocks of South Devon contained, in their lower
members, fossils that reminded them of Silurian types,
while in their upper members, they yielded species
that were common also to the Carboniferous Lime-
stone. The two geologists therefore recognised in
these rocks an intermediate series of strata, containing
43 2 Establishment of the Devonian System
a marine fauna which must have flourished between
the Silurian and the Carboniferous periods. That fauna
was not represented in the Old Red Sandstone, which,
with its traces of land-plants and remains of ganoid
fishes, appeared to have been accumulated under other
geographical conditions. To distinguish the series of
rocks containing this well-marked facies of marine
organisms, they chose the name " Devonian," from
the county where these rocks were originally studied
and where their true position was first ascertained. 1
The authors claimed that the establishment of the
Devonian system was " undoubtedly the greatest
change which has ever been attempted at one time
in the classification of British rocks.' 1 But it was far
more than that. It was the determination of a new
geological series of world-wide significance, the un-
folding of a new chapter in the geological annals of
our globe. Soon after Sedgwick and Murchison had
finally announced to the Geological Society their
reform of the geology of Devonshire, they started
for Rhineland, the Harz and Fichtelgebirge, and
succeeded in demonstrating that the Devonian system
is more extensively and completely developed there
than in its original Devonshire home.
I have dwelt on those labours of Sedgwick and
Murchison which more especially place their names
among those of the founders of geology. But besides
these exploits they each accomplished a vast amount
of admirable work, and helped thereby to widen the
bounds and strengthen the foundations of the science
to which they devoted their lives. To enter upon
1 Trans. Geol. Soc., 2nd ser. vol. v. pp. 688, 701 (April 1839).
Personal characteristics of Mure his on 433
the consideration of these further achievements, how-
ever, would lead me beyond the limits to which this
volume must be restricted.
Murchison, who had succeeded De la Beche in
1855 as Director-General of the Geological Survey
of Great Britain, held that office until his death in
1871. To the last, he retained the erect military
bearing of his youth, and even under the weight of
threescore years and ten could walk a dozen of miles
and keep a keen eye on all the topographical and
geological features of the surrounding hills. Tali
and dignified in manner, with much of the formal
courtesy of an older time, he might seem to those
who only casually met him to be proud or even
haughty. But under this outer crust, which soon
dropped away in friendly intercourse, there lay a
friendly and helpful nature. Indomitable in his
power of work, restless in his eager energy in the
pursuit of his favourite science, full of sympathies
for realms of knowledge outside of his own domain,
wielding wide influence from his wealth and social
position, he did what no other man of his time
could do so well for the advance of science in
England. And his death at the ripe age of seventy-
nine left a blank in that country which has never
since been quite filled.
Sedgwick was in many respects a contrast to
Murchison. His powerful frame reminded one of
the race of dalesmen from which he sprang. His
eagle eyes seemed as if they must instantly pierce
into the very heart of the stifFest geological problem.
In his prime, he always made straight for the roughest
2 E
434 Personal characteristics of Sedgwick
ground, the steepest slopes, or the highest summits,
and his bodily strength bore him bravely through
incredible exertion. Unfortunately his health, always
uncertain, would react on his spirits, and times of
depression and lethargy would come to interrupt
and retard his work, whether with hammer or pen.
But even his gloomiest fits he could turn into
merriment, and he would laugh at them and at him-
self, as he described his condition to some friend.
His gaiety of spirit made him the centre and life
of every company of which he formed part. His
frank manliness, his kindliness of heart, his trans-
parent childlike simplicity, his unwearied helpfulness
and his gentle tenderness, combined to form a char-
acter altogether apart. He was admired for his
intellectual grasp, his versatility, and his eloquence,
and he was beloved, almost worshipped, for the
overflowing goodness of his character.
When in the early part of this century, one
discovery after another was made which showed
that Werner's so-called primitive rocks reappeared
among his Transition and Floetz formations, a doubt
began to arise whether there were any primitive
rocks at all. 1 We have traced how Murchison and
Sedgwick cleared up the confusion of the Transition
series and created the Devonian, Silurian and Cam-
brian systems. In W T ales certain schists had been
detected by Sedgwick below his Cambrian rocks,
but they did not greatly interest him, and he never
1 Thus D'Aubuisson wrote in 1819 "Geology no longer possesses
a single rock essentially primitive" (Traite de Geognosie, tome ii. p.
J97)-
William Edmond Logan 435
tried to make out their structure and history. After-
wards A. C. Ramsay (1814-1891) and his associates
claimed these schists as metamorphosed parts of the
Cambrian system. To this day their true position
has not been settled further than that they are known
to be pre-Cambrian.
The vast and varied series of rocks, which have
now been ascertained to underlie the oldest Cambrian
strata, have undergone much scrutiny during the last
half century, and their true nature and sequence are
beginning to be understood. The first memorable
onward step in this investigation was taken in
North America by William Edmond Logan (1798-
1875). Many years before his time, the existence
of ancient gneisses and schists had been recognised
both in the United States and in Canada. At the
very beginning of the century, the wide extent of
these rocks had been noted by W. Maclure, whose
general geological sketch-map of a large part of the
United States will be referred to on a later page. In
1824 and afterwards, Dr. J. J. Bigsby (1792-1881)
spent much time among these rocks to the north of
Lake Superior. Subsequently the gneisses of the
Adirondack Hills were described by Amos Eaton.
At the very beginning of his connection with the
Geological Survey of Canada in 1843, Logan con-
firmed the observation that the oldest fossiliferous
formations of North America lie unconformably on
a vast series of gneisses and other crystalline rocks >
to which he continued at first to apply the old term
Primary. By degrees, as he saw more evidence
of parallel structures in these masses, he thought
436 Alexander Murray, S terry Hunt
that they were probably altered sediments, and he
referred to them as Metamorphic. That portion of
the series which includes thick bands of limestone
he proposed to consider as a separate and overlying
group. In the course of years, working with his
associates Alexander Murray and T. Sterry Hunt, he
was able to show the enormous extent of these
primary rocks, covering as they do several hundred
thousand square miles of the North American con-
tinent, and stretching northwards to the borders of
the Arctic Ocean. He proposed for these most
ancient mineral masses the general appellation of
Laurentian, from their development among the
Laurentide mountains. Afterwards he thought it
possible to subdivide them into three separate
groups, which he designated Upper, Middle and
Lower. In the course of his progress, he came
upon a series of hard slates and conglomerates,
containing pebbles and boulders of the gneiss,
and evidently of more recent origin, yet nowhere,
so far as he could see, separable by an undoubted
unconformability. These rocks, being extensively
displayed along the northern shores of Lake Huron,
he named Huronian. He afterwards described a
second series of copper-bearing rocks lying uncon-
formably on the Huronian rocks of Lake Superior.
He thus recognised the existence of at least three
vast systems older than the oldest fossiliferous for-
mations. He may be said to have inaugurated the
detailed study of Pre-Cambrian rocks. Subsequent
investigation has shown the structure of the regions
which he explored to be even more complicated and
Logans services to Geology 437
difficult than he believed it to be, and various im-
portant modifications have been proposed in his work
and terminology by the able geologists of Canada
and the United States who have continued his
labours. But he will ever stand forward as one of
the pioneers of geology, who in the face of incredible
difficulties, first opened the way towards a compre-
hension of the oldest rocks of the crust of the
earth.
CHAPTER XIV
PROGRESS of Stratigraphical Geology continued. Influence of Charles
Darwin. Adoption of Zonal Stratigraphy of fossiliferous rocks.
Rise of Glacial Geology, Louis Agassiz. Development of Geo-
logical map-making in Europe and North America.
THE fundamental principles of Stratigraphy having
been well established before the middle of last cen-
tury, this branch of geological science has during
the last fifty years undergone a remarkable expansion
from four influences. Firstly, it has been profoundly
modified by the writings of Darwin ; secondly, it
has been greatly affected by the introduction of
zonal classification among the fossiliferous formations ;
thirdly, it has been augmented by the rise and extra-
ordinary development of Glacial Geology ; and lastly,
it has enormously gained by the multiplication of
detailed geological maps.
I. Charles Darwin (1809-1882) contributed several
valuable works to the literature of geology. But it is
not for these that I now cite his name. The two
geological chapters in his Origin of Species produced
the greatest revolution in geological thought which has
occurred in my time. Younger students, who are
familiar with the ideas there promulgated, can hardly
realise the effect of them on an older generation.
Influence of Darwin on Stratigraphy 439
They seem now so obvious and so well-established,
that it may be difficult to conceive a philosophical
science without them.
To most of the geologists of his day, Darwin's con-
tention for the imperfection of the geological record,
and his demonstration of it, came as a kind of surprise
and awakening. They had never realised that the
history revealed by the long succession of fossiliferous
formations, which they had imagined to be so full, was
in reality so fragmentary. And yet when Darwin
pointed out this fact to them, they were compelled,
sometimes rather reluctantly, to admit that he was
right. Some of them at once adopted the idea, as
Ramsay did, and carried it further into detail. 1
Until Darwin took up the question, the necessity
for vast periods of time, in order to explain the char-
acters of the geological record, was very inadequately
comprehended. Of course, in a general sense, the great
antiquity of the crust of the earth was everywhere
admitted. But no one before his day had perceived
how enormous must have been the periods required
for the deposition of even some thin continuous groups
of strata. He supplied a criterion by which, to some
degree, the relative duration of formations might per-
haps be apportioned. When he declared that the
intervals which elapsed between consecutive formations
may sometimes have been of far longer duration than
the formations themselves, contemporary geologists
could only smile incredulously in their bewilderment,
1 See the two Presidential Addresses to the Geological Society,
by A. C. Ramsay, Quart. Journ. Geol. Soc. vols. xix. (1863), xx.
(1864).
44 Zonal Classification in Stratigraphy
but in a few years Ramsay showed by a detailed exam-
ination of the distribution of fossils in the sedimentary
strata that Darwin's suggestion must be accepted as an
axiom in geological theory. Again, the great naturalist
surmised that, before the deposition of the oldest known
fossiliferous strata, there may have been antecedent
periods, collectively far longer than from the date of
these strata up to the present day, and that, during
these vast, yet quite unknown, periods, the world may
have swarmed with living creatures. But his contem-
poraries could only shrug their shoulders anew, and
wonder at the extravagant notions of a biologist. But
who nowadays is unwilling to grant the possibility, nay
probability, of Darwin's surmise ? Who can look upon
the earliest Cambrian fauna without the strongest con-
viction that life must have existed on this earth for
countless ages before that comparatively well-developed
fauna came into existence ? For this expansion of
our geological vision, and for the flood of light
which has been thrown upon geological history by
the theory of evolution, we stand mainly indebted
to Charles Darwin.
II. Although the value of organic remains as a
means of identifying strata had been amply proved
during the earlier half of last century, neither geologists
nor palaeontologists were then aware of the extent
to which this chronological and stratigraphical test
could be carried out in the practical classification of
fossiliferous formations. They were content with the
broad subdivisions, often to a large extent based on
variations of sedimentary material, into which they
arranged the geological record. Eventually, however,
Its application in Europe 441
it was shown by Oppel 1 and Quenstedt 2 that the
Jurassic series of Western Europe is not only capable
of subdivision into the lithological groups which
William Smith found to be distinguished by their
peculiar fossils, but that in these groups it was often
possible to trace a succession of horizons or zones,
each characterised by the presence of one or more
species of organic remains, which are either confined
to it or are more particularly conspicuous in it ; that
these zones can be followed over Germany, France
and England, and that, though the lithological character
of the strata may vary locally, the same sequence of
genera and species of fossils is on the whole maintained.
