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History of Science

91

leads to its liquefaction, and ultimate consolidation-- the aforetime nebulae becoming in the end a dark or planetary star.

The exact correlation which Lockyer attempts to

point out between successive stages of meteoric condensation and the various types of observed stellar bodies

does not meet with unanimous acceptance. Mr.

Ranyard, for example, suggests that the visible nebulae may not be nascent stars, but emanations from stars,

and that the true pre-stellar nebulae are invisible until condensed to stellar proportions. But such details

aside, the broad general hypothesis that all the bodies of the universe are, so to speak, of a single species-- that nebulae (including comets), stars of all types, and planets, are but varying stages in the life history of a single race or type of cosmic organisms--is accepted

by the dominant thought of our time as having the highest warrant of scientific probability.

All this, clearly, is but an amplification of that nebular hypothesis which, long before the spectroscope gave

us warrant to accurately judge our sidereal neighbors, had boldly imagined the development of stars out of nebulae and of planets out of stars. But Lockyer's hypothesis does not stop with this. Having traced the developmental process from the nebular to the dark star, it sees no cause to abandon this dark star to its

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History of Science

92

fate by assuming, as the original speculation assumed,

that this is a culminating and final stage of cosmic existence. For the dark star, though its molecular activities

have come to relative stability and impotence,

still retains the enormous potentialities of molar motion; and clearly, where motion is, stasis is not. Sooner

or later, in its ceaseless flight through space, the dark star must collide with some other stellar body, as Dr. Croll imagines of the dark bodies which his "pre-nebular theory" postulates. Such collision may be long

delayed; the dark star may be drawn in comet-like circuit about thousands of other stellar masses, and be

hurtled on thousands of diverse parabolic or elliptical orbits, before it chances to collide--but that matters

not: "billions are the units in the arithmetic of eternity," and sooner or later, we can hardly doubt, a collision

must occur. Then without question the mutual

impact must shatter both colliding bodies into vapor, or vapor combined with meteoric fragments; in short, into a veritable nebula, the matrix of future worlds.

Thus the dark star, which is the last term of one series of cosmic changes, becomes the first term of another

series--at once a post-nebular and a pre-nebular condition; and the nebular hypothesis, thus amplified,

ceases to be a mere linear scale, and is rounded out to connote an unending series of cosmic cycles, more nearly satisfying the imagination.

In this extended view, nebulae and luminous stars are

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93

but the infantile and adolescent stages of the life history of the cosmic individual; the dark star, its adult

stage, or time of true virility. Or we may think of the shrunken dark star as the germ-cell, the pollen-grain, of the cosmic organism. Reduced in size, as becomes a germ-cell, to a mere fraction of the nebular body from which it sprang, it yet retains within its seemingly nonvital body all the potentialities of the original organism, and requires only to blend with a fellow-cell to

bring a new generation into being. Thus may the cosmic race, whose aggregate census makes up the

stellar universe, be perpetuated--individual solar systems, such as ours, being born, and growing old, and

dying to live again in their descendants, while the universe as a whole maintains its unified integrity throughout

all these internal mutations--passing on, it may be,

by infinitesimal stages, to a culmination hopelessly beyond human comprehension.

III. THE NEW SCIENCE OF PALEONTOLOGY

WILLIAM SMITH AND FOSSIL SHELLS

Ever since Leonardo da Vinci first recognized the true character of fossils, there had been here and there a man who realized that the earth's rocky crust

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94

is one gigantic mausoleum. Here and there a dilettante had filled his cabinets with relics from this monster crypt; here and there a philosopher had pondered

over them--questioning whether perchance they had once been alive, or whether they were not mere

abortive souvenirs of that time when the fertile matrix of the earth was supposed to have

"teemed at a birth

Innumerous living creatures, perfect forms,

Limbed and full grown."

Some few of these philosophers--as Robert Hooke and Steno in the seventeenth century, and Moro, Leibnitz, Buffon, Whitehurst, Werner, Hutton, and others in the eighteenth--had vaguely conceived the importance of

fossils as records of the earth's ancient history, but the wisest of them no more suspected the full import of the story written in the rocks than the average stroller in

a modern museum suspects the meaning of the hieroglyphs on the case of a mummy.

It was not that the rudiments of this story are so very hard to decipher--though in truth they are hard enough--but rather that the men who made the attempt had all along viewed the subject through an atmosphere of preconception, which gave a distorted

image. Before this image could be corrected it was necessary that a man should appear who could see

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95

without prejudice, and apply sound common-sense to what he saw. And such a man did appear towards the

close of the century, in the person of William Smith, the English surveyor. He was a self-taught man, and perhaps the more independent for that, and he had the

gift, besides his sharp eyes and receptive mind, of a most tenacious memory. By exercising these faculties, rare as they are homely, he led the way to a

science which was destined, in its later developments, to shake the structure of established thought to its foundations.

Little enough did William Smith suspect, however,

that any such dire consequences were to come of his act when he first began noticing the fossil shells that here and there are to be found in the stratified rocks and soils of the regions over which his surveyor's duties led him. Nor, indeed, was there anything of such apparent revolutionary character in the facts which he

unearthed; yet in their implications these facts were the most disconcerting of any that had been revealed since the days of Copernicus and Galileo. In its bald essence, Smith's discovery was simply this: that the

fossils in the rocks, instead of being scattered haphazard, are arranged in regular systems, so that any

given stratum of rock is labelled by its fossil population; and that the order of succession of such groups of

fossils is always the same in any vertical series of strata

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96

in which they occur. That is to say, if fossil A underlies fossil B in any given region, it never overlies it in

any other series; though a kind of fossils found in one set of strata may be quite omitted in another. Moreover, a fossil once having disappeared never reappears

in any later stratum.

