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THE
BREATH OF LIFE
BY
JOHN BURROUGHS
BOSTON AND NEW YORK HOUGHTON MIFFLIN COMPANY The Riverside Press Cambridge
COPYRIGHT, 1915, BY JOHN BURROUGHS
ALL RIGHTS RESERVED
Published May 1915
PREFACE
As life nears its end with me, I find myself meditating more and more upon the mystery of its nature and origin, yet without the least hope that I can find out the ways of the Eternal in this or in any other world. In these studies I fancy I am about as far from mastering the mystery as the ant which I saw this morning industriously exploring a small section of the garden walk is from getting a clear idea of the geography of the North American Continent. But the ant was occupied and was apparently happy, and she must have learned something about a small fraction of that part of the earth's surface.
I have passed many pleasant summer days in my hay-barn study, or under the apple trees, exploring these questions, and though I have not solved them, I am satisfied with the clearer view I have given myself of the mystery that envelops them. I have set down in these pages all the thoughts that have come to me on this subject. I have not aimed so much at consistency as at clearness and definiteness of statement, letting my mind drift as upon a shoreless sea. Indeed, what are such questions, and all other ultimate questions, but shoreless seas whereon the chief reward of the navigator is the joy of the adventure?
Sir Thomas Browne said, over two hundred years ago, that in philosophy truth seemed double-faced, by which I fancy he meant that there was always more than one point of view of all great problems, often contradictory points of view, from which truth is revealed. In the following pages I am aware that two ideas, or principles, struggle in my mind for mastery. One is the idea of the super-mechanical and the super-chemical character of living things; the other is the idea of the supremacy and universality of what we call natural law. The first probably springs from my inborn idealism and literary habit of mind; the second from my love of nature and my scientific bent. It is hard for me to reduce the life impulse to a level with common material forces that shape and control the world of inert matter, and it is equally hard for me to reconcile my reason to the introduction of a new principle, or to see anything in natural processes that savors of the ab-extra. It is the working of these two different ideas in my mind that seems to give rise to the obvious contradictions that crop out here and there throughout this volume. An explanation of life phenomena that savors of the laboratory and chemism repels me, and an explanation that savors of the theological point of view is equally distasteful to me. I crave and seek a natural explanation of all phenomena upon this earth, but the word "natural" to me implies more than mere chemistry and physics. The birth of a baby, and the blooming of a flower, are natural events, but the laboratory methods forever fail to give us the key to the secret of either.
I am forced to conclude that my passion for nature and for all open-air life, though tinged and stimulated by science, is not a passion for pure science, but for literature and philosophy. My imagination and ingrained humanism are appealed to by the facts and methods of natural history. I find something akin to poetry and religion (using the latter word in its non-mythological sense, as indicating the sum of mystery and reverence we feel in the presence of the great facts of life and death) in the shows of day and night, and in my excursions to fields and woods. The love of nature is a different thing from the love of science, though the two may go together. The Wordsworthian sense in nature, of "something far more deeply interfused" than the principles of exact science, is probably the source of nearly if not quite all that this volume holds. To the rigid man of science this is frank mysticism; but without a sense of the unknown and unknowable, life is flat and barren. Without the emotion of the beautiful, the sublime, the mysterious, there is no art, no religion, no literature. How to get from the clod underfoot to the brain and consciousness of man without invoking something outside of, and superior to, natural laws, is the question. For my own part I content myself with the thought of some unknown and doubtless unknowable tendency or power in the elements themselves—a kind of universal mind pervading living matter and the reason of its living, through which the whole drama of evolution is brought about.