These observers found that the Ammonites are especi-
ally serviceable in the identification of such zones, on
account of their comparatively limited vertical range.
Thus in the Lias no fewer than seventeen zones have
been distinguished, each of which is known by the
name of its characteristic Ammonite, as the zone of
Psiloceras planorbe^ which lies at the bottom, and that
of Lytoceras jurense y which forms the top of the series.
The same principle of arrangement was afterwards
found to hold good for the Cretaceous formations,
and it has since been extended through the lower
Palaeozoic rocks down even to the bottom of the
Cambrian system. In the Silurian formations the
most useful fossils for zonal purposes have been
shown by Professor Lapworth to be the Graptolites.
The lowest known fossiliferous platform among the
rocks of the Old and New Worlds is that of the
l Die Juraformation Englands, Frankreichs und Deutschlands, 1856-58.
2 Der Jura, "1858.
44 2 Rise of Glacial Geology
O!ene/!us-zone, where this distinctive genus of trilobite
is found.
This extension of William Smith's doctrine of
" Strata identified by fossils " has greatly contributed
to the progress of stratigraphy, and has furnished a
fresh clue to the interpretation of the structure of dis-
tricts in which the fossiliferous rocks have been much
dislocated and plicated. The general succession of
zones appears to be always similar, even in widely
separated regions ; but the same zones are not every-
where present nor do the same genera and species
always range over the world, though where they do
reappear they are believed to keep the same relative
order of occurrence.
III. The rapid development of Glacial Geology forms
one of the most interesting chapters in the history
of modern science. It began within the memory of
men yet living, and many of the observers who have
most energetically contributed to its progress are still
actively at work. The literature devoted to glaciation
has grown into a huge bulk, and continues to increase
every year. Looking back to the beginning of the
investigation we may note that although, as has been
already alluded to (p. 314), Playfair, at the beginning
of last century, had pointed out the pre-eminent place
of glaciers as the agents of transport for large blocks of
stone, his acute observation seems to have passed out
of mind. 1 Venetz and Charpentier were the first to
take up anew this interesting department of geology,
to trace the dispersal of the crystalline rocks of the
Central Alps outward across the great Swiss plain
^Illustrations of the Huttonian Theory, p. 348. Ante p. 314.
J. L. R. Agassiz, his early career 443
to the flanks of the Jura mountains, 1 and thus to
demonstrate the former great extension of the Swiss
glaciers. It was reserved, however, for Agassiz to
perceive the wide significance of the facts observed,
and to start the investigations that culminated in the
recognition of an Ice Age which involved the whole
of the northern part of our hemisphere, and in the
voluminous literature which has recorded the rapid
progress of this department of geology.
Jean Louis Rodolphe Agassiz (1807-1873) was born
in Switzerland, and rose to distinction by his scien-
tific work in Europe, but he went to the United
States when he was still only forty-two years of age,
and spent the last twenty-seven years of his life as
an energetic and successful leader of science in his
adopted home. His fame is thus both European
and American, and the geologists of New England,
not less than those of Switzerland, may claim him as
one of their most distinguished worthies.
We must pass over the brilliant researches into the
history of fossil fishes, which placed the name of
Agassiz high among the palaeontologists of Europe
when he was still a young man. What we are more
particularly concerned with here is the share he had
in founding the modern school of glacial geology. As
far back as the summer of 1836 he was induced to
visit the glaciers of the Diablerets and Chamounix,
and the great moraines of the Rhone valley, under
the guidance of Charpentier, whose views as to the
former extension of the ice he was disposed to doubt
l Schzveizer. Gesell. VerhandL 1834, p. 23 ; Ann. des Mines, viii.
(1835) P- 2I 9 5 Leonhard und Bronn, Ne-ues Jahrb. 1837, p. 472.
444 Agassiz
and reject. But the result of this tour was to convince
him that the phenomena were even more stupendous
than Charpentier had asserted. In spite of the claims
of his palaeontological and zoological undertakings,
Agassiz was so fascinated by the ice-problem of the
Alps that he must needs pursue the subject with all
the enthusiasm and industry of his character. He
took the earliest opportunity of again investigating the
evidence furnished by the slopes of the Jura moun-
tains, and became so firmly convinced of the truth
and wide importance of the conclusions at which he
had arrived that he determined to publish these to the
world. Accordingly in the summer of the following
year (1837), when only thirty-three years of age, he
took the opportunity, as President of the Helvetian
Society of Natural Science, to give an address in which
he struck, with the hand of a master, the keynote of all
his future research in glaciation. Tracing the distribu-
tion of the erratic blocks above the present level of the
glaciers, and far beyond their existing limits, he con-
nected these transported masses with the polished and
striated rock-surfaces which were known to extend
even to the summits of the southern slopes of the
Jura. He showed, from the nature of these smooth
surfaces, that they could not have been worn into their
characteristic forms by any current of water. The fine
striae, engraven on them as with a diamond-point, he
proved to be precisely similar to those now being
scratched on the rocky floors of the modern glaciers,
and he inferred that the polished and striated rocks
of the Jura, even though now many leagues from
the nearest glacier, must have acquired their peculiar
His glacial studies in Switzerland 445
surface from the action of ice moving over them, as
modern glaciers slide upon their beds. He was thus
led to conclude that the Alpine ice, now restricted to
the higher valleys, once extended into the central plain,
crossed it, and even mounted to the southern summits
of the Jura chain.
Before Agassiz took up the question, there were two
prevalent opinions regarding the transport of the
erratics. One of these called in the action of power-
ful floods of water, the other invoked the assistance
of floating ice. Agassiz combated these views with
great skill. His reasoning ought to have convinced
his contemporaries that his explanation was the true
one. But the conclusions at which he arrived seemed
to most men of the day extravagant and incredible.
Even a cautious thinker like Lyell saw less difficulty
in sinking the whole of Central Europe under the sea,
and covering the waters with floating icebergs, than in
conceiving that the Swiss glaciers were once large
enough to reach to the Jura. Men shut their eyes
to the meaning of the unquestionable fact that, while
there was absolutely no evidence for a marine sub-
mergence, the former track of the glaciers could be
followed mile after mile, by the rocks they had scored
and the blocks they had dropped, all the way from
their present ends to the far-distant crests of the
Jura.
Agassiz felt that the question was connected with
large problems in geology. The former vast extension
of the Swiss glaciers could be no mere accidental or
local phenomenon, but must have resulted from some
general lowering of temperature. He coupled with
446 Agassiz
this deduction certain theoretical statements regarding-
former climates and faunas, which have not been sup-
ported by subsequent research.
The main conclusions which the Swiss naturalist
drew, so greatly interested him that he spent part of
five successive summers investigating the vestiges of
the old glaciers, and the operations of those of the
present time. He convinced himself that the great
extension of the ice was connected with the last great
geological changes on the surface of the globe, and with
the extinction of the large pachyderms, whose remains
are so abundant in Siberia. He believed that the
glaciers did not advance from the Alps into the plains,
but rather that ice once covered all the lower grounds,
and finally retreated into the mountains.
Having arrived at these conclusions from studies in
his native country, Agassiz was naturally desirous to
see how far his views could be tested or confirmed in
a region far removed from any existing glaciers.
Accordingly, in the year 1840, three years after his
address at Neufchatel, he had an opportunity of
visiting Britain, and took advantage of it to examine
a considerable part of Scotland, the north of England,
and the north, centre, west, and south-west of Ireland.
The results of this investigation were of remarkable
influence in the progress of glacial geology. Agassiz
demonstrated the identity of the phenomena in Britain
with those in Switzerland, and claimed " that not
only glaciers once existed in the British Islands,
but that large sheets (nappes) of ice covered all the
surface." l
1 Proc. Geol. Soc. vol. iii. (1840) p. 331.
Impetus given by him to Glacial Research 447
These and the subsequent researches and glacial
monographs of the great Swiss naturalist started the
study of ancient glaciation. At first his conclusions
had been regarded as rank heresy by the older and
more conservative geologists of the day. Von Buch
" could hardly contain his indignation, mingled with
contempt, for what seemed to him the view of a youth-
ful and inexperienced observer." x A. von Humboldt
also threw cold water upon the ardour of his young
friend. But by degrees the opposition waned, and
Agassiz had the satisfaction of seeing his most
doughty opponents come over one by one to his
side. Nowhere were his triumphs more signal than
in the British Isles. Buckland (1784-1856), who
enjoyed the advantage of being shown the evidence
in Switzerland by Agassiz himself, was the first con-
vert of distinction. He signalised his change of
opinion by publishing a paper to prove the former
presence of glaciers in Scotland and the north of
England, followed by another communication on " the
glacio-diluvial phenomena in Snowdonia and the adja-
cent parts of North Wales." 2 Lyell about the same
time was won over by Buckland, and likewise hastened
to announce his acceptance of the new views by pub-
lishing a paper on the former existence of glaciers in
Forfarshire. 3 A few years later James David Forbes
(1808-1868) gave an account of glaciers that nestled
1 Louis Agassiz, his Life and Correspondence, by E. Gary Agassiz,.
vol. i. p. 264.
' 2 Proc. Geol. Soc. vol. iii. (1841) pp. 332, 345, 579.
*Proc. Geol. Soc. vol. iii. (1841) p. 337.
448 J* D. Forbes; C. Maclaren; R. Chambers
among the Cuillin Hills of Skye, 1 and Charles
Maclaren found glacier moraines in the valleys of
Argyleshire. 2
At first, however, the existence of former glaciers in
the valleys of Britain was the main conclusion sought
to be established. British geologists, and indeed geolo-
gists generally, were still for many years unwilling to
admit that not only the mountain-valleys, but even the
lowlands of the northern hemisphere were, at a late
geological period, buried under sheets of land-ice.
They preferred to call in the action of floating ice,
without perceiving that in so doing they involved
themselves in far more serious physical difficulties
than those which they sought to avoid.
Important service towards the ultimate acceptance
of Agassiz's enlarged conception of the glaciation of
Europe was rendered by Robert Chambers (1802-
1871), in a series of suggestive papers on the superficial
deposits and striated rocks of Scotland, 3 and in another
contribution (Tracings of the North of Europe > 1851),
l Edin. New Phil. Journ. xl. (1845) p. 76. To Forbes glacial
geology stands deeply indebted. He contributed to the Edinburgh
New Philosophical Journal an important series of letters from 1842
to 1851. He was likewise the author of excellent papers in
the Proceedings and Transactions of the Royal Society of Edinburgh,
of three memorable contributions on the viscous theory of glacier-
motion in the Philosophical Transactions of the Royal Society of
London (1846) and of two now classic works, his Travels through the
Alps of Savoy, etc. (1843) and Norway and its Glaciers (1853).
*Edin. New Phil. Journ. xl. (1845) P- I2 5 xlv "- ( l8 49) P- I0 ^ ;
xlix. (1850) p. 334 ; Ib. new series i. (1855) p. 189.
3 Edin. New Phil. Journ. liv. (1852) p. 229 ; Ibid, new ser. i. (1855)
p. 103 ; ii. p. 184.
Earliest Geological Maps 449
in which he detailed the results of a journey made by
him to the north of Norway. In later years, by the
labours of T. F. Jamieson, A. C. Ramsay and others,
the extension of land-ice over the British Isles, and the
direction taken by the chief ice-sheets in their move-
ment across the country, came to be regarded as well-
established facts in Post-Tertiary geology.
The literature of this branch of the science is now
extensive and is increasing every year at a rapid rate.
In Europe and in North America the glaciation of
almost every region has been studied in great detail.
