Part 1

Transcriber’s Note

In the Plain Text version of this eBook, molecular structures in the Chemistry chapter will display correctly only when a fixed-width font is used. Other special situations in that chapter are discussed in the Transcriber’s Notes at the end of this eBook.

THE PROGRESS OF THE CENTURY

BY ALFRED RUSSEL WALLACE; PROF. WILLIAM RAMSAY; PROF. WILLIAM MATTHEW FLINDERS-PETRIE; SIR JOSEPH NORMAN LOCKYER; EDWARD CAIRD; WILLIAM OSLER; W. W. KEEN; PROF. ELIHU THOMSON; PRESIDENT THOMAS CORWIN MENDENHALL; SIR CHARLES WENTWORTH DILKE; CAPTAIN ALFRED T. MAHAN; ANDREW LANG; THOMAS C. CLARKE; CARDINAL JAMES GIBBONS; REV. ALEXANDER V. G. ALLEN; PROF. RICHARD J. H. GOTTHEIL; PROF. GOLDWIN SMITH

NEW YORK AND LONDON HARPER & BROTHERS PUBLISHERS 1901

Copyright, 1901, by HARPER & BROTHERS.

Copyright, 1901, by THE SUN PRINTING AND PUBLISHING ASSOCIATION.

_All rights reserved._

CONTENTS

PAGE EVOLUTION. BY ALFRED RUSSEL WALLACE, LL.D., D.C.L., F.R.S 3

CHEMISTRY. BY PROF. WILLIAM RAMSAY, PH.D., F.R.S., F.C.S., OFFICER OF THE LEGION OF HONOR 33

ARCHÆOLOGY. BY PROF. WILLIAM MATTHEW FLINDERS-PETRIE, D.C.L., LL.D., EDWARDS PROFESSOR OF EGYPTOLOGY, UNIVERSITY COLLEGE, LONDON 73

ASTRONOMY. BY SIR JOSEPH NORMAN LOCKYER, C.B., F.R.S., DIRECTOR OF SOLAR PHYSICS OBSERVATORY, SOUTH KENSINGTON 105

PHILOSOPHY. BY EDWARD CAIRD, LL.D., D.C.L., PROFESSOR OF MORAL PHILOSOPHY, GLASGOW 145

MEDICINE. BY WILLIAM OSLER, LL.D., PROFESSOR OF MEDICINE AND PHYSICIAN TO HOSPITAL, JOHNS HOPKINS MEDICAL SCHOOL 173

SURGERY. BY W. W. KEEN, M.D., LL.D., F.R.C.S. (HON.), PROFESSOR OF THE PRINCIPLES OF SURGERY AND OF CLINICAL SURGERY, JEFFERSON MEDICAL COLLEGE, PHILADELPHIA 217

ELECTRICITY. BY PROF. ELIHU THOMSON, A.M., PH.D., CHEVALIER AND OFFICER OF THE LEGION OF HONOR 265

PHYSICS. BY PRESIDENT THOMAS CORWIN MENDENHALL, PH.D., D.SC., LL.D., MEMBER NATIONAL ACADEMY OF SCIENCE 303

WAR. BY THE RIGHT HON. SIR CHARLES WENTWORTH DILKE, LL.M. 333

NAVAL SHIPS. BY CAPTAIN ALFRED T. MAHAN, LATE U.S.N., D.C.L., LL.D. 355

LITERATURE. BY ANDREW LANG, HON. FELLOW MERTON COLLEGE, OXFORD 389

ENGINEERING. BY THOMAS C. CLARKE. PAST PRESIDENT OF THE AMERICAN SOCIETY OF CIVIL ENGINEERS 421

RELIGION:

CATHOLICISM. BY CARDINAL JAMES GIBBONS 455

PROTESTANTISM. BY REV. ALEXANDER V. G. ALLEN, PROFESSOR OF CHURCH HISTORY IN THE EPISCOPAL THEOLOGICAL SCHOOL AT CAMBRIDGE, MASS. 477

THE JEWS AND JUDAISM. BY PROFESSOR RICHARD J. H. GOTTHEIL 498

FREE-THOUGHT. BY PROFESSOR GOLDWIN SMITH 539

EVOLUTION

Among the great and fertile scientific conceptions which have either originated or become firmly established during the nineteenth century, the theory of evolution, if not the greatest of them all, will certainly take its place in the front rank. As a partial explanation (for no complete explanation is possible to finite intelligence) of the phenomena of nature, it illuminates every department of science, from the study of the most remote cosmic phenomena accessible to us to that of the minutest organisms revealed by the most powerful microscopes; while upon the great problem of the mode of origin of the various forms of life—long considered insoluble—it throws so clear a light that to many biologists it seems to afford as complete a solution, in principle, as we can expect to reach.