This is getting very near to the old teleological conception, as it is also near to that of Henri Bergson and Sir Oliver Lodge. Our minds easily slide into the groove of supernaturalism and spiritualism because they have long moved therein. We have the words and they mould our thoughts. But science is fast teaching us that the universe is complete in itself; that whatever takes place in matter is by virtue of the force of matter; that it does not defer to or borrow from some other universe; that there is deep beneath deep in it; that gross matter has its interior in the molecule, and the molecule has its interior in the atom, and the atom has its interior in the electron, and that the electron is matter in its fourth or non-material state—the point where it touches the super-material. The transformation of physical energy into vital, and of vital into mental, doubtless takes place in this invisible inner world of atoms and electrons. The electric constitution of matter is a deduction of physics. It seems in some degree to bridge over the chasm between what we call the material and the spiritual. If we are not within hailing distance of life and mind, we seem assuredly on the road thither. The mystery of the transformation of the ethereal, imponderable forces into the vital and the mental seems quite beyond the power of the mind to solve. The explanation of it in the bald terms of chemistry and physics can never satisfy a mind with a trace of idealism in it.
The greater number of the chapters of this volume are variations upon a single theme,—what Tyndall called "the mystery and the miracle of vitality,"—and I can only hope that the variations are of sufficient interest to justify the inevitable repetitions which occur. I am no more inclined than Tyndall was to believe in miracles unless we name everything a miracle, while at the same time I am deeply impressed with the inadequacy of all known material forces to account for the phenomena of living things.
That word of evil repute, materialism, is no longer the black sheep in the flock that it was before the advent of modern transcendental physics. The spiritualized materialism of men like Huxley and Tyndall need not trouble us. It springs from the new conception of matter. It stands on the threshold of idealism or mysticism with the door ajar. After Tyndall had cast out the term "vital force," and reduced all visible phenomena of life to mechanical attraction and repulsion, after he had exhausted physics, and reached its very rim, a mighty mystery still hovered beyond him. He recognized that he had made no step toward its solution, and was forced to confess with the philosophers of all ages that
"We are such stuff As dreams are made on, and our little life Is rounded with a sleep."
CONTENTS
I. THE BREATH OF LIFE 1
II. THE LIVING WAVE 24
III. A WONDERFUL WORLD 46
IV. THE BAFFLING PROBLEM 71
V. SCIENTIFIC VITALISM 104
VI. A BIRD OF PASSAGE 115
VII. LIFE AND MIND 131
VIII. LIFE AND SCIENCE 159
IX. THE JOURNEYING ATOMS 188
X. THE VITAL ORDER 212
XI. THE ARRIVAL OF THE FIT 244
XII. THE NATURALIST'S VIEW OF LIFE 254
INDEX 291
The reproduction of the bust of Mr. Burroughs which appears as the frontispiece to this volume is used by courtesy of the sculptor, C. S. Pietro.
I
THE BREATH OF LIFE
I
When for the third or fourth time during the spring or summer I take my hoe and go out and cut off the heads of the lusty burdocks that send out their broad leaves along the edge of my garden or lawn, I often ask myself, "What is this thing that is so hard to scotch here in the grass?" I decapitate it time after time and yet it forthwith gets itself another head. We call it burdock, but what is burdock, and why does it not change into yellow dock, or into a cabbage? What is it that is so constant and so irrepressible, and before the summer is ended will be lying in wait here with its ten thousand little hooks to attach itself to every skirt or bushy tail or furry or woolly coat that comes along, in order to get free transportation to other lawns and gardens, to green fields and pastures new?
It is some living thing; but what is a living thing, and how does it differ from a mechanical and non-living thing? If I smash or overturn the sundial with my hoe, or break the hoe itself, these things stay smashed and broken, but the burdock mends itself, renews itself, and, if I am not on my guard, will surreptitiously mature some of the burs before the season is passed.
Evidently a living thing is radically different from a mechanical thing; yet modern physical science tells me that the burdock is only another kind of machine, and manifests nothing but the activity of the mechanical and chemical principles that we see in operation all about us in dead matter; and that a little different mechanical arrangement of its ultimate atoms would turn it into a yellow dock or into a cabbage, into an oak or into a pine, into an ox or into a man.