A vast quantity of important fact has been accumu-
lated to fill in the broad outlines traced by Agassiz,
but his teaching in all its essential parts has long
been generally accepted, and his name is now enshrined
as the main founder of glacial geology.
IV. Geological Maps. As the progress of strati-
graphical geology has been so largely aided by the
production of maps on which the distribution and
order of succession of the various rocks can be made
visible to the eye, it may not be inappropriate to
close a sketch of the foundation and development
of this branch of the science with a short account
of the first beginnings and early history of geological
cartography. It will be remembered that, as far back
as the year 1683, Martin Lister suggested that it
would be possible to show the distribution of the
soils, rocks and minerals of a country upon the
basis of an ordinary topographical map. He brought
before the Royal Society, and published in the Philo-
sophical Transactions, what was called " An ingenious
proposal for a new sort of Maps of Country, together
2 F
450 Martin Lister s project
with tables of sands and clays, such chiefly as are
found in the north parts of England, drawn up about
ten years since, and delivered to the Royal Society,
March 12, 1683, by the Learned Martin Lister,
M.D." 1 In this " soile or mineral map" it was
proposed that " the soile might either be coloured
or otherwise distinguished by variety of lines or
etchings, but the great care must be, very exactly
to note upon the map where such and such soiles
are bounded. " By the term c soil ' Lister meant not
only the vegetable soil at the surface, but the sub-
soil and rocks underneath. "For I am of opinion,"
he remarks, " such upper soiles, if natural, infallibly
produce such under minerals, and, for the most part,
in such order." <c If the limits of each soile appeared
upon a map, something more might be comprehended
from the whole and from every part, than I can
possibly foresee ; but I leave this to the industry
of future times."
Lister's proposal, however, does not seem to have
been followed by any practical result for some two
generations. In the year 1743, there was published in
England what is believed to be the earliest specimen
of a geological map, under the title of "A new Philo-
sophico-Chorographical Chart of East Kent, invented
and delineated by Christopher Packe, M.D." The
author sent a letter on the subject to the Royal
Society, and accompanied his Chart with a tract
wherein he states that his undertaking c ' is no dream
or devise, the offspring of a sportive imagination,
conceived and produced for want of something else
iL Trans, vol. xiv. p. 739.
Christopher Packers map of Kent 45 1
to do, at my leisure in my study, but it is a real
scheme, taken upon the spot with patience and dili-
gence, by frequent or rather continual observations,
in the course of my journeys of business through
almost every the minutest parcel of the country :
digested at home with much consideration, and com-
posed with as much accuracy as the observer was
capable of." The Chart, which he indignantly refused
to call a map, is on the scale of rather more than an
inch and a half to a mile, and comprises the country
around Canterbury. It shows the positions of the
valleys and distinguishes the hills by the nature of
their component materials, such as chalk, " stone-
hills" (Lower Greensand) and " clay-hills," lying over
the plain of the Weald. As many parts of the valley
system are now dry, Packe inferred that they were
not hollowed by streams, but by the retiring waters
of the Deluge and have remained without change
ever since. 1
The mineralogical maps of Guettard have already
been noticed (p. no). The earliest of these was
presented to the Academy of Sciences of Paris in
1746, and the series was continued by the same
industrious observer until he handed over the further
prosecution of the task to his successor Mounet.
The early map of Fuchsel (1762) has been referred
to in Chapter VII. (p. 198). The first map in which
the various geological formations were represented by
washes of colour appears to have been one by G.
Glaser published at Leipzig in the year 1775 in his
Versuch einer mineralogischen Beschreibung der gefursteten
1 See a paper by Fitton in Phil. Mag. vol. i. (1832) p. 447.
45 2 Eany maps in Germany and France
Graftschaft Henneberg, Chursachsischen Antheih. Three
years later a more important map, also in colour, was
issued at Leipzig in 1778 by J. F. W. Charpentier,
Professor in the Mining Academy of Freiberg, to
accompany his excellent quarto monograph on the
Mineralogische Geographic der Chursachsischen Lande.
Eight tints are used to discriminate granite, gneiss,
schist, limestone, gypsum, sandstone, river-sand, clay
and loam ; and there are also symbols to point out
the localities for basalt, serpentine, etc.
Palassou, in his Essai sur la MMralogie des Monts
Pyrenees, Paris, 1781, gave a series of maps with
engraved lines and signs, and also a route-map of
the part of France between Paris and the Mediter-
ranean, with the general mineralogical characters of
each line of route indicated by strips of colour. He
thus distinguished by a green line the granite rocks,
by a yellow line the u schists," and by a red line the
calcareous rocks. He also indicated the presence of
these various formations by different symbols, among
which was one for extinct volcanoes, that figures in the
Clermont region and also to the west of Montpellier.
William Smith's map, the history of which has
been referred to in Chapter XII. appeared in the year
.1815 with the following title "A Geological Map
of England and Wales, with Part of Scotland ; exhibit-
ing the Collieries, Mines, and Canals, the Marshes
and Fen Lands originally overflowed by the Sea ;
and the Varieties of Soil, according to the Variations
of the Substrata ; illustrated by the most descriptive
Names of Places, and of Local Districts ; showing
also the Rivers, Sites of Parks, and Principal Seats of
Maps of Smith and Greenough 45 3
the Nobility and Gentry ; and the opposite coast of
France. By William Smith, Mineral Surveyor." The
map consists of fifteen sheets on the scale of five miles
to an inch ( 33 ^soo)? and measures 8 feet 9 inches in
height by 6 feet 2 inches in width. It was accompanied
with a quarto memoir or explanation of 50 pages.
While Smith's map was in preparation another large
geological map of England and Wales was indepen-
dently constructed by George Bellas Greenough (1778-
1855), an able geologist and a caustic critic of his
contemporaries and predecessors. 1 This map was
published in 1819. In the memoir which accompanied
it the author states that though he knew, as early
as 1804, that Smith had begun a similar work, he
had been led to believe that the design was abandoned.
Accordingly he undertook the task in 1808, and
having been encouraged by the Geological Society, of
which he was President, to complete it on the scale
of eleven miles to an inch ( 696 1 960 ) ? he proceeded
with it, and the map as prepared by him had been
more than a year in the hands of the engraver when
Smith's map appeared in 1815. Greenough's is a
better piece of engraving, and in some respects is
more detailed, especially as regards the formations
older than the Coal. It shows how much information
as to English stratigraphy had become available, partly
1 His qualities are characteristically exhibited in the volume which
he published in 1819 entitled A Critical Examination of the First
Principles of Geology. Every school of writers comes in there for its
share of his pungent criticism, and he shows his wide acquaintance
with the literature of the science. He was one of the founders
of the Geological Society, and as long as he lived was one of its
most respected and influential members.
454 Macculloch" s Map of Scotland
no doubt through Smith's labours, before 1815.
Greenough's map was published and taken over by
the Geological Society, whose property it became.
The second edition, much revised and improved, was
published in 1839 and since then the map has from
time to time been brought up to date, and is still on
sale. But in its present form it differs much from
its author's original version. The appearance of this
map under the auspices of the Geological Society no
doubt affected the sale of Smith's, which does not
appear to have reached a second edition, though a
much reduced version of it was published in 1820.
In the list of the cartographical achievements of
the earlier decades of last century, a place must be
found for the remarkable maps and descriptions of
Scotland for which geology is indebted to the genius
and strenuous labour of John Macculloch. As already
stated (p. 261), his account of the structure of the
Western Isles, and the excellent maps and sections
which accompanied it, had a powerful influence in
promoting the progress of the study of igneous rocks,
and have long since taken their place as geological
classics. The same indefatigable observer, after years
of toil prepared a geological map of the whole
of Scotland, on the scale of four miles to an inch
^.^i-^.) a most remarkable achievement to have
been accomplished unaided by one observer, at a
time when means of locomotion were as yet unde-
veloped over wide tracts of the country. 1
1 A Description of the Western Isles of Scotland, 1819 ; A Geological
Map of Scotland, 1840 ; and Memoirs to His Majesty's Treasury respect-
ing the Geological Map of Scotland, by J. Macculloch, 1836,
Griffith's Map of Ireland 455
What Macculloch did for Scotland was done even
more efficiently for Ireland by Richard Griffith (1784-
1878), who, born in Dublin in 1784, devoted his long
and active life to carrying out surveys and other
investigations for the development of the resources of
his native country. In the course of his innumerable
journeys into all parts of the island, he accumulated a
large body of notes regarding its geology, and from
time to time inserted the data upon a map of Ireland.
This map was at last ordered by the Government to
be reconstructed and engraved on the scale of four
miles to an inch, and it was published in the spring of
1839. He continued to make improvements on it as
his knowledge of the geology of the country increased,
and to embody these in successive editions. If regard
be had to its large scale and to the amount of detail
expressed upon it, this work must be admitted to be
the most remarkable map of a whole country ever
constructed by a single individual. Its singular accuracy
and breadth of treatment have been amply proved by
the subsequent work of the Geological Survey.
Allusion has already been made to some of the
pioneer geological cartographers by whom the distribu-
tion of the rocks on the European continent was first
delineated. The early map of Germany by Von Buch
was noticed in Chapter VIII. (p. 251). In France the
mineralogical charts of Guettard and Palassou were
followed in 1 8 1 1 by the fuller geological map of the
Paris basin by Cuvier and Brongniart (p. 366), and in
1813 by that of Omalius d'Halloy (p. 377), embracing
a large tract of the north of France. The first general
geological map of the whole of France was prepared
456 Institution of Geological Surveys
as a national undertaking. In the year 1820 a copy of
Greenough's map of England and Wales having been
sent to the Ecole des Mines at Paris, the desire arose
to provide France with a similar compendium of its
geology. Accordingly two engineers of the Mines
Department, Elie de Beaumont (1798-1874) and
Dufrenoy, were, in 1822, sent to England, where they
spent six months studying the principles on which the
English map had been constructed, and other subjects
connected with the project. The map of France, begun
in 1825 and completed in 1840, consisted of six sheets
on the scale of about eight miles to an inch. This great
work, so rapidly carried out, remains as a remarkable
monument of the genius of the two geologists under
whose supervision it was constructed.
The most important impulse towards the complete
and methodical investigation of the geology of wide
regions of the earth's surface has been given by the
institution of State surveys for the express purpose of
constructing geological maps of entire countries, com-
bined with the determination of the character and
distribution of useful minerals, and with the formation
of large collections of rocks, minerals and fossils. Great
Britain led the way in this line of national effort, by
inaugurating in 1835, at tne instigation and under the
personal supervision of Henry Thomas de la Beche, a
Geological Survey of the British Isles, together with
a School of Mines and a Mining Record Office. The
objects of the Geological Survey were to ascertain and
depict on maps, as accurately and in as much detail as
possible, on the scale of one inch to an English mile
(or 6 33eo)> the geological structure of the country,
Geological Survey of Great Britain 457
together with the position and distribution of the
useful minerals; to prepare horizontal sections on a
scale of six inches to a mile ( 10 iUo)> showing the true
form of the surface and the ascertained or inferred
arrangement of the rocks underneath ; to publish
various memoirs and monographs in which the geology,
palaeontology, useful minerals and mineral industries
of the country should be fully described, and to form
a museum in which the rocks, minerals and fossils of
the British Isles should be amply represented by collec-
tions of specimens. The first maps issued by the
English Survey at once attracted notice as the largest
and most detailed maps that had yet appeared of any
part of the surface of the earth. De la Beche with
much sagacity and energy secured an able staff of
professors for his School of Mines, who did much
to stimulate the study of geology, mineralogy, palaeon-
tology, and natural history. Among these men were
Andrew C. Ramsay (1814-1891), Edward Forbes
(1815-1854), Warington Smyth (1817-1890), Lyon
Playfair (1818-1898), and John Percy (1817-1889).