From these novel facts Smith drew the commonsense inference that the earth had had successive populations of creatures, each of which in its turn had become extinct. He partially verified this inference by

comparing the fossil shells with existing species of similar orders, and found that such as occur in older

strata of the rocks had no counterparts among living species. But, on the whole, being eminently a practical man, Smith troubled himself but little about the inferences that might be drawn from his facts. He was

chiefly concerned in using the key he had discovered

as an aid to the construction of the first geological map of England ever attempted, and he left to others the untangling of any snarls of thought that might seem

to arise from his discovery of the succession of varying forms of life on the globe.

He disseminated his views far and wide, however, in the course of his journeyings--quite disregarding the fact that peripatetics went out of fashion when the printing-press came in--and by the beginning of the nineteenth century he had begun to have a following

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97

among the

geologists of England. It must not for

a

moment be

supposed, however, that his contention

regarding

the succession of strata met with immediate

or general acceptance. On the contrary, it was most bitterly antagonized. For a long generation after the discovery was made, the generality of men, prone as always to strain at gnats and swallow camels, preferred

to believe that the fossils, instead of being deposited in successive ages, had been swept all at once into their present positions by the current of a mighty flood--and that flood, needless to say, the Noachian deluge. Just

how the numberless successive strata could have been laid down in orderly sequence to the depth of several miles in one such fell cataclysm was indeed puzzling,

especially after it came to be admitted that the heaviest fossils were not found always at the bottom; but to

doubt that this had been done in some way was rank heresy in the early days of the nineteenth century.

CUVIER AND FOSSIL VERTEBRATES

But once discovered, William Smith's unique facts

as to the succession of forms in the rocks would not down. There was one most vital point, however, regarding which the inferences that seem to follow from

these facts needed verification--the question, namely, whether the disappearance of a fauna from the register

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98

in the rocks really implies the extinction of that fauna. Everything really depended upon the answer to that question, and none but an accomplished naturalist

could answer it with authority. Fortunately, the most authoritative naturalist of the time, George Cuvier, took the question in hand--not, indeed, with the idea

of verifying any suggestion of Smith's, but in the course of his own original studies--at the very beginning of

the century, when Smith's views were attracting general attention.

Cuvier and Smith were exact contemporaries, both men having been born in 1769, that "fertile year"

which gave the world also Chateaubriand, Von Humboldt, Wellington, and Napoleon. But the French naturalist was of very different antecedents from the English surveyor. He was brilliantly educated, had early

gained recognition as a scientist, and while yet a young man had come to be known as the foremost comparative anatomist of his time. It was the anatomical

studies that led him into the realm of fossils. Some bones dug out of the rocks by workmen in a quarry

were brought to his notice, and at once his trained eye told him that they were different from anything he had seen before. Hitherto such bones, when not entirely ignored, had been for the most part ascribed to giants of former days, or even to fallen angels. Cuvier soon showed that neither giants nor angels were in question, but elephants of an unrecognized species. Continuing

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his studies, particularly with material gathered from gypsum beds near Paris, he had accumulated, by the beginning of the nineteenth century, bones of about twenty-five species of animals that he believed to be different from any now living on the globe.

The fame of these studies went abroad, and presently

fossil bones poured in from all sides, and Cuvier's conviction that extinct forms of animals are represented

among the fossils was sustained by the evidence of many strange and anomalous forms, some of them of gigantic size. In 1816 the famous Ossements Fossiles,

describing these novel objects, was published, and vertebrate paleontology became a science. Among other

things of great popular interest the book contained the first authoritative description of the hairy elephant, named by Cuvier the mammoth, the remains of which

bad been found embedded in a mass of ice in Siberia in 1802, so wonderfully preserved that the dogs of the Tungusian fishermen actually ate its flesh. Bones of the same species had been found in Siberia several years before by the naturalist Pallas, who had also found the carcass of a rhinoceros there, frozen in a mud-bank; but no one then suspected that these were members of an extinct population--they were supposed to be merely transported relics of the flood.

Cuvier, on the other hand, asserted that these and the

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History of Science

 

 

 

100

other creatures

he described had lived and died

in the

region where

their remains were

found, and that

most

of them have

no

living representatives upon the

globe.

This, to be sure, was nothing more than William

Smith

had tried all along to establish regarding lower forms of

life; but flesh

and blood monsters appeal to the imagination

in a way quite beyond the power

of mere shells;

 

so the announcement of Cuvier's

discoveries aroused

the interest

of

the entire world, and the Ossements

Fossiles was

accorded a popular

reception seldom

 

given a work

of

technical science--a reception in

which the enthusiastic approval

of progressive geologists

was mingled with the bitter protests of the conservatives.

"Naturalists certainly have neither explored all the continents," said Cuvier, "nor do they as yet even know

all the quadrupeds of those parts which have been explored. New species of this class are discovered from

time to time; and those who have not examined with

attention all the circumstances belonging to these discoveries may allege also that the unknown quadrupeds,

whose fossil bones have been found in the strata of the earth, have hitherto remained concealed in

some islands not yet discovered by navigators, or in some of the vast deserts which occupy the middle of Africa, Asia, the two Americas, and New Holland.

"But if we carefully attend to the kind of quadrupeds

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