THE INTERACTION OF THE SCIENCES--WERNER, HUTTON, BLACK, HALL, WILLIAM
SMITH
The view expressed by Franklin regarding the existence of a fiery mass
underlying the crust of the earth was not in his time universally
accepted. In fact, it was a question very vigorously disputed what part
the internal or volcanic fire played in the formation and modification
of rock masses. Divergent views were represented by men who had come to
the study of geology with varying aims and diverse scientific schooling,
and the advance of the science of the earth's crust was owing in no
small measure to the interaction of the different sciences which the
exponents of the various points of view brought to bear.
Abraham Gottlob Werner (1750-1817) was the most conspicuous and
influential champion on the side of the argument opposed to the
acceptance of volcanic action as one of the chief causes of geologic
formations. He was born in Saxony and came of a family which had engaged
for three hundred years in mining and metal working. They were active in
Saxony when George Agricola prepared his famous works on metallurgy and
mineralogy inspired by the traditional wisdom of the local iron
industry. Werner's father was an overseer of iron-works, and furnished
his son with mineral specimens as playthings before the child could
pronounce their names. In 1769 Werner was invited to attend the newly
founded Bergakademie (School of Mines) at Freiberg. Three years later he
went to the University of Leipzig, but, true to his first enthusiasm,
wrote in 1774 concerning the outward characteristics of minerals (_Von
den äusserlichen Kennzeichen der Fossilien_). The next year he was
recalled to Freiberg as teacher of mineralogy and curator of
collections. He was intent on classification, and might be compared in
that respect with the naturalist Buffon, or the botanist Linnæus. He
knew that chemistry afforded a surer, but slower, procedure; his was a
practical, intuitive, field method. He observed the color, the hardness,
weight, fracture of minerals, and experienced the joy the youthful mind
feels in rapid identification. He translated Cronstedt's book on
mineralogy descriptive of the practical blow-pipe tests. After the
identification of minerals, Werner was interested in their discovery,
the location of deposits, their geographical distribution, and the
relative positions of different kinds of rocks, especially the constant
juxtaposition or superposition of one stratum in relation to another.
Werner was an eloquent, systematic teacher with great charm of manner.
He kept in mind the practical purposes of mining, and soon people
flocked to Freiberg to hear him from all the quarters of Europe. He had
before long disciples in every land. He saw all phenomena from the
standpoint of the geologist. He knew the medicinal, as well as the
economic, value of minerals. He knew the relation of the soil to the
rocks, and the effects of both on racial characteristics. Building-stone
determines style of architecture. Mountains and river-courses have
bearing on military tactics. He turned his linguistic knowledge to
account and furnished geology with a definite nomenclature. Alex. v.
Humboldt, Robert Jameson, D'Aubuisson, Weiss (the teacher of Froebel),
were among his students. Crystallography and mineralogy became the
fashion. Goethe was among the enthusiasts, and philosophers like
Schelling, under the spell of the new science, almost deified the
physical universe.
Werner considered all rocks as having originated by crystallization,
either chemical or mechanical, from an aqueous solution--a universal
primitive ocean. He was a Neptunist, as opposed to the Vulcanists or
Plutonists, who believed in the existence of a central fiery mass.
Werner thought that the earth showed universal strata like the layers of
an onion, the mountains being formed by erosion, subsidence, cavings-in.
In his judgment granite was a primitive rock formed previous to animal
and vegetable life (hence without organic remains) by chemical
precipitation. Silicious slate was formed later by mechanical
crystallization. At this period organized fossils first appear.
Sedimentary rocks, like old red sandstone, and, according to Werner,
basalt, are in a third class. Drift, sand, rubble, boulders, come next;
and finally volcanic products, like lava, ashes, pumice. He was quite
positive that all basalt was of aqueous origin and of quite recent
formation. This part of his teaching was soon challenged. He was truer
to his own essential purposes in writing a valuable treatise on
metalliferous veins (_Die Neue Theorie der Erzgänge_), but even there
his general views are apparent, for he holds that veins are clefts
filled in from above by crystallization from aqueous solution.
Before Werner had begun his teaching career at Freiberg, Desmarest, the
French geologist, had made a special study of the basalts of Auvergne.