De la Beche was succeeded in 1855 by Murchison,
under whom the staff of the Survey was much aug-
mented. The example set by the mother country has
been followed among the Colonies and Dependencies
of Britain, nearly all of which now have their inde-
pendent geological surveys. Most civilized countries
have also adopted similar organisations, so that now
detailed geological maps have been published for a
large part of Europe and North America. Even
Japan, in adopting the methods of the West, has not
omitted to include among them well-equipped geological
45 8 Early American Surveys
and seismological surveys. By the detailed style of
mapping now in general use the geological structure
of the earth is becoming every year more accurately
known. International co-operation has likewise been
called into requisition. And we are now in possession
of a geological map of the greater part of the European
continent, prepared mainly by the collaboration of the
national surveys of the different countries, under the
auspices of the International Geological Congress.
While geology, as shown by the production of Maps
and Memoirs, has made such steady progress in the
Old World, its advance has been in many respects
even more rapid and striking in the New. When we
look back upon the history of the science on the other
side of the Atlantic the first name that prominently
comes before us is that of William Maclure (1763-
1 840), who has been called the " Father of American
Geology." He was born at Ayr in Scotland, and after
acquiring a fortune in business in London, he went
in 1796 to the United States and finally settled there.
Having developed a taste for geology in Europe, he
was soon attracted by the comparative simplicity and
the imposing scale of the geological structure of his
adopted country, and in the course of some years
made many journeys across the Eastern States. He
recorded on a map his observations of the distribution
of the rocks, and in 1809 made a communication on the
subject to the American Philosophical Society at Phila-
delphia. In 1817, having extended his knowledge
during the intervening eight years, he presented his
map to that Society, and it was then published. This
map is of special interest, as the first sketch of the
Maclure, Eaton 459
geological structure of a large part of the United States.
It is on a small scale only 120 miles to an inch
(7603200) b ut it gi yes a broad delineation of the
general distribution of the larger formations. Maclure
was an open-minded adherent of the Freiberg system
of classification, for he frankly states that " although
subject to all the errors inseparable from systems
founded upon a speculative theory of origin, the
system of Werner is still the best and most compre-
hensive that has yet been formed."
The area depicted on this map extends from the
Canadian frontier to the Gulf of Mexico and from the
Atlantic Coast westward to about the 94th meridian.
The formations represented by colour are " Primitive
Rock, Transition Rock, Secondary Rock, Old Red
Sandstone, Alluvial Rock," and a green line is traced
from the north-east of New York State southwards
into Tennessee, " to the westward of which has been
found the greatest part of the salt and gypsum."
Among the errors of this sketch-map, hardly avoid-
able at the time, is the inclusion of various important
members of the Tertiary series among the alluvial
deposits. Further, among the Secondary formations
there is classed the horizontal westward extension of
the same rocks which, where highly inclined further
east, were regarded as Transition. But even with
these mistakes, the map must be admitted to be a
meritorious first outline of the geology of a vast
extent of territory.
In the year 1828 Amos Eaton (1776-1842) gave a
fuller synopsis than Maclure had done of the rocks of
North America, but misplaced some of the subdivisions.
460 Early geological maps of United States
G. W. Featherstonhaugh (1780-1866), who was ap-
pointed " United States Geologist," was employed in
making various surveys for the Government, and
collected a large amount of material towards the
construction of a better geological map of the whole
country. Born in France and well acquainted with
the rocks of Europe, he was able to institute a closer
and more correct parallel between these rocks and
their American equivalents than had previously been
attempted. Another early pioneer in the geology of
the United States was Lardner Vanuxem (1792-1848)
whose work on the geological survey of the State of
New York deserves special recognition. As one of
his important services he corrected the error of taking
an inclined position as any reliable indication of the
relative age of rocks, and insisted on the paramount
importance of identifying strata by the organic remains
contained in them. Following this principle, he was
able to declare that the Transition rocks of Ohio,
Kentucky and Tennessee were shown by their fossils
to be of the same age as those at Trenton Falls in
New York, and all of them equivalents of some of the
Transition rocks of Europe wherein the same fossils
had been found.
Later than these early leaders came the group of
distinguished men who, by their researches and surveys
in Pennsylvania, not only added a series of admirable
maps to geological literature, but enriched the science
with suggestive memoirs on mountain structure
William Barton Rogers (1804-1882), Henry Darwin
Rogers (1808-1866), and J. P. Lesley (1819-1903).
Most of the other States of the American Union have
Geological Surveys in United States 461
also instituted State Geological Surveys, and have pro-
duced excellent maps and descriptive memoirs, besides
amassing valuable collections of the minerals, rocks
and fossils of their respective domains. The central
government organised various surveys of the western
territories, which did admirable work of a pioneering
and prospective kind under such leaders as J. D. Powell
(1834-1902), J. S. Newberry (1822-1892), Clarence
King (1842-1898) and F. V. Hayden (1829-1887).
When it was found in 1879 tnat some of these explora-
tions were traversing the same ground, a consolidation
of the whole geological effort was made, and the Geo-
logical Survey of the United States was established.
The magnitude and excellence of the work already
accomplished by this organisation place it in the fore-
front of all national geological enterprises.
CHAPTER XV
THE Rise of Petrographical Geology William Nicol, Henry
Clifton Sorby. Conclusion.
I TURN now to the Petrographical department of
geological inquiry, as exhibiting the last great forward
stride which the science has taken. We have seen
how greatly geology and mineralogy were indebted to
Werner for his careful and precise definitions. The
impulse which he gave to the study of Petrography
continued to show its effects long after his time, more
particularly in Germany. Methods of examination were
improved, chemical analysis was more resorted to, and
the rocks of the earth's crust, so far as related to their
ultimate chemical constitution, were fairly well known
and classified. Their internal structure, however, was
very imperfectly understood. Where they were coarsely
crystalline, their component minerals might be readily
determined ; but where they became fine-grained, little
more could be said about the nature and association
of their constituents than might be painfully deciphered
with the help of a hand-lens, or could be inferred from
the results of chemical analysis. Hence though not
actually at a standstill, petrography continued to make
but slow progress. In some countries indeed, notably
IV. Nicolinvents a new petrological method 46 3
in Britain, it was almost entirely neglected in favour
of the superior attractions of fossils and stratigraphy.
But at last there came a time of awakening and rapid
advance.
In order to trace the history of this petrographical
resuscitation, we must in imagination transport our-
selves to the workshop of an ingenious and inventive
mechanician, William Nicol, who was a lecturer on
Natural Philosophy at Edinburgh in the early part of
last century. Among his inventions was the famous
prism of Iceland spar that bears his name. 1 Every
petrographer will acknowledge how indispensable this
little piece of apparatus is in his microscopic investi-
gations. He may not be aware, however, that it was
the same skilful hands that devised the process of
making thin slices of minerals and rocks, whereby
the microscopic examination of these substances has
become possible.
In the course of his experiments, Nicol hit upon
the plan of cutting sections of fossil wood, so as to
reveal its minutest vegetable structures. He took a
slice from the specimen to be studied, ground it
perfectly fiat, polished it, and cemented it by means
of Canada balsam to a piece of plate-glass. The
exposed surface of the slice was then ground down,
until the piece of stone was reduced to a thin pellicle
adhering to the glass, and the requisite degree of
transparency was obtained. Nicol himself prepared a
large number of slices of fossil and recent woods.
Many of these were described by Henry Witham in his
1 See Nicol's original account of his prism in Edln. New PhiL Journ.
vol. vi. (1829), p. 83.
464 W. Nicol's services to Petrography
Observations on Fossil Vegetables (1831), to which Nicol
supplied the first published account of his process.
Here then geologists were provided with a method
of investigating the minutest structures of rocks and
minerals. As it was now made possible to subject
any part of the earth's crust to investigation with the
microscope, it might have been thought that those
who devoted themselves to the study of that crust,
especially those who were more particularly interested
in the structure, composition and history of rocks,
would have hastened to avail themselves of the new
facilities for research thus offered to them.
It must be confessed, I am afraid, that geologists are
about as difficult to move as their own erratic blocks.
They took no notice of the possibilities put in their
way by William Nicol. And so for a quarter of a
century the matter went to sleep. When Nicol
died, his instruments and preparations passed into the
hands of the late Mr. Alexander Bryson of Edinburgh
who, having considerable dexterity as a manipulator,
and being much interested in the process, made many
additions to the collections which he had acquired.
In particular, he made numerous thin slices of
minerals and rocks for the purpose of exhibiting the
cavities containing fluid, which had been described
long before by Brewster 1 and by William Nicol. 2 In
my boyhood I had frequent opportunities of seeing
these and the other specimens in Mr. Bryson's
cabinet, as well as the fine series of fossil woods
sliced so long before by Nicol.
1 Trans. Roy. Soc. Edin. vol. x. (1824), p. I.
2 Edin. New. Phil. Jour. vol. v. (1828), p. 94.
H, C. Sorby 465
At last Mr. Henry Clifton Sorby came to Edin-
burgh, and had an opportunity of looking over the
Bryson collection. He was particularly struck with
the series of slices illustrating " fluid-cavities," and at
once saw that the subject was one of which the
further prosecution could not fail to " lead to
important conclusions in geological theory." 1 He
soon began to put the method of preparing thin
slices into practice, made sections of mica-schist, 2
and found so much that was new and important,
with a promise of such a further rich harvest of
results, that he threw his whole energy into the
investigation for several years, and produced at last
in 1858 the well-known memoir, On the Micro-
scopical Structure of Crystals^ which marks one of
the most prominent epochs of modern geology. I
have always felt a peculiar satisfaction in the re-
flection that though the work of William Nicol
was never adequately recognised in his lifetime,
nor for many years afterwards, it was his thin
slices, prepared by his own hands, that eventually
started Mr. Sorby on his successful and distinguished
career, and thus opened out a new and vast field for
petrographical investigation.
It is not necessary here to recapitulate the achieve-
ments which have placed Mr. Sorby's name at the
head of modern petrographers. He, for the first
time, showed how, by means of the microscope, it
was possible to discover the minute structure and
1 Quart. Journ. Geol. Soc. vol. xiv. (1858), p. 454.
2 Brit. Assoc. Reports, 1856, sections, p. 78.
3 Quart. Journ. Geol. Soc. vol. xiv. (1858), p. 453.
2 G
466 H. C. Sorby
composition of rocks, and to learn much regarding
their mode of origin. He took us, as it were,
into the depths of a volcanic focus, and revealed
the manner in which lavas acquire their characters.
He carried us still deeper into the terrestrial crust,
and laid open the secrets of those profound abysses
in which granitic rocks have been prepared. His
methods were so simple, and his deductions so start-
ling, that they did not instantly carry conviction to
the minds of geologists, more particularly to those of
his own countrymen. The reproach that it was
impossible to look at a mountain through a micro-
scope was brought forward in opposition to the new
departure which he advocated. Well did he reply
by anticipation to this objection. " Some geologists,
only accustomed to examine large masses in the
field, may perhaps be disposed to question the
value of the facts I have described, and to think
the objects so minute as to be quite beneath their
notice, and that all attempts at accurate calculations
from such small data are quite inadmissible. What
other science, however, has prospered by adopting
such a creed ? What physiologist would think of
ignoring all the invaluable discoveries that have been
made in his science with the microscope, merely
because the objects are minute ? . . . With such
striking examples before us, shall we physical geo-
logists maintain that only rough and imperfect
methods of research are applicable to our own
science ? Against such an opinion I certainly must
protest ; and I argue that there is no necessary
connection between the size of an object and the
Zirkel, Rosenbusch, Fouquk, Lkvy 467
value of a fact, and that, though the objects I
have described are minute, the conclusions to be
derived from the facts are great." 1
Professor Zirkel was the first geologist of note
who took up with zeal the method of investigation
so auspiciously inaugurated by Mr. Sorby. But some
five years had elapsed before he made his com-
munication on the subject to the Academy of Sciences
of Vienna. 2 From that date (1863) he devoted himself
with much zeal and success to the investigation, and
produced a series of papers and volumes which gave
a powerful impetus to the study of petrography.