I see that it is a machine in this respect, that it is set going by a force exterior to itself—the warmth of the sun acting upon it, and upon the moisture in the soil; but it is unmechanical in that it repairs itself and grows and reproduces itself, and after it has ceased running can never be made to run again. After I have reduced all its activities to mechanical and chemical principles, my mind seems to see something that chemistry and mechanics do not explain—something that avails itself of these forces, but is not of them. This may be only my anthropomorphic way of looking at things, but are not all our ways of looking at things anthropomorphic? How can they be any other? They cannot be deific since we are not gods. They may be scientific. But what is science but a kind of anthropomorphism? Kant wisely said, "It sounds at first singular, but is none the less certain, that the understanding does not derive its laws from nature, but prescribes them to nature." This is the anthropomorphism of science.
If I attribute the phenomenon of life to a vital force or principle, am I any more unscientific than I am when I give a local habitation and a name to any other causal force, as gravity, chemical affinity, cohesion, osmosis, electricity, and so forth? These terms stand for certain special activities in nature and are as much the inventions of our own minds as are any of the rest of our ideas.
We can help ourselves out, as Haeckel does, by calling the physical forces—such as the magnet that attracts the iron filings, the powder that explodes, the steam that drives the locomotive, and the like—"living inorganics," and looking upon them as acting by "living force as much as the sensitive mimosa does when it contracts its leaves at touch." But living force is what we are trying to differentiate from mechanical force, and what do we gain by confounding the two? We can only look upon a living body as a machine by forming new conceptions of a machine—a machine utterly unmechanical, which is a contradiction of terms.
A man may expend the same kind of force in thinking that he expends in chopping his wood, but that fact does not put the two kinds of activity on the same level. There is no question but that the food consumed is the source of the energy in both cases, but in the one the energy is muscular, and in the other it is nervous. When we speak of mental or spiritual force, we have as distinct a conception as when we speak of physical force. It requires physical force to produce the effect that we call mental force, though how the one can result in the other is past understanding. The law of the correlation and conservation of energy requires that what goes into the body as physical force must come out in some form of physical force—heat, light, electricity, and so forth.
Science cannot trace force into the mental realm and connect it with our states of consciousness. It loses track of it so completely that men like Tyndall and Huxley and Spencer pause before it as an inscrutable mystery, while John Fiske helps himself out with the conception of the soul as quite independent of the body, standing related to it as the musician is related to his instrument. This idea is the key to Fiske's proof of the immortality of the soul. Finding himself face to face with an insoluble mystery, he cuts the knot, or rather, clears the chasm, by this extra-scientific leap. Since the soul, as we know it, is inseparably bound up with physical conditions, it seems to me that a more rational explanation of the phenomenon of mentality is the conception that the physical force and substance that we use up in a mental effort or emotional experience gives rise, through some unknown kind of molecular activity, to something which is analogous to the electric current in a live wire, and which traverses the nerves and results in our changing states of consciousness. This is the mechanistic explanation of mind, consciousness, etc., but it is the only one, or kind of one, that lends itself to scientific interpretation. Life, spirit, consciousness, may be a mode of motion as distinct from all other modes of motion, such as heat, light, electricity, as these are distinct from each other.
When we speak of force of mind, force of character, we of course speak in parables, since the force here alluded to is an experience of our own minds entirely and would not suffice to move the finest dust-particle in the air.
There could be no vegetable or animal life without the sunbeam, yet when we have explained or accounted for the growth of a tree in terms of the chemistry and physics of the sunbeam, do we not have to figure to ourselves something in the tree that avails itself of this chemistry, that uses it and profits by it? After this mysterious something has ceased to operate, or play its part, the chemistry of the sunbeam is no longer effective, and the tree is dead.
Without the vibrations that we call light, there would have been no eye. But, as Bergson happily says, it is not light passively received that makes the eye; it is light meeting an indwelling need in the organism, which amounts to an active creative principle, that begets the eye. With fish in underground waters this need does not arise; hence they have no sight. Fins and wings and legs are developed to meet some end of the organism, but if the organism were not charged with an expansive or developing force or impulse, would those needs arise?