As a mathematician he was able to make a trigonometrical survey of that
district, and constructed a map showing the craters of volcanoes of
different ages, the streams of lava following the river courses, and the
relation of basalt to lava, scoria, ashes, and other recognized products
of volcanic action. In 1788 he was made inspector-general of French
manufactures, later superintendent of the porcelain works at Sèvres. He
lived to the age of ninety, and whenever Neptunists would try to draw
him into argument, the old man would simply say, "Go and see."
James Hutton (1726-1797), the illustrious Scotch geologist, had
something of the same aversion to speculation that did not rest on
evidence; though he was eminently a philosopher in the strictest sense
of the word, as his three quarto volumes on the _Principles of
Knowledge_ bear witness. Hutton was well trained at Edinburgh in the
High School and University. In a lecture on logic an illustrative
reference to _aqua regia_ turned his mind to the study of chemistry. He
engaged in experiments, and ultimately made a fortune by a process for
the manufacture of sal ammoniac from coal-soot. In the mean time he
studied medicine at Edinburgh, Paris, and Leyden, and continued the
pursuit of chemistry. Then, having inherited land in Berwickshire, he
studied husbandry in Norfolk and took interest in the surface of the
land and water-courses; later he pursued these studies in Flanders.
During years of highly successful farming, during which Hutton
introduced new methods in Berwickshire, he was interested in
meteorology, and in geology as related to soils. In 1768, financially
independent, Dr. Hutton retired to reside in Edinburgh.
He was very genial and sociable and was in close association with Adam
Smith, the economist, and with Black, known in the history of chemistry
in connection with carbonic acid, latent heat, and experiments in
magnesia, quicklime, and other alkaline substances (1777). Playfair,
professor of mathematics, and later of natural philosophy, was Hutton's
disciple and intimate friend. In the distinguished company of the Royal
Society of Edinburgh, established in 1782, the founder of dynamic
geology was stimulated by these and other distinguished men like William
Robertson, Lord Kames, and Watt. The first volume of the _Transactions_
contains his _Theory of Rains_, and the first statement of his famous
_Theory of the Earth_. He was very broad-minded and enthusiastic and
would rejoice in Watt's improvements of the steam engine or Cook's
discoveries in the South Pacific. Without emphasizing his indebtedness
to Horace-Bénédict de Saussure, physicist, geologist, meteorologist,
botanist, who gave to Europeans an appreciation of the sublime in
nature, nor dwelling further on the range of Hutton's studies in
language, general physics, etc., it is already made evident that his
mind was such as to afford comprehensiveness of view.
He expressed the wish to induce men who had sufficient knowledge of the
particular branches of science, to employ their acquired talents in
promoting general science, or knowledge of the great system, where ends
and means are wisely adjusted in the constitution of the material
universe. Philosophy, he says, is surely the ultimate end of human
knowledge, or the object at which all sciences properly must aim.
Sciences no doubt should promote the arts of life; but, he proceeds,
what are all the arts of life, or all the enjoyments of mere animal
nature, compared with the art of human happiness, gained by education
and brought to perfection by philosophy? Man must learn to know himself;
he must see his station among created things; he must become a moral
agent. But it is only by studying things in general that he may arrive
at this perfection of his nature. "To philosophize, therefore, without
proper science, is in vain; although it is not vain to pursue science,
without proceeding to philosophy."
In the early part of 1785 Dr. Hutton presented his _Theory of the Earth_
in ninety-six pages of perfectly lucid English. The globe is studied as
a machine adapted to a certain end, namely, to provide a habitable world
for plants, for animals, and, above all, for intellectual beings capable
of the contemplation and the appreciation of order and harmony. Hutton's
theory might be made plain by drawing an analogy between geological and
meteorological activities. The rain descends on the earth; streams and
rivers bear it to the sea; the aqueous vapors, drawn from the sea,
supply the clouds, and the circuit is complete. Similarly, the soil is
formed from the overhanging mountains; it is washed as sediment into
the sea; it is elevated, after consolidation, into the overhanging
mountains. The earth is more than a mechanism, it is an organism that
repairs and restores itself in perpetuity. Thus Hutton explained the
composition, dissolution, and restoration of land upon the globe on a
general principle, even as Newton had brought a mass of details under
the single law of gravitation.