This department of geology was indeed entirely re-
constituted. The most exact methods of optical
research were introduced into it by Professor Rosen-
busch. Professor Fouque, M. Michel Levy and others,
and the study of rocks once more competed with that
of fossils in attractiveness. We have only to look at
the voluminous literature which, within the last fifty
years has sprung up around the investigation of rocks,
to see how great a revolution has been effected by
the introduction of the microscope into the equipment
of the geologist. For this transformation we are, in
1 Quart. Journ. Geol. Soc. xiv. (1858), p. 497. See also Mr.
Sorby's Presidential Addresses to the Geological Society for 1879
and 1880.
2 Sitzungsber. Math. Naturzviss. vol. xlvii. ist part (1863), p. 226.
In this paper the author refers to previous occasional use of the micro-
scope for determining the mineralogical composition of rocks by Gustav
Rose, G. vom Rath, G. Jenzsch, M. Deiters and others. In England
the first geologist who published the results of his microscopical
examination of rocks was David Forbes, Popular Science Review (October
1867), vol. vi. p. 355.
468 Varied avocations of Geologists
the first instance, indebted to William Nicol and
Henry Clifton Sorby.
In the account which has been presented in this
volume of the work of some of the more notable men
who have created the science of geology, one or two
leading facts stand out prominently before us. In the
first place, even in the list of selected names which
we have considered, it is remarkable how varied have
been the ordinary avocations of these pioneers. The
majority have been men engaged in other pursuits,
who have devoted their leisure to the cultivation of
geological studies. Steno, Guettard, Pallas, Fachsel,
and many more were physicians, either led by their
medical training to interest themselves in natural
history, or not seldom, even from boyhood, so fond
of natural history as to choose medicine as their
profession because of its affinities with that branch of
science. Giraud-Soulavie and Michell were clergymen.
Murchison was a retired soldier. Alexandre Brongniart
was at first engaged in superintending the porcelain
manufactory of Sevres. Desmarest was a hard-worked
civil servant who snatched his intervals for geology
from the toils of incessant official occupation. William
Smith found time for his researches in the midst of all
the cares and anxieties of his profession as an engineer
and surveyor. Hutton, Hall, De Saussure, Von Buch,
Lyell and Darwin were men of means, who scorned
a life of slothful ease, and dedicated themselves and
their fortune to the study of the history of the earth.
Playfair and Cuvier were both teachers of other
branches of science, irresistibly drawn into the sphere
Slow growth of some parts of Geology 469
of geological inquiry and speculation. Of the whole
gallery of worthies that have passed before us, a
comparatively small proportion could be classed as in
the strictest sense professional geologists, such as
Werner, Sedgwick and Logan. Were we to step
outside of that gallery, and include the names of all
who have helped to lay the foundations of the science
we should find the proportion to be still less.
From the beginning of its career, geology has owed
its foundation and its advance to no select and privi-
leged class. It has been open to all who cared to
undergo the trials which its successful prosecution
demands. And what it has been in the past, it re-
mains to-day. No branch of natural knowledge lies
more invitingly open to every student who, loving the
fresh face of Nature, is willing to train his faculty of
observation in the field, and to discipline his mind by
the patient correlation of facts and the fearless dissec-
tion of theories. To such an inquirer no limit can be
set. He may be enabled to rebuild parts of the temple
of science, or to add new towers and pinnacles to its
superstructure. But even if he should never venture
into such ambitious undertakings, he will gain, in the
cultivation of geological pursuits, a solace and enjoy-
ment amid the cares of life, which will become to him
a source of the purest joy.
In the second place, the history of geological science
presents some conspicuous examples of the length of
time that may elapse before a fecund idea comes to
germinate and bear fruit. Consider for a moment
how many years passed before the stratigraphical con-
ceptions of Fttchsel, Lehmann, and Giraud-Soulavie
47 Tardy reception of new doctrines
took more definite shape in the detailed investigations
of Cuvier, Brongniart and Smith, and how many more
years were needed before the Secondary and Tertiary
formations were definitely arranged and subdivided as
they now stand in our tables. Remember too that
even after the principles of stratigraphy had been settled,
a quarter of a century had slipped away before they
were successfully applied to the Transition rocks, and
a still longer time before the system of zonal classifi-
cation was elaborated. Note how long the controversy
lasted over the origin of basalt, and how slowly
came the recognition of volcanic action as a normal
part of terrestrial energy, which has been in operation
from the earliest geological times and has left its
memorials even in the oldest known parts of the crust
of the earth. Mark also, in the history of physio-
graphical geology, that though the principles of this
branch of science were in large measure grasped by
Desmarest, De Saussure and Hutton in the eighteenth
century, their work was neglected and forgotten until
the whole subject has been revived and marvellously
extended in our own day. Again, let me recall how
slowly the key that now unlocks the innermost mysteries
of rock-structure was made use of. Five-and-twenty
years elapsed after William Nicol had shown how
stony substances could be investigated by means of the
microscope, before Mr. Sorby called the attention of
geologists to the enormous value of the method thus
put into their hands. Other five years had to pass
before the method began to be taken up in Germany,
and a still longer time before it came into general use
all over the world.
Tendency to specialisation 471
Such instances as these lead to two reflections. On
the one hand, they assure us of the permanent vitality
of truth. The seed may be long in showing signs of
life, but these signs come at last. On the other hand,
we are warned to be on the outlook for unrecognised
meanings and applications in the work of our own day
and in that of older date. We are taught the necessity
not only of keeping ourselves abreast of the progress
of science at the present time, but also of making our-
selves acquainted as far as we possibly can with the
labours of our predecessors. It is not enough to toil
in our little corner of the field. We must keep our-
selves in touch both with what is going on now, and
with what has been done during the past in that and
surrounding parts of the domain of science. Many a
time we may find that the results obtained by some
fellow-labourer, though they may have had but little
significance for him, flash a flood of light on what
we have been doing ourselves.
I am only too painfully aware how increasingly
difficult it is to find time for a careful study of the
work of our predecessors, and also to keep pace with
the ever-rising tide of modern geological literature.
The science itself has so widened, and the avenues
to publication have so prodigiously multiplied, that
one is almost driven in despair to become a specialist,
and confine one's reading to that portion of the litera-
ture which deals with one's own more particular branch
of the science. But this narrowing of the range of our
interests and acquirement has a markedly prejudicial
effect on the character of our work. There is but
slender consolation to be derived from the conviction,
472 Avoidance of Dogmatism
borne in upon us by ample and painful experience, that
in the case of geological literature, a large mass of the
writing of the present time is of little or no value for
any of the higher purposes of the science, and that it
may quite safely and profitably, both as regards time
and temper, be left unread. If geologists, and especi-
ally young geologists, could only be brought to realise
that the addition of another paper to the swollen flood
of our scientific literature involves a serious responsi-
bility ; that no man should publish what is not of real
consequence, and that his statements when published
should be as clear and condensed as he can make them,
what a blessed change would come over the faces of
their readers, and how greatly would they conduce
to the real advance of the science which they wish to
serve !
In the third and last place, it seems to me that one
important lesson to be learnt from a review of the
successive stages in the foundation and development
of geology is the absolute necessity of avoiding dog-
matism. Let us remember how often geological theory
has altered. The Catastrophists had it all their own
way until the Uniformitarians got the upper hand, only
to be in turn displaced by the Evolutionists. The
Wernerians were as certain of the origin and sequence
of rocks as if they had been present at the formation
of the earth's crust. Yet in a few years their notions
and overweening confidence became a laughing-stock.
From the very nature of its subject, as I have already
remarked, geology does not generally admit of the
mathematical demonstration of its conclusions. They
rest upon a balance of probabilities. But this balance
Conclusion 473
is liable to alteration, as facts accumulate or are better
understood. Hence what seems to be a well-established
deduction in one age may be seen to be more or
less erroneous in the next. Every year, however,
the data on which these inferences are based are more
thoroughly comprehended and more rigidly tested.
Geology now possesses a large and ever-growing
body of well-ascertained fact, which will be destroyed
by no discovery of the future, though it will doubt-
less be vastly augmented, while new light may be cast
on many parts of it now supposed to be thoroughly
known.
Each of us has it in his power to add to this
accumulation of knowledge. Careful and accurate
observation is always welcome, and may eventually
prove of signal importance. While availing ourselves
freely of the use of hypothesis as an aid in ascertaining
the connection and significance of facts, we must be
ever on our guard against premature speculation and
theory, clearly distinguishing between what is fact and
what may be our own gloss or interpretation of it.
Above all, let us preserve the modesty of the true
student, face to face with the mysteries of Nature
Proving all things and holding fast that which we
believe to be true, let us look back with gratitude
and pride to what has been achieved by our forerunners
in the race, and while we labour to emulate their
devotion, let us hold high the torch of science, and
pass it on bright and burning to those who shall
receive it from our hands.
INDEX.
Achelous, River, n, 35.
Aeolian Isles, 15, 20.
Agassiz, J. L. R., 443.
Agricola, 146, 147, 221.
"Alluvial Rocks" of Werner,
215.
Alps, glaciers of, in the history of
Glacial Geology, 443, 444.
America, progress of geology in
North, 458.
Ammonites, value of, in zonal
stratigraphy, 441.
Anaxagoras on earthquakes, 13.
Anaximenes on earthquakes, 13,
23-
Ancients, growth of naturalistic
views among, 7, 40 ; geological
conceptions of, 13, 28, 33 ;
liberty of speculation among,
40.
Animals and plants, Lamarck on
geological action of, 360.
Arabs, science among the, during
the Dark Ages, 42.
Archiac, Comte d', 108, 115,
181.
Arduino, G., 180, 195.
Aristotle on cosmical position of
the earth, 1 2 ; on earthquakes,
14 ; connected earthquakes
with volcanoes, 15 ; on origin
of minerals, 1 6 ; on rivers,
28 ; on former changes of
earth's surface, 34 ; on a
Universal Flood, 52.
Auvergne, volcanic geology of,
127-135, 141, 150, 158, 243,
246, 247 ; first topographical
map of, 154, 1 60, 169.
Avicenna on geological changes,
43-
Banks, Sir Joseph, 148, 391.
Barrande, J., 427.
Barrois, C., 271.
Basalt, controversy as to the origin
of, 135, 146, 149, 152, 1 60,
202, 221, 223, 242, 244,246,
327 ; supposed fossils in, 328.
Beringer, J. B., 102.
Bi g sb 7> J- JU435-
Black, Dr. Joseph, 285, 288, 316.
Black Sea, gain of land on shores
of, 29.
Blode, K. A., 263.
Boate's Ireland's Natural! His-
toric, 113.
Bohemia, Silurian fauna of, 427.
Bosphorus, gain of land in, 29.
Bottiger, C. A., 207.
Boue, Ami, 241, 247, 263, 421.