Why should the vertebrate series have risen through the fish, the reptile, the mammal, to man, unless the manward impulse was inherent in the first vertebrate; something that struggled, that pushed on and up from the more simple to the more complex forms? Why did not unicellular life always remain unicellular? Could not the environment have acted upon it endlessly without causing it to change toward higher and more complex forms, had there not been some indwelling aboriginal tendency toward these forms? How could natural selection, or any other process of selection, work upon species to modify them, if there were not something in species pushing out and on, seeking new ways, new forms, in fact some active principle that is modifiable?
Life has risen by stepping-stones of its dead self to higher things. Why has it risen? Why did it not keep on the same level, and go through the cycle of change, as the inorganic does, without attaining to higher forms? Because, it may be replied, it was life, and not mere matter and motion—something that lifts matter and motion to a new plane.
Under the influence of the life impulse, the old routine of matter—from compound to compound, from solid to fluid, from fluid to gaseous, from rock to soil, the cycle always ending where it began—is broken into, and cycles of a new order are instituted. From the stable equilibrium which dead matter is always seeking, the same matter in the vital circuit is always seeking the state of unstable equilibrium, or rather is forever passing between the two, and evolving the myriad forms of life in the passage. It is hard to think of the process as the work of the physical and chemical forces of inorganic nature, without supplementing them with a new and different force.
The forces of life are constructive forces, and they are operative in a world of destructive or disintegrating forces which oppose them and which they overcome. The physical and chemical forces of dead matter are at war with the forces of life, till life overcomes and uses them.
The mechanical forces go on repeating or dividing through the same cycles forever and ever, seeking a stable condition, but the vital force is inventive and creative and constantly breaks the repose that organic nature seeks to impose upon it.
External forces may modify a body, but they cannot develop it unless there is something in the body waiting to be developed, craving development, as it were. The warmth and moisture in the soil act alike upon the grains of sand and upon the seed-germs; the germ changes into something else, the sand does not. These agents liberate a force in the germ that is not in the grain of sand. The warmth of the brooding fowl does not spend itself upon mere passive, inert matter (unless there is a china egg in the nest), but upon matter straining upon its leash, and in a state of expectancy. We do not know how the activity of the molecules of the egg differs from the activity of the molecules of the pebble, under the influence of warmth, but we know there must be a difference between the interior movements of organized and unorganized matter.
Life lifts inert matter up into a thousand varied and beautiful forms and holds it there for a season,—holds it against gravity and chemical affinity, though you may say, if you please, not without their aid,—and then in due course lets go of it, or abandons it, and lets it fall back into the great sea of the inorganic. Its constant tendency is to fall back; indeed, in animal life it does fall back every moment; it rises on the one hand, serves its purpose of life, and falls back on the other. In going through the cycle of life the mineral elements experience some change that chemical analysis does not disclose—they are the more readily absorbed again by life. It is as if the elements had profited in some way under the tutelage of life. Their experience has been a unique and exceptional one. Only a small fraction of the sum total of the inert matter of the globe can have this experience. It must first go through the vegetable cycle before it can be taken up by the animal. The only things we can take directly from the inorganic world are water and air; and the function of water is largely a mechanical one, and the function of air a chemical one.
I think of the vital as flowing out of the physical, just as the psychical flows out of the vital, and just as the higher forms of animal life flow out of the lower. It is a far cry from man to the dumb brutes, and from the brutes to the vegetable world, and from the vegetable to inert matter; but the germ and start of each is in the series below it. The living came out of the not-living. If life is of physico-chemical origin, it is so by transformations and translations that physics cannot explain. The butterfly comes out of the grub, man came out of the brute, but, as Darwin says, "not by his own efforts," any more than the child becomes the man by its own efforts.