THE NATURE AND LIMITS OF EVOLUTION

So many of the objections which are still made to the theory of evolution, and especially to that branch of it which deals with living organisms, rest upon a misconception of what it professes to explain, and even of what any theory can possibly explain, that a few words on its nature and limits seem to be necessary.

Evolution, as a general principle, implies that all things in the universe, as we see them, have arisen from other things which preceded them by a process of modification, under the action of those all-pervading but mysterious agencies known to us as “natural forces,” or, more generally, “the laws of nature.” More particularly the term evolution implies that the process is an “unrolling,” or “unfolding,” derived probably from the way in which leaves and flowers are usually rolled up or crumpled up in the bud and grow into their perfect form by unrolling or unfolding. Insects in the pupa and vertebrates in the embryo exhibit a somewhat similar condition of folding, and the word is therefore very applicable to an extensive range of phenomena; but it must not be taken as universally applicable, since in the material world there are other modes of orderly change under natural laws to which the terms development or evolution are equally applicable. The “continuity” of physical phenomena, as illustrated by the late Sir William Grove in 1866, has the same general meaning, but evolution implies more than mere continuity or succession—something like growth or definite change from form to form under the action of unchangeable laws.

The point to be especially noted here is, that evolution, even if it is essentially a true and complete theory of the universe, can only explain the existing conditions of nature by showing that it has been derived from some pre-existing condition through the action of known forces and laws. It may also show the high probability of a similar derivation from a still earlier condition; but the further back we go the more uncertain must be our conclusions, while we can never make any real approach to the absolute beginnings of things. Herbert Spencer, and many other thinkers before him, have shown that if we try to realize the absolute nature of the simplest phenomena, we are inevitably landed either in a contradiction or in some unthinkable proposition. Thus, suppose we ask, Is matter infinitely divisible, or is it not? If we say it is, we cannot think it out, since all infinity, however it may be stated in words, is really unthinkable.

If we say there is a limit—the ultimate atom—then, as all size is comparative, we can imagine a being to whom this atom seems as large as an apple or even a house does to us; and we then find it quite unthinkable that this mass of matter should be in its nature absolutely indivisible even by an infinite force. It follows that all explanations of phenomena can only be partial explanations. They can inform us of the last change or the last series of changes which brought about the actual conditions now existing, and they can often enable us to predict future changes to a limited extent; but both the infinite past and the remote future are alike beyond our powers. Yet the explanations that the theory of evolution gives us are none the less real and none the less important, especially when we compare its teachings with the wild guesses or the total ignorance of the thinkers of earlier ages.

THE RISE AND PROGRESS OF THE IDEA OF EVOLUTION

If we trace, however briefly, the gradual development of knowledge and speculation on this subject, we shall perhaps appreciate more fully the advance we have really made during the present century.

The first speculations on the nature and source of the phenomena of the universe, of which we have any knowledge, are those of the early Greek philosophers, such as Thales, Anaximander, Anaxagoras, and Empedocles; but as the more important of their teachings are embodied, with some approach to system and with much acuteness of reasoning, in the great poem of the Latin author Lucretius, “On the Nature of Things,” it will be sufficient to give a sketch of his main conclusions, making use of the excellent prose translation by Mr. H. A. J. Munro, of Trinity College, Cambridge.

Lucretius had a very clear idea of the indestructibility of matter. He argues that things cannot have come out of nothing, and he says: “A thing never returns to nothing, but all things, after disruption, go back into the first bodies of matter.” He then argues that, as the actual processes of growth, decay, and other natural changes are imperceptible to us, therefore “Nature works by unseen bodies.” He justly claims great importance for the demonstration of the fact that in all matter whatever, however solid and hard it may be, there are vacancies, or, as he expresses it, “Mixed up in all things there is void or empty space.” He thus anticipated the modern doctrine that the molecules of matter do not come into actual contact. He then defines atoms thus: “First bodies are solid and without void”; and as nothing can be produced from nothing, he concludes that these first bodies (atoms or molecules) must be everlasting, and that they supply matter for the reproduction of all things.

He then goes on to prove that these “first beginnings are of solid singleness, not formed of parts, but strong in everlasting singleness.” He further proves that these “first beginnings” (atoms) cannot be infinitely small, and also that the universe cannot be limited—that it is infinite. He thus anticipated the main ideas as to atoms and the universe which have been held by most materialistic thinkers down to our own times.