Boule, M., 271.
Breislak, S., 256, 402.
Brewster, D., 464.
Britain, Agassiz finds traces of
old glaciers in, 446 ; Buckland,
Lyell, and J. D. Forbes on
glaciers in, 447.
British Association for the Ad-
vancement of Science, 416.
Index
475
Brocchi, G., 51.
Brongniart, Alexandra, 365.
Bryson, A., 464.
Buckland, W., 413, 415, 447.
Buch, L. von, 242 ; lineage and
education, 245 ; his first geo-
logical work, 246 ; visits
Auvergne and abandons Wer-
nerian doctrine of the aqueous
origin of basalt, 246 ; his
account of Auvergne, 247 ; his
investigations in Scandinavia,
250 ; on recent uprise of
Scandinavia, 251 ; his geo-
logical map of Germany, 251 ;
his extensive travels, 252 ; his
personal appearance and habits,
253 ; opposes glacial geology,
447-
Buffalo, fossil, of Siberia, 179.
Buffon, G. L. Leclerc de, 88 ;
his Theory of the Earth, 89 ;
his Epoques de la Nature, 90,
140, 193 ; on "days" of
Creation, 91 ; on earliest
mountains and valleys, 92, 94 ;
on first beginnings of life, 92 ;
on origin of volcanoes, 93 ; on
age of the earth, 95, 96 ; on
denudation, 94, 95 ; on 'final
extinction of the earth by cold,
95 ; his literary skill, 96.
Burnet, Thomas, his Sacred Theory,
66, 90.
Cambrian system, established by
Sedgwick, 426 ; zonal strati-
graphy applied to, 441.
Cardano on fossil shells, 51.
Cartography, history of geological,
^ 77> I"; "5-
Cataclysmists or Catastrophists,
.: 374.472-
Catherine II., Empress of Russia,
,'7 6 :
Cesalpino on fossils, 53.
Chalk, fusion experiments on,
324 ; Cuvier and Brongniart
on the, 368 ; zonal stratigraphy
applied to, 441.
Chambers, R., 448.
Charpentier, T. von, 442, 443.
Charpentier, J. F. W., 452.
Childrey's Britannia Baconica, 113.
Chronology, geological, deter-
mined by fossils, 336.
Church, influence of the, on
geological speculation, 44, 64,
65> 73, 97-
Clerk, John, of Eldin, 285, 288,
316.
Condorcet on Guettard, 105,
107, 109, 137.
Conybeare and Phillips' Geology
of England, 108, 265, 399, 402.
Cook, voyages of Captain, 172,176.
Cosmogonies, origin of popular,
6, 65.
Cosmogonists, rise of the English
65 ; French Descartes, 79 ;
Leibnitz, 81 ; De Maillet, 84;
Buffon, 88.
Coupe, 344.
Cretaceous system, zonal strati-
graphy applied to, 441.
"Crystallite"ofSirJames Hall, 3 20.
Cunningham, R. Hay, 331.
Cuvier, on Scheuchzer's supposed
fossil man, I oo ; on Guettard,
107 ; on Desmarest, 142, 143,
145, 171 ; on De Saussure,
183, 308 ; on Werner, 207,
2 34 2 35> 2 37 ; on granite,
308 ; birth and early career
of, 363 ; becomes Professor of
Comparative Anatomy, 364 ;
on extinct vertebrates, 364 ;
his services to geology, 372,
401 ; his doctrine of catas-
trophes, 3/3 ; becomes Per-
petual Secretary of the Institute
of France, 376.
47 6
Index
D'Alembert and Desmarest, 143.
Danube, River, n, 32.
Darwin, C., influence of, on
modern geology, 438.
Daubeny, C., 109, 264.
Daubree, A., 325.
D'Aubuisson, J. F., 218, 231,
241, 391, 402, 434.
Davy, Sir Humphry, 413.
De la Beche, H. T., 265, 402,
411, 429, 456.
De Luc, J. A., 1 86, 296, 330.
De Verneuil, 6. P., 421.
Deiters, M., 467.
Deltas, Strabo on, 30.
Deluge of Noah, invoked to
account for fossil organic re-
mains, 46, 48, 51, 60, 61, 67,
98, 100, 102 ; local and
transitory nature of, recog-
nised, 52, 61, 71 ; invoked as
one of the great geological
events in the history of the
earth, 66, 67, 90.
Democritus on earthquakes, 13.
Denudation, Steno on, 57 ; Ray
on, 74, 126; Buffon on, 94,
95 ; Guettard on, 121, 139;
Desmarest on, 158, 161 ; De
Saussure on, 188 ; Hutton on,
311.
Descartes, R., cosmogony of, 79.
Deshayes, 404.
Desmarest, N., on Guettard, 107,
129, 132, 134; biographical
sketch of, 141 ; earliest geo-
logical essay of, 143 ; begins
the study of Basalt and the
volcanic region of Auvergne,
147 ; discovers the volcanic
origin of Basalt, 152, 223 ;
his demonstration of volcanic
history and denudation in
Auvergne, 160 ; his caution in
the publication of his obser-
vations, 153, 154, 155, 161 ;
his avoidance of controversy,.
162, 167, 169, 175 ; on
Physical Geography, 168 ;
sketch of, by Cuvier, 171 ; not
cited by L. von Buch, 247 ;
on Hutton, 295 ; his account
of geological progress in the
Paris Basin, 342, 343, 344.
Deucalion, flood of, 35 [mis-
printed " Decalion " in text].
Deville, Ch. Sainte-Claire, 108.
Devonian system, established by
Sedgwick and Murchison, 429.
Diderot and D'Alembert, En-
cyclopedic Methodlque of, 107,
168, 169.
Diluvialists, rise of the, 47.
Dolomieu, G. de, 174, 254, 260,
321.
Dover Strait, Desmarest on
cutting through of, 143.
Dufrenoy, P. A., 421, 456.
Dykes, 306 ; Hall's discovery of
origin of, 321 ; chilled margins
of, noted by him, 321.
Earth, varied history of the, 5 \
speculation as to early history
of, 59-61, 65,79, 8l > 8 4 8 9>
90 ; evidence for evolution of,
192.
Earthquakes, frequent in Medi-
terranean basin, 9 ; ancient
Greek explanations of, 13, 14;
Roman poets and philosophers
on, 1 6 ; nature of motion of,
discussed by Seneca, 23 ; ideas
of the ancients concerning,
27; Hooke on, 69, 71 ; Ray
on, 75 ; Descartes on, 80 ;
Leibnitz on, 82 ; Fuchsel on,
199 ; of Lisbon, 273, 275 ;
Michell's work on, 273 ;
modern research regarding,
279.
Eaton, A., 435, 459.
Index
477
Edinburgh in the latter half of
the eighteenth century, 285 ;
geological environment of, 287,
328 ; Royal Society of, 288,
316 ; convivial clubs of, 288 ;
School of Geology established
at, 325.
Egypt, geological changes ob-
served by the Ancients in, 28,
29>.33> 3".
Electricity invoked to account for
volcanoes and earthquakes, 257,
272.
Elephants, fossil, of Siberia, 178.
lilie de Beaumont, 417, 421,456.
Empedocles, a martyr to science,
27.
Encyclopedic Methodique, 107, 168,
169.
Eocene, 404.
Eratosthenes, 33.
Erzgebirge, geology of the, 196.
Ethiopia, 32.
Etna, 10, 17, 18, 19,25, 27,39,'
323-
Europe, International Geological
Map of, 458.
Evolution, as displayed in his-
tory of the earth, 5, 192 ;
of organic types, 84, 87 ;
Lamarck on, 350; opposition
of Cuvier to doctrines of, 374.
Evolutionists, 472.
Experiment in Geology, 1 90, 317.
Falloppio on Fossils, 52.
Faujas de St. Fond, 174, 255,327.
Featherstonhaugh, G. W., 421,
460.
Ferguson, Adam, 285.
" Figured " or " Formed " Stones,
45 6 9> 74 77> 8 3 97> IOO >
102, 119.
Fitton, W. H., 239, 328, 331,
394> 397-
Fleming, Rev. John, 330.
Floetz rocks, 196, 214, 218, 220,
222, 225, 231, 232,408, 409.
Flood. See Deluge.
Forbes, D., 467.
Forbes, E., 457.
Forbes, J. D., 447.
Forchhammer, G., 421.
" Formations " in Geology,
Fiichsel on, 199 ; Werner on,
212, 230, 370 ; Cuvier and
Brongniart on, 370.
Fortis, J. B. A., 174.
Fossil, original application of the
term, 215, 355 ; modern signi-
fication of, first assigned by
Lamarck, 355; and afterwards
universally adopted, 400.
Fossils, deductions of the
Ancients from, 33 ; arouse
attention in the Middle Ages,
43 ; controversy as to nature
of, 45, 48, 69, 97 ; regarded
as "sports of Nature," 45, 53,
74, 83, 98 ; claimed to be
really of organic origin, 5
51, 52, 54, 55, 60,61,67, 69,
83, 100, 1 1 8, 1 20, 200 ; early
illustrated works on, 67, 69,
76, 77, 98, 100, 102 ; include
extinct types, 84, 364 ; show
a succession of species, 84, 92,
l8 9 J 93 374; growth of
study of, 98, 100, 101, 102,
104, 117, 1 1 8, 119, 196, 200,
336, 338, 34 2 > 349>355> 3^4,
369, 3 86 > 396, 4 01 5 littoral
and pelagic, 344, 355, 358;
chronological significance of, at
last recognised, 406.
Fouque, F., 39, 271, 467.
Fracastoro on Fossils, 5 I .
France, rise of geology in, 104 ;
discovery of old volcanoes in,
127, 141, 146; leading position
in geology early acquired by,
140, 157.
47 8
Index
Freiberg, Mining School of, 204,
206, 208, 237, 239.
Fiichsel, G. C., 197-201, 233,
336, 4 01 -
Fusion, Hall's experiments on,
3I9 322.
Generelli, expositor of Moro, 65,
126.
Geognosy of Werner, 211.
Geological changes in the past,
views of the Ancients regard-
ing, 33-
Geological Maps, history of, 449.
Geological nomenclature, un-
systematic growth of, 407.
Geological Record, imperfection
of the, 439.
Geological Sections, 185, 193,
196, 198.
Geological Society of London,
2 97>.39 8 > 4 I 3>.4 I 7>423 ;
Geological succession, doctrine of,
59, 192, 201, 232, 250, 333.
Geological Survey of Great Bri-
tain, volcanic researches of,
270 ; work of, among Cambrian
and Silurian formations, 426 ;
foundation and objects of, 456.
Geological time, Buffon on, 91 ;
Lamarck on, 356 ; Darwin on,
439-.
Geologists, varied avocations of,
468.
Geology, historical method in,
2, 59, 90, 162, 192 ; and
speculation, 3, 6 ; and super-
stitions, 6 ; earliest pioneers
of, 7 ; Palasontological, first be-
ginnings of, 107, 117,118, 119,
1 39 ; modern development of,
349.. 355, 358, 364, 4oi ;
Physiographical, early observa-
tions in, 121, 1 60, 162 ; Vol-
canic, 127, 133, 140, 147, 162
[see also Volcanoes] ; first use
of term, 186 ; experimental
research in, 190, 317; Strati-
graphical, rise of in France,
333; in England, 378 ; re-
markable advance of, 400,438 ;
rise and development of Gla-
cial, 442 ; rise of Petrograph-
ical, 462 ; lies open to all
observers, 469.
Germany, basalts of, 147, I57 r
160, 221, 242, 249; ancient
volcanic rocks of, 271.