Again, as Newton had widened man's conception of space, so Hutton (and
Buffon) enlarged his conception of time. For the geologist did not
undertake to explain the _origin_ of things; he found no vestige of a
beginning,--no prospect of an end; and at the same time he conjured up
no hypothetical causes, no catastrophes, or sudden convulsions of
nature; neither did he (like Werner) believe that phenomena now present,
were once absent; but he undertook to explain all geological change by
processes in action now as heretofore. Countless ages were requisite to
form the soil of our smiling valleys, but "Time, which measures
everything in our _idea_, and is often deficient to our schemes, is to
nature endless and as nothing." The calcareous remains of marine animals
in the solid body of the earth bear witness of a period to which no
other species of chronology is able to remount.
Hutton's imagination, on the basis of what can be observed to-day,
pictured the chemical and mechanical disintegration of the rocks; and
saw ice-streams bearing huge granite boulders from the declivities of
primitive and more gigantic Alps. He believed (as Desmarest) that
rivulets and rivers have constructed, and are constructing, their own
valley systems, and that the denudation ever in progress would be
eventually fatal to the sustenance of plant and animal and man, if the
earth were not a renewable organism, in which repair is correlative with
waste.
All strata are sedimentary, consolidated at the bottom of the sea by the
pressure of the water and by subterranean heat. How are strata raised
from the ocean bed? By the same subterranean force that helped
consolidate them. The power of heat for the expansion of bodies, is,
says Hutton (possibly having in mind the steam engine), so far as we
know, unlimited. We see liquid stone pouring from the crater of a lofty
volcano and casting huge rocks into mid-air, and yet find it difficult
to believe that Vesuvius and Etna themselves have been formed by
volcanic action. The interior of the planet may be a fluid mass, melted,
but unchanged by the action of heat. The volcanoes are spiracles or
safety-valves, and are widely distributed on the surface of the earth.
Hutton believed that basalt, and the whinstones generally, are of
igneous origin. Moreover, he put granite in the same category, and
believed it had been injected, as also metalliferous veins, in liquid
state into the stratified rocks. If his supposition were correct, then
granite would be found sending out veins from its large masses to pierce
the stratified rocks and to crop out where stratum meets stratum. His
conjecture was corroborated at Glen Tilt (and in the island of Arran).
Hutton was so elated at the verification of his view that the Scotch
guides thought he had struck gold, or silver at the very least. In the
bed of the river Tilt he could see at six points within half a mile
powerful veins of red granite piercing the black micaceous schist and
giving every indication of having been intruded from beneath, with great
violence, into the earlier formation.
Hutton felt confirmed in his view that in nature there is wisdom,
system, and consistency. Even the volcano and earthquake, instead of
being accidents, or arbitrary manifestations of divine wrath, are part
of the economy of nature, and the best clue we have to the stupendous
force necessary to heave up the strata, inject veins of metals and
igneous rocks, and insure a succession of habitable worlds.
In 1795 Dr. Hutton published a more elaborate statement of his theory in
two volumes. In 1802 Playfair printed _Illustrations of the Huttonian
Theory_, a simplification, having, naturally, little originality. Before
his death in 1797 Hutton devoted his time to reading new volumes by
Saussure on the Alps, and to preparing a book on _The Elements of
Agriculture_.
Sir James Hall of Dunglass was a reluctant convert to Hutton's system of
geology. Three arguments against the Huttonian hypothesis gave him cause
for doubt. Would not matter solidifying after fusion form a glass, a
vitreous, rather than a crystalline product? Why do basalts, whinstones,
and other supposedly volcanic rocks differ so much in structure from
lava? How can marble and other limestones have been _fused_, seeing that
they are readily calcined by heat? Hutton thought that the compression
under which the subterranean heat had been applied was a factor in the
solution of these problems. He was encouraged in this view by Black,
who, as already implied, had made a special study of limestone and had
demonstrated that lime acquires its causticity through the expulsion of
carbonic acid.
Hall conjectured in addition that the rate at which the fused mass
cooled might have some bearing on the structure of igneous rocks. An
accident in the Leith glass works strengthened the probability of his
conjecture and encouraged him to experiment. A pot of green bottle-glass
had been allowed to cool slowly with the result that it had a stony,
rather than a vitreous structure. Hall experimenting with glass could
secure either structure at will by cooling rapidly or slowly, and that
with the same specimen.