Lucretius was an absolute materialist, for though he did not deny the existence of the gods he refused them any share in the construction of the universe, which, he again and again urges, arose by chance, after infinite time, by the random motions and collisions and entanglements of the infinity of atoms. He assumes some forces analogous to gravitation and the molecular motions of gases in the following passage: “For the first beginnings of things move first of themselves; next these bodies which form a small aggregate and come nearest, so to say, to the powers of the first beginnings are impelled and set in movement by the unseen strokes of these first bodies, and they next in turn stir up other bodies which are a little larger.”

He also anticipated Galileo as to the equal speed of all falling bodies when not checked by the air in the following precise statement: “For whenever bodies fall through water and thin air they must quicken their descents in proportion to their weights, because the body of water and subtle nature of air cannot retard everything to an equal degree; on the other hand, empty void cannot offer resistance to anything in any direction at any time, but must continually give way; and for this reason all things must be moved and borne along with equal velocity, though of unequal weights, through the unresisting void.”

This is a wonderfully accurate general statement of the equal rate of motion of all kinds of matter under the same forces; and when we consider that there is no indication of any experimental basis for this conclusion, and that nothing equivalent to our sciences of physics or chemistry existed, we are amazed at the general correctness of many of his views, derived solely by a process of reasoning from the most obvious phenomena of nature. He argues that, given infinite matter and space and inherent motion, “things must go on and be completed,” and his general conclusion is thus expressed: “If you will apprehend and keep in mind these things, nature, free at once and rid of her haughty lords, is seen to do all things spontaneously of herself without the meddling of the gods.”

It is when he attempts to deal with the origin of living organisms that the absence of all knowledge of chemistry, physiology, and histology renders his task impossible and leads him into what seem to us the wildest absurdities. He has an elaborate but very unconvincing argument that sensation can arise out of atoms which have no sensation; and, taking the appearance of worms, etc., in the earth and in putrid matter as a proof that they are still actually produced _de novo_ in it, he argues that at some remote epoch the now worn-out earth was more fertile, and produced in like manner all kinds of animals. The first human infants he supposes to have been formed at some very remote time in the manner following: “For much heat and moisture would then abound in the fields; and therefore wherever a suitable spot offered wombs would grow, attached to the earth by roots; and when the warmth of the infants, flying the wet and craving the air, had opened these in the fulness of time, nature would turn to that spot the pores of the earth and constrain it to yield from its opened veins a liquid most like to milk. To the children the earth would furnish food, the heat raiment, the grass a bed rich in abundance of soft down.... Wherefore, again and again I say, the earth, with good title, has gotten and keeps the name of mother, since she of herself gave birth to mankind, and at a time nearly fixed shed forth every beast that ranges wildly over the great mountains, and at the same time the fowls of the air with all their varied shapes.”

The fact that this mode of origin commended itself to one of the brightest intellects of the first century B. C., enlightened by the best thought of the Grecian philosophers, may enable us the better to appreciate the immense advance made by modern evolutionists.

THE FIRST REAL STEPS TOWARDS EVOLUTION

We have now a great blank of fifteen centuries—the dark ages of human progress—after which the era of observation and experiment began, and for the first time men really set themselves to study nature, thus laying the foundation for all the great theoretical advances of our time. As leading to the next great step in theories of evolution, we must note the life-long observations by Tycho Brahe of the apparent motions of the planets; the grand discovery of Kepler that all these apparently erratic motions were due to their revolution round the sun in elliptic orbits, with a fixed relation between their distance from the sun and their periods of revolution; and Newton’s epoch-making theory of universal gravitation by which all these facts and many others since discovered were harmonized and explained.

But all this implied no law of development, and it was long thought that the solar system was fixed and unchangeable—that some altogether unknown or miraculous agency must have set it going, and that it had in itself no principle of change or decay, but might continue as it now is to all eternity. It was at the very end of the eighteenth century that Laplace announced his “Nebular Hypothesis,” the first attempt ever made to explain the origin of the solar system under the influence of the known laws of motion, gravitation, and heat, acting upon an altogether different antecedent condition of things—a true process of evolution.

Laplace supposed that the whole matter of the solar system was once in a condition of vapor, and that it formed an enormous nebulous mass many times larger than the then known dimensions of the planetary sphere. He showed how, under the influence of gravitation, this nebula would condense, and that such irregularities of motion and density as would be sure to exist would lead to rotation of the mass. Under the law of gravitation this would lead to outer rings being left behind by the contraction of the central mass, which rings would at a later period become drawn together at some point of initial greater density and thus form planets. The whole process is admitted to be mathematically demonstrable, given the initial conditions; but recent extensions of our knowledge of the interplanetary and interstellar spaces have shown that the supposed void is really full of invisible solid matter, ranging from the bulk of the smaller planets down to the finest dust, and it is very difficult to imagine any possible causes which would keep all the solid matter of the system in a state of vapor, when subject, on the confines of the mass, to the cold of interstellar space. The antecedent condition of our system is now thought to have been either wholly or partially meteoritic, but in either case we have a genuine theory of its evolution which has now been so extended as to include the appearance of comets and meteors, of nebulæ, and star clusters, of temporary, periodic, and colored stars, and many other phenomena of the stellar universe. It is no objection to these grand theories to urge that they do not explain the origin of the matter of the universe, either what it is or how it came to be where we now find it. We can only take one step at a time, and even if in these greater problems any further advance should be as yet denied us, it is still a great thing to have been able to take even one secure step into the vast and mysterious depths of the interstellar spaces.