The push of life, of the evolutionary process, is back of all and in all. We can account for it all by saying the Creative Energy is immanent in matter, and this gives the mind something to take hold of.
II
According to the latest scientific views held on the question by such men as Professor Loeb, the appearance of life on the globe was a purely accidental circumstance. The proper elements just happened to come together at the right time in the right proportions and under the right conditions, and life was the result. It was an accident in the thermal history of the globe. Professor Loeb has lately published a volume of essays and addresses called "The Mechanistic Conception of Life," enforcing and illustrating this view. He makes war on what he terms the metaphysical conception of a "life-principle" as the key to the problem, and urges the scientific conception of the adequacy of mechanico-chemical forces. In his view, we are only chemical mechanisms; and all our activities, mental and physical alike, are only automatic responses to the play of the blind, material forces of external nature. All forms of life, with all their wonderful adaptations, are only the chance happenings of the blind gropings and clashings of dead matter: "We eat, drink, and reproduce [and, of course, think and speculate and write books on the problems of life], not because mankind has reached an agreement that this is desirable, but because, machine-like, we are compelled to do so!"
He reaches the conclusion that all our inner subjective life is amenable to physico-chemical analysis, because many cases of simple animal instinct and will can be explained on this basis—the basis of animal tropism. Certain animals creep or fly to the light, others to the dark, because they cannot help it. This is tropism. He believes that the origin of life can be traced to the same physico-chemical activities, because, in his laboratory experiments, he has been able to dispense with the male principle, and to fertilize the eggs of certain low forms of marine life by chemical compounds alone. "The problem of the beginning and end of individual life is physico-chemically clear"—much clearer than the first beginnings of life. All individual life begins with the egg, but where did we get the egg? When chemical synthesis will give us this, the problem is solved. We can analyze the material elements of an organism, but we cannot synthesize them and produce the least spark of living matter. That all forms of life have a mechanical and chemical basis is beyond question, but when we apply our analysis to them, life evaporates, vanishes, the vital processes cease. But apply the same analysis to inert matter, and only the form is changed.
Professor Loeb's artificially fathered embryo and starfish and sea-urchins soon die. If his chemism could only give him the mother-principle also! But it will not. The mother-principle is at the very foundations of the organic world, and defies all attempts of chemical synthesis to reproduce it.
It would be presumptive in the extreme for me to question Professor Loeb's scientific conclusions; he is one of the most eminent of living experimental biologists. I would only dissent from some of his philosophical conclusions. I dissent from his statement that only the mechanistic conception of life can throw light on the source of ethics. Is there any room for the moral law in a world of mechanical determinism? There is no ethics in the physical order, and if humanity is entirely in the grip of that order, where do moral obligations come in? A gun, a steam-engine, knows no ethics, and to the extent that we are compelled to do things, are we in the same category. Freedom of choice alone gives any validity to ethical consideration. I dissent from the idea to which he apparently holds, that biology is only applied physics and chemistry. Is not geology also applied physics and chemistry? Is it any more or any less? Yet what a world of difference between the two—between a rock and a tree, between a man and the soil he cultivates. Grant that the physical and the chemical forces are the same in both, yet they work to such different ends in each. In one case they are tending always to a deadlock, to the slumber of a static equilibrium; in the other they are ceaselessly striving to reach a state of dynamic activity—to build up a body that hangs forever between a state of integration and disintegration. What is it that determines this new mode and end of their activities?
In all his biological experimentation, Professor Loeb starts with living matter and, finding its processes capable of physico-chemical analysis, he hastens to the conclusion that its genesis is to be accounted for by the action and interaction of these principles alone.
In the inorganic world, everything is in its place through the operation of blind physical forces; because the place of a dead thing, its relation to the whole, is a matter of indifference. The rocks, the hills, the streams are in their place, but any other place would do as well. But in the organic world we strike another order—an order where the relation and subordination of parts is everything, and to speak of human existence as a "matter of chance" in the sense, let us say, that the forms and positions of inanimate bodies are matters of chance, is to confuse terms.