Gesner, Conrad, 45.
Giant's Causeway, 146, 147, 150.
Giraud-Soulavie, 338-341, 401.
Glacier action, Playfair on, 314,
442 ; in Britain, 446, 447.
Glaser, G., 451.
Glass, Hall's observations on slow
cooling of, 319.
Gneisses, Pre-Cambrian, 435.
Granite, De Saussure on, 188;
Werner on, 214, 230, 232;
Von Buch on, 251 ; Hutton
on, 290, 307 ; Lamarck on,
362.
Greece, earliest geological ideas
in, 7, 28, 33 ; subject to earth-
quakes, 13.
Greenough, G. B., 336, 453,
456.
Greywacke, 409, 410, 429.
Griffith, R., 455.
Guettard, J. E., early career of,
105 ; drawn to Geology
through Botany, 106 ; neglect
of work of, 1 08 ; early min-
eralogical surveys of, 1 1 o ; on
geology of Paris basin, 1 1 6 ;
palaeontological work of, 1 1 7,
1 1 8, 119, 140; on physio-
graphy, 121; on effects of rain
and springs, 121 ; on work of
the sea, 122 ; on rivers, 123 ;
on the sea-bottom, 1 24 ; on
limit of wave-erosion, 125 ;.
Index
479
on denudation, 126, 139, 159;
volcanic discovery made by,
127, 1 40; on Basalt, 135,149,
223 ; his character as drawn
by Condorcet, 137; his service
in regard to palaeontological
geology, 401.
Haidinger, W., 252.
Hall, Sir James, 292, 298, 302,
313, 317-325, 328.
Harz, geology of the, 196.
Hauer, Franz Ritter von, 254.
Hay-Cunningham, R. J., 269.
Hayden, F.V., 4 6i.
Heat, effects of, influenced by
pressure, 301, 323.
Hercules in geological myths, 7.
Herodotus, geological conceptions
of, 7 ; on the Nile, 28, 32, 36;
on fossil shells, 33.
Hooke, Robert, on methods of
research in natural science, 49
note ; his contributions to geo-
logy, 68; on change of the
earth's centre of gravity, 70 ;
on the former length of a day
and of a year, 70 note; on
fossils as geological records, 71;
on volcanoes, 72.
Homer, Leonard, 297.
Homes, M., 254.
Humboldt, A. von, 245, 246,
447-
Hunt, T. S., 436.
Huronian rocks, 436.
Hutton, J., 188, 191, 218, 258;
birth and early training of, 28 1 ;
takes to farming, 282, 284 ;
led to take interest in geology,
283 ; goes to Flanders, 283 ;
settles in Edinburgh, 284 ; his
scientific acquirements, 286 ;
his experiment on the eating
of snails, 288; his Theory of the
Earth, published, 289, 294; on
igneous rocks, 259, 290 ; his
geological excursions, 291 ; on
the significance of an uncon-
formability among rocks, 291;
his personal characteristics, 293 ;
attacked by De Luc and Kir-
wan, 296, 329; account of his
system, 298 ; on composition
of the land, 300; on action of
subterranean heat, 301 ; on
supposed igneous origin of
flint, 301, 361 ; on influence of
pressure on rocks in modifying
effects of heat, 301, 323; on
disturbance of strata, 302 ; on
the cause of these disturb-
ances, 303; on origin of vol-
canoes, 304 ; on whinstone,
305; on granite, 307; on min-
eral veins, 309; on metamor-
phism, 310; on the degradation
of the land, 311; his reliance
on observation, 315; his circle
of friends, 315 ; his relation
to the doctrine of geological
succession, 334.
Ice, disputed action of, in Post-
Tertiary Geology, 445, 448.
Infiltration in the consolidation
of rocks, Lamarck on, 361.
Ireland, Griffith's Map of, 453.
Ischia, 20.
Islands, Strabo on origin of, 20 ;
Ovid on, 38.
Jameson, R., 211, 213, 218, 219,
226, 227, 239, 264, 265, 326,
402.
{amieson, T. F., 449.
apan, geological and seismolog-
ical surveys of, 457.
{enzsch, G., 467.
ukes, J. B., 313.
Jurassic formations, 381, 392,
441.
480
Index
Jussieu, the Brothers, 106.
Keferstein, C., 197, 201, 222,
244, 408.
Kennedy, Robert, 322.
King, Clarence, 461.
Kirwan, R., 296, 316, 329.
Knorr, G. W., his plates of fos-
sils, etc., 101.
Lake District, ancient volcanic
rocks of, 266.
Lake Superior, pre - Cambrian
rocks of, 435.
Lamanon, 343, 371.
Lamarck, early career of, 345 ;
devotes himself to botany, 347;
publishes his Flore Franfaisc,
347 ; becomes Professor of
Zoology, 348 ; his contribu-
tions to geology, 349; founder
of invertebrate Palaeontology,
349 ; publishes his Hydrogeo-
k&*> 35 5 contributions to
evolution, 350; on origin of
mountains and valleys, 351 ;
on action of terrestrial waters,
353; on origin of the ocean-
basin, 353 ; on the use of
organic remains in the rocks,
355? 358 ; on the order and
antiquity of Nature, 356 ; on
antiquity of the earth, 356 ;
on interchange of land and sea,
3 5 7 ; on origin of the calcareous
material in the earth's crust,
358; on origin of limestone,
359 ; on the condition and
thickness of the earth's crust,
359; on the Pouvoir de la
Vie, 360 ; on consolidation of
rocks, 361; on granite, 362;
fate of his Hydrogeologte, 374;
his services to palaeontology,
401.
Land, submergence and elevation
of, 20, 34, 37; gain of, by
river deposits, 28, 29.
Landslips, Guettard on, 122.
Lang, K. N., his Historia Lapl-
dum, 98.
Lapworth, Prof. C., 441.
Laurentian rocks, 436.
Lava, Hutton on " unerupted,"
35;
Lavoisier, 1 15, 343.
Legends, geological origin of
some, 6.
Lehmann, J. G., 180, 195, 233,
33<5> 401-
Leibnitz, cosmology of, 8i; re-
cognized the co-operation of
hypogene and epigene forces in
geological history, 82 ; on
earthquakes and volcanoes, 82;
on fossils, 83.
Leonhard, K. C. von, 262.
Lesley, J. P., 460.
Lhuyd, Edward, on Fossils, 77,
117.
Lias, outcrop of, traced by Strange,
337; zonal stratigraphy of,
.441.
Life, speculations on evolution of,
^87.
Linnaeus, 189.
Lipari Isles, 15, 20.
Lister, Martin, on fossils, 76,
336 ; on mineralogical maps,
449-
Littoral fossils, 344, 355, 358.
Logan, W. E., 435.
Lonsdale, W., 431.
Lucretius, cited, 13 ; on earth-
quakes, 1 6.
Lyell, C., 159, 311, 313, 403,
411, 414.
Macculloch, J., 261, 454.
Maclaren, C., 269.
Maclure, W., 435, 458.
Index
i
Maillet, Benoit de, his Telliamed,
84.
Majoli on Fossils, 53, 64.
Malesherbes, C. G. de L., 128,
145.
Mallet, R., 277.
Man, speculations as to origin of,
88.
Maps, earliest geological, 77, III,
112, 115, 139, 198, 449.
Mattioli, on the materia pinguis,
5 2 :
Mediterranean basin, favourable
for the study of geological
features, 9, 10, 1 1.
Mercati on Fossils, 52.
Metamorphic rocks, 436.
Metamorphism, Hutton on, 310.
Michell, J., 273, 277, 378.
Michel-Levy, A., 271, 467.
Milne, J., 279.
Mineral and Fossil collections,
early examples of, 52, 68, 78,
98, 101, 102.
Mineralogy, early cultivation of,
140 ; Werner's services to,
2IO.
Mines, foundation of British
School of, 456, 457.
Miocene, 404.
Monte Nuovo, 47, 61.
Montlosier, Comte de, 159, 174,
248, 257.
Moro, Anton-Lazzaro, his geo-
logical theories, 61.
Mountains, geological influence
of, 10; origin of, 57, 90; dif-
ferent ages of, 57; Pallas on
formation of, 180; scenery of,
formerly considered repulsive,
182; de Saussure's success in
kindling a love of, 182 ; La-
marck on origin of, 351.
Murchison, R. I., 159; early re-
searches of, on ancient volcanic
rocks, 268, 420; his birth and
early career, 412 ; becomes a
geologist, 41 3 ; begins an attack
on the " interminable Grey-
wacke," 414 ; establishes the
"Silurian system," 418; associ-
ated with Sedgwick in found-
ing the Devonian system, 429;
personal characteristics of, 433 ;
appointed Director-General of
Geological Survey, 457.
Murray, Alexander, 436.
Myths, geological origin of, 6, 7.
Naumann, C. F., 402.
Neptunists, 218, 246, 247, 257,
259, 262, 269, 328, 331.
Newberry, J. S., 461.
Nicol, W., 463, 465.
Nile, River, u, 28, 29, 32, 36.
Ocean, theory of a former uni-
versal, 60, 62, 90, 214, 217,
220, 230.
Old Red Sandstone, 408, 430,
432.
O/<?<?//#.r-zone, 442.
Omalius d'Halloy, J. B., 377, 402.
Olivi on Fossils, 53.
Oolitic formations, 381, 392,441.
Oppel, Dr. A., 441.
Organic remains in relation to
the doctrine of geological suc-
cession, 335; as guides in stra-
tigraphy, 440 [See Fossils].
Ovid on the Pythagorean philo-
sophy, 37; on islands, 38.
Packe, C, 450.
Palaeontology. See Geology,
Palasontological.
Palaeozoic rocks, elaboration of
stratigraphy of, 410-432 ; vol-
canic series, 264, 266, 267.
Palassou, 452.
Palissy, Bernard, 104, 1 1 8.
Pallas, P. S., 178.
2H
482
Index
Paris, Academy of Sciences of,
107, 114, 137, 155, 173,234.;
influence of Tertiary Basin of,
on geological progress, 1 1 6,
341-345, 363-372-
Pelagic fossils, 344, 355, 358.
Peneius, River, n.
Percy, J., 457.
Perry, A., 277.
Petrography, earliest essay in, 1 6 ;
de Saussure's experimental
work in, 189 ; Werner's con-
tributions to, 213, 230, 238 ;
modern development of, 462.
Phillips, John, 381.
Phlegraean Fields, 19.
Physical Geography, Desmarest
on, 168.
Physiography. See Geology,
Physiographical.
Plants and Animals, Lamarck on
geological action of, 260.
Plastic force in Nature, supposed
to imitate organic bodies, 16,
45 So, 5 2 > 77.
Plato on source of rivers, 28.
Playfair, J., 259, 261, 281, 287,
290, 291, 292,295, 296, 297,
310, 312, 314,316, 325, 351,
361, 442.
Playfair, Lyon, 457.
Plication, Hall's experimental
illustration of, 325.
Pliny, the Elder, 26 ; on earth-
quakes and volcanoes, 27.
Pliocene, 404.
Plot, Robert, on Fossils, 77.
Plutonists, 218, 259, 262, 269,
328, 331.
Po, River, 1 1 .
Pompeii, earthquake at, 22, 23,
27.
Porphyry, Werner on, 214;
Hutton on, 305.
Poseidon, in geological myths, 7.
Powell,]. D., 461.
Pre-Cambrian rocks, 435.
Present, as a Key to the Past,
298.
Pressure, influence of, in modify-
ing effects of heat, 301, 323.