EVOLUTION OF THE EARTH’S CRUST

Although Pythagoras (500 B. C.) believed that sea and land must often have changed places, and a few other observers at different epochs came to the same conclusion, yet, till quite recent times, the earth was generally supposed to have been always very much as it is now; people spoke of “the eternal hills”; and the great mountain ranges, the mighty ravines and precipices, as well as the deep seas and oceans, were believed to be the direct work of the Creator.

It was only in the latter half of the eighteenth century that a few observers began to see the importance of studying the nature of the earth’s crust, so far as it could be reached in ravines, quarries, and mines; and one of the most earnest of these students, Dr. Hutton, of Edinburgh, after more than thirty years of travel and study, published his great work, _The Theory of the Earth_, which must be considered to be the starting-point of modern geology. He maintained that it was only by observing causes now in action that we can explain the phenomena presented by the stratified and igneous rocks; he showed that the former must have been laid down by water, and that the larger part of them, containing as they do marine shells and other fossils, must have been deposited on the sea-bottom. He showed how rain and rivers, frost and snow, wind and heat disintegrated the hardest rocks and would in time excavate the deepest valleys; while earthquakes, however small an elevation any one of them might produce, would in time raise the sea-bottom sufficiently high to form, when denuded, mountain ranges, plains, and valleys like those we now see everywhere upon the earth’s surface. He also showed that the most ancient stratified rocks, those that lie at the very base of the series, presented every indication of having been formed in exactly the same way as the most recent ones. Hence he stated a conclusion which excited a storm of opposition, in these words: “In the economy of the world I can find no traces of a beginning, no prospect of an end.” This was thought to imply a denial of creation, and was quite sufficient at that period to prevent the work of any man of science from being judged impartially.

But although Playfair and a few others upheld Hutton’s views, they were too novel to receive much support by his contemporaries, and this was especially the case as regards the slow and continuous action of existing causes being sufficient to account for all the known phenomena presented by the crust of the earth. Hence the belief in catastrophes and cataclysms—in great convulsions tearing mountains asunder, and vast floods sweeping over whole continents—continued to prevail, till finally banished by the genius and perseverance of one man, Sir Charles Lyell. His _Principles of Geology_ was first published in 1830, and successive editions, revised and often greatly extended, continued to appear till the author’s death, forty-five years later. As this work affords a fine example of the application of the principles of evolution to the later phases of the earth’s history, and as it not only revolutionized scientific opinion in its own domain, but prepared the way for the acceptance of the still more novel and startling application of the same principles to the entire organic world, it will be necessary to show what opinions prevailed at the time it first appeared in order that we may understand how great was the change it effected.

In the earlier years of the nineteenth century the standard geological work, both in Great Britain and on the Continent, was Cuvier’s _Essay on the Theory of the Earth_. In 1827 a fifth edition of the English translation appeared, and there was a German translation so late as 1830—sufficient proofs of its wide popularity. Yet this work abounds in statements which are positively ludicrous to any one conversant with modern geology. It never appeals to known causes, but again and again assumes forces to be at work for which no evidence is adduced and which are totally at variance with what we see in the world to-day. A few examples justifying these statements must be here given. Cuvier shows that he was acquainted with the theory of modern causes, but he altogether rejects it, saying that “the march of nature is changed, and none of the agents she now employs would have been sufficient for the production of her ancient works.” He adduces “the primitive mountains” whose “sharp and bristling ridges and peaks are indications of the violent manner in which they have been elevated.” He allows that atmospheric agencies may form sea-cliffs, alluvial deposits, and taluses of loose matter at the foot of the precipices, but he adds: “These are but limited effects to which vegetation in general puts a stop, and which, besides, presuppose the existence of mountains, valleys, and plains—in short, all the inequalities of the globe—and which, therefore, cannot have given rise to those inequalities.” He contrasts the calm and peaceful aspect of the surface of the earth with the appearances discovered when we examine its interior. Here, in the raised beds of shells, the fractured rocks, the inclined or even vertical stratification, he finds abundant proofs “that the surface of the globe has been broken up by revolutions and catastrophes.”