He later enclosed some fragments of whinstone in a black-lead crucible
and subjected it to intense heat in the reverberating furnace of an iron
foundry. (He was in consultation with Mr. Wedgwood on the scale of heat,
and with Dr. Hope and Dr. Kennedy, chemists.) After boiling, and then
cooling rapidly, the contents of the crucible proved a black glass. Hall
repeated the experiment, and cooled more slowly. The result was an
intermediate substance, neither glass nor whinstone--a sort of slag.
Again he heated the crucible in the furnace, and removed quickly to an
open fire, which was maintained some hours and then permitted to die
out. The result in this case was a perfect whinstone. Similar results
were obtained with regular basalts and different specimens of igneous
rock.
Hall next experimented with lava from Vesuvius, Etna, Iceland, and
elsewhere, and found that it behaved like whinstone. Dr. Kennedy by
careful chemical analysis confirmed Hall's judgment of the similarity
of these two igneous products.
Still later Hall introduced chalk and powdered limestone into porcelain
tubes, gun barrels, and tubes bored in solid iron, which he sealed and
brought to very high temperatures. He obtained, by fusion, a crystalline
carbonate resembling marble. Under the high pressure in the tube the
carbonic acid was retained. By these and other experiments this doubting
disciple confirmed Hutton's theory, and became one of the great founders
of experimental geology.
It remained for William Smith (1769-1839), surveyor and engineer, to
develop that species of chronology that Hutton had ascribed to organic
remains in the solid strata, to arrange these strata in the order of
time, and thus to become the founder of historic geology. For this task
his early education might at first glance seem inadequate. His only
schooling was received in an elementary institution in Oxfordshire. He
managed, however, to acquire some knowledge of geometry, and at eighteen
entered, as assistant, a surveyor's office. He never attained any
literary facility, and was always more successful in conveying his
observations by maps, drawings, and conversation than by books.
However, he early began his collection of minerals and observed the
relation of the soil and the vegetation to the underlying rocks. Engaged
at the age of twenty-four in taking levelings for a canal, he noticed
that the strata were not exactly horizontal, but dipped to the east
"like slices of bread and butter," a phenomenon he considered of
scientific significance. In connection with his calling he had an
opportunity of traveling to the north of England and so extended the
range of his observation, always exceptionally alert. For six years he
was engaged, as engineer, in the construction of the Somerset Coal
Canal, where he enlarged and turned to practical account his knowledge
of strata.
Collectors of fossils (as Lamarck afterwards called organic remains)
were surprised to find Smith able to tell in what formation their
different specimens had been found, and still more when he enunciated
the view that "whatever strata were to be found in any part of England
the same remains would be found in it and no other." Moreover, the same
order of superposition was constant among the strata, as Werner, of whom
Smith knew nothing, had indeed taught. Smith was able to dictate a
_Tabular View of British Strata_ from coal to chalk with the
characteristic fossils, establishing an order that was found to obtain
on the Continent of Europe as well as in Britain.
He constructed geological maps of Somerset and fourteen other English
counties, to which the attention of the Board of Agriculture was called.
They showed the surface outcrops of strata, and were intended to be of
assistance in mining, roadmaking, canal construction, draining, and
water supply. It was at the time of William Smith's scientific
discoveries that the public interest in canal transportation was at its
height in England, and his study of the strata was a direct outcome of
his professional activity. He called himself a mineral surveyor, and he
traveled many thousand miles yearly in connection with his calling and
his interest in the study of geology. In 1815 he completed an extensive
geological map of England, on which all subsequent geological maps have
been modeled. It took into account the collieries, mines, canals,
marshes, fens, and the varieties of soil in relation to the substrata.
Later (1816-1819) Smith published four volumes, _Strata Identified by
Organized Fossils_, which put on record some of his extensive
observations. His mind was practical and little given to speculation. It
does not lie in our province here to trace his influence on Cuvier and
other scientists, but to add his name as a surveyor and engineer to the
representatives of mineralogy, chemistry, physics, mathematics,
philosophy, and various industries and vocations, which contributed to
the early development of modern geology.
REFERENCES
Sir A. Geikie, _Founders of Geology_.
James Hutton, _Theory of the Earth_.
Sir Charles Lyell, _Principles of Geology_.
John Playfair, _Illustrations of the Huttonian Theory_.
K. A. v. Zittel, _History of Geology and Palæontology_.