Primitive rocks, 180, 195, 214,
222, 230,232, 310,409,435;
Lamarck's rejection of the term,
359> 362.
Primordial Fauna, 428.
Puy de Dome, 1 30.
Pyritous strata, spontaneous com-
bustion of, 76, 94, 274.
Pythagoras on the system of
Nature, 37.
Quenstedt, F. A. von, 441.
Ramsay, A. C., 313, 435, 439,
449> 457-
Raspe, R. E., 173.
Rath, G. vom, 467.
Ray, John, influence of orthodoxy
on, 73 ; his views on denuda-
tion, 74, 126; his opinions
on fossils, 74 ; on earthquakes
and volcanoes, 75 ; cited, 78.
Reuss, F. A., 402.
Rhineland, Basalt of, 147, 148,
1 60.
Rhinoceros, fossil, of Siberia, 1 79.
Rhone, River, 1 1.
Richardson, Dr. (Portrush), 328.
Richardson, Rev. B., 388.
Rivers, views of the Ancients
on geological action of, 28 ;
Guettard on, 123 ; Hutton
and Playfair on, 312; Lamarck
on, 351.
Rochefoucault, Due de la, 144,
145.
Rocks, threefold classification of,
180, 195, 196, 214; chrono-
logical sequence of, 194, 198 ;
geological succession of, 192,
201, 232, 250, 333 ; Lamarck
Index
483
on consolidation of, 361 ;
method of making thin slices
of, for microscopical examina-
tion, 463.
Rogers, H. D., 460.
Rogers, W. B., 421, 460.
Rome, earliest geological ideas
in, 7.
Rose, G., 467.
Rosenbusch, H., 467.
Rouelle, G. F., 342.
Royal Society, Curatorship of
Experiments in, 68 ; foreign
member of, 99, 100 ; collects
earthquake records, 272, 274;
assists Mallet's investigation
of earthquakes, 278.
Russia, early scientific survey of,
Sand, experiment in consolidation
of, 324.
Santorin, volcanic action at, 24.
Saussure, H. B. de, on valleys,
159 ; on the Alps, 181 ; in-
fluence of, in removing the
popular dislike of mountain
scenery, 182 ; on granite, 185,
307 ; on disturbed strata, 187,
302 ; on erosion of valleys,
1 88 ; experimental researches
of, on rocks, 190.
Saxony, Basalt of, 147, 157, 160,
221, 242, 249.
Sea, early observations on former
presence of, n, 33, 34, 36,
37> 38, 43, So, 5 1 , 5 2 53
55, 59, 60, 62, 70, 71, 84,
85, 90, 104, 118; supposed
to have subsided into earth's
interior, 66, 90, 93 ; origin
of salinity of, 62, 82, 124;
absence of erosion much below
surface of, 125.
Secondary rocks, 180, 195, 378,
38i, 397, 399,408,470.
Sedgwick, A., researches of, on
ancient volcanic rocks, 266 ;
on W. Smith, 395 ; associated
with Murchison, 412, 423 ;
birth and career of, 421 ; be-
comes Woodwardian Professor
of Geology, 42 1 ; in the Lake
District, 423 ; in Wales, 424 ;
establishes the Cambrian system,
426 ; associated with Murchi-
son in forming the Devonian
system, 429 ; personal charac-
teristics of, 433.
Seismology, rise of, as a branch
of science, 277.
Seneca, his Natural Questions,
21 ; on the system of Nature,
21 ; on earthquakes, 22 ; on
volcanoes, 24.
Severinus, Peter, cited, 49.
Scheuchzer, J. J., geological writ-
ings of, 98-100.
Scotland, volcanic geology of
Western Isles of, 148, 256,
264 ; volcanic rocks of central,
264, 269, 287'; granite of,
291 ; unconformable rocks in,
292, 303 ; eruptive rocks in,
305 ; Macculloch's Geological
Map of, 454.
Scrope, G. P., 109, 128.
Siberia, fossil pachyderms in
frozen soil of, 178.
Silesia, Basalt of, 147, 160.
Silica, Lamarck's view of relative
importance of, 361.
Silurian fossils, first published
illustrations of, 1 17.
Silurian system, established by
Murchison, 418 ; his mono-
graph on, 420 ; application of
zonal stratigraphy to, 441.
Smith, William, birth and early
career of, 381; becomes land-
surveyor, 382; his first geolog-
ical expedition, 383 ; acquires
4 8 4
Index
a detailed knowledge of the
Secondary formations, 386,
388; his "Table of Strata,"
388 ; collects materials for a
geological map of England,
389 ; settles in London, 390 ;
publishes his Map, 391; value
of his work among the Jurassic
formations, 392 ; involved in
financial difficulties, 393 ; re-
ceives the Wollaston medal,
395; his personal appearance,
395 ; his publications, 396 ;
his services to Stratigraphy,
401 ; limits of his stratigraph-
ical knowledge, 409 ; descrip-
tion of his Map, 452.
Smyth, Warington W., 457.
Soland, Aime" de, 108.
Somma, dykes of, 321.
Sorby, H. C., 465.
Spallanzani, 256.
Springs, early conceptions of
origin of, 28, 31, 6 1, 74.
Staffa, 148.
Stars, supposed influence of, in
the production of "figured
stones," 45, 50, 52.
Steno, Nicholas, career of, 53;
on fossil sharks' teeth, 54; his
geological treatise, 5 5 ; on stra-
tified formations, 55 ; on dis-
turbances of strata, 56, 57,
302, 303; on erosion of strata,
57; on Fossils, 58; on geolog-
ical history, 59.
Strabo on Vale of Tempe, 8 ; on
River Alpheus, 8 ; on statues
said to have been brought from
Troy, 8; on the Memnonium,
9; on the exodus of the Cim-
bri, 9 ; character of his Geo-
graphy, 1 8 ; on volcanoes and
earthquakes, 1 8, 19, 304; on
origin of islands, 20; on hydro-
graphy of Mediterranean basin,
29 ; on deltas, 30 ; on rivers,
31; on displacing action of
vegetable roots, 31; on the
final destruction of the human
race, 32 ; on fossils, 34 ; on
former geological changes, 36.
Strachey, John, 194, 378.
Strange, John, 336.
Strata, inferences from vertical,
185, 188, 199, 221.
Stratification, Steno on, 55; dis-
turbances of 57; de Maillet
on, 86 ; de Saussure on, 185,
1 88; Strachey on, 194;
Fuchsel on, 198.
Stratigraphy, early progress of,
56, 194, 198, 333.
Strato on geological changes in
Egypt, 33-
Stukeley, W., 272.
Supernatural, decay of the, in in-
terpretations of topographical
features, 8.
Surveys, national geological, 456.
Tempe, explanations of origin of
Vale of, 7.
Tertiary Rocks, 180, 195, 341,
345, 363, 397, 399> 44, 4 8 ,
470.
Text books of Geology, 401.
Theophrastus on stones, 1 6 ; on
a plastic virtue in Nature, 16,
, 45 *
Thessaly, draining of lake in, 7.
Thuringer Wald, geology of the,
197.
Tiber, River, 1 1.
Transition Rocks of Werner, 214,
220, 231, 409, 470 ; early re-
searches in, 410; Murchison's
researches among, 414, 417,
419, 429; of America, 459,
460.
Trappean Rocks, 264, 265, 267.
Travel, rise of Geological, 176.
Index
Trilobites, first recognition of,
117.
Uniformitarianism in Geology,
i.99 43> 47 2 -
United States, volcanic geology
of, 271; geologists of, on river
erosion, 313 ; early geological
maps of, 458.
Universal formations of Werner,
212, 214, 215, 230.
Vallisneri, Antonio, 60.
Valleys, origin of, 57, 94, 159,
188, 312, 351.
Vanuxem, L., 460.
Venetz, J., 442.
Vesuvius, 10 ; recognised by
Strabo to be a volcano, 1 8 ;
eruption of in A.D. 79, 23, 27;
experiments in fusion of lavas
of, 322.
Vinci, Leonardo da, 50.
Vivarais, geology of the, 338.
Voigt,J. K. W., 223.
Volcanic geology, 127, 133, 140,
162.
Volcanic rocks, 195 ; interca-
lated among ancient geological
formations, 259, 339 ; ascer-
tained to be of all geological
periods, 263 ; Tertiary, 260 ;
Carboniferous, 264, 271 ; Old
Red Sandstone and Devonian,
264, 266, 270, 271 ; Silurian,
266, 267 ; Cambrian, 267 ;
Permian, 271.
Volcanoes, in Mediterranean
basin, 10; Aristotle's explana-
tion of, 15 ; Lucretius on, 17;
as safety-valves, antiquity of the
doctrine of, 19 ; Seneca on, 24;
appealed to in the Middle Ages
as agents in the accumulation
of the fossiliferous formations,
47, 53, 62, 64 ; supposed to
be due to combustion of in-
flammable substances, 25, 56,
57> 60, 73, 75, 80, 82, 93,
133, 156, 225; attributed to
spontaneous decomposition of
iron-pyrites, 76, 94, 274; sup-
posed modern origin of, 82,
93, 224, 225, 258 ; first dis-
covery of extinct, in France,
127-135, 339 ; connected with
internal heat of the globe, 255 ;
supposed connection of with
electricity, 258.
Vulcanists, 133, 136, 218, 224,
246, 247, 252, 257,262, 327,
33*.
Walch, J. E. I., his Das SteinreicA,
101 ; continued G. W. Knorr's
work on Fossils, 102.
Wales, volcanic geology of, 267,
268, 270.
Wallerius, 189.
Weather, influence of on earth-
quakes and volcanoes, 14, 19,
27.
Webster, T., 396.
Werner, A. G., forestalled by
Guettard in his explanation of
origin of Basalt, 136, 156,226;
opposed volcanic theories, 175,
222, 225; on aqueous origin
of granite, 185, 290, 307 ;
wide influence of, 201 ; popu-
larity of, 202; childhood and
education of, 203; training of,
in mining, 204; at Leipzig
University, 205; first published
essay of, 225 ; appointed to
Freiberg Academy, 206 ; per-
sonal appearance and charm of,
207; style of lecturing of, 208,
233, 235 ; character of his
teaching, 209, 238 ; method-
ical characteristics of, 209, 230,
231; mineralogical nomencla-
4 86
Index
ture of, 210; "universal for-
mations" of, 212, 213, 214,
215, 230; his classification and
chronological arrangement of
rocks, 213, 230, 333 ; his ex-
planation of the origin of rocks,
215; his theory of a universal
ocean and of chemical precipi-
tates, 214, 217, 220; on dis-
turbance in the earth's crust,
221, 228, 302 ; his contro-
versy about Basalt, 223, 226 ;
on nature of volcanoes, 224,
226; on veins, 229, 308, 309;
his dislike of writing, 233 ;
source of his influence, 236;
his services to science, 237,
462 ; loyalty of his followers
to, 240.
Wernerian School of Geology,
237, 239 ; decline of, 241,
244, 246, 250, 251,252,254,
330.
Wernerian Society, foundation
of, 327, 33-
Wind, important part assigned
to, by the ancients in subter-
ranean phenomena, 14, 16, 19,
23, 25, 26, 27, 38, 271.
Whinstone, Hutton on, 305 ;
Hall's experiments with, 320 ;
resembles lava, 321.
Whiston, W., his New Theory of
the Earth, 67.
Whitehurst, John, 380.
Widenmann, J. F. W., 224.
Witham, H., 463.
Woodward, John, his geological
views, 67.
Xanthus the Lydian, 33.
Xenophanes of Colophon, 33.
Zirkel, F., 467.
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