Organic evolution upon the earth shows steady and regular progression; as much so as the growth and development of a tree. If the evolutionary impulse fails on one line, it picks itself up and tries on another, it experiments endlessly like an inventor, but always improves on its last attempts. Chance would have kept things at a standstill; the principle of chance, give it time enough, must end where it began. Chance is a man lost in the woods; he never arrives; he wanders aimlessly. If evolution pursued a course equally fortuitous, would it not still be wandering in the wilderness of the chaotic nebulae?
III
A vastly different and much more stimulating view of life is given by Henri Bergson in his "Creative Evolution." Though based upon biological science, it is a philosophical rather than a scientific view, and appeals to our intuitional and imaginative nature more than to our constructive reason. M. Bergson interprets the phenomena of life in terms of spirit, rather than in terms of matter as does Professor Loeb. The word "creative" is the key-word to his view. Life is a creative impulse or current which arose in matter at a certain time and place, and flows through it from form to form, from generation to generation, augmenting in force as it advances. It is one with spirit, and is incessant creation; the whole organic world is filled, from bottom to top, with one tremendous effort. It was long ago felicitously stated by Whitman in his "Leaves of Grass," "Urge and urge, always the procreant urge of the world."
This conception of the nature and genesis of life is bound to be challenged by modern physical science, which, for the most part, sees in biology only a phase of physics; but the philosophic mind and the trained literary mind will find in "Creative Evolution" a treasure-house of inspiring ideas, and engaging forms of original artistic expression. As Mr. Balfour says, "M. Bergson's 'Evolution Creatrice' is not merely a philosophical treatise, it has all the charm and all the audacities of a work of art, and as such defies adequate reproduction."
It delivers us from the hard mechanical conception of determinism, or of a closed universe which, like a huge manufacturing plant, grinds out vegetables and animals, minds and spirits, as it grinds out rocks and soils, gases and fluids, and the inorganic compounds.
With M. Bergson, life is the flowing metamorphosis of the poets,—an unceasing becoming,—and evolution is a wave of creative energy overflowing through matter "upon which each visible organism rides during the short interval of time given it to live." In his view, matter is held in the iron grip of necessity, but life is freedom itself. "Before the evolution of life ... the portals of the future remain wide open. It is a creation that goes on forever in virtue of an initial movement. This movement constitutes the unity of the organized world—a prolific unity, of an infinite richness, superior to any that the intellect could dream of, for the intellect is only one of its aspects or products."
What a contrast to Herbert Spencer's view of life and evolution! "Life," says Spencer, "consists of inner action so adjusted as to balance outer action." True enough, no doubt, but not interesting. If the philosopher could tell us what it is that brings about the adjustment, and that profits by it, we should at once prick up our ears. Of course, it is life. But what is life? It is inner action so adjusted as to balance outer action!
A recent contemptuous critic of M. Bergson's book, Hugh S. R. Elliot, points out, as if he were triumphantly vindicating the physico-chemical theory of the nature and origin of life, what a complete machine a cabbage is for converting solar energy into chemical and vital energy—how it takes up the raw material from the soil by a chemical and mechanical process, how these are brought into contact with the light and air through the leaves, and thus the cabbage is built up. In like manner, a man is a machine for converting chemical energy derived from the food he eats into motion, and the like. As if M. Bergson, or any one else, would dispute these things! In the same way, a steam-engine is a machine for converting the energy latent in coal into motion and power; but what force lies back of the engine, and was active in the construction?
The final question of the cabbage and the man still remains—Where did you get them?
You assume vitality to start with—how did you get it? Did it arise spontaneously out of dead matter? Mechanical and chemical forces do all the work of the living body, but who or what controls and directs them, so that one compounding of the elements begets a cabbage, and another compounding of the same elements begets an oak—one mixture of them and we have a frog, another and we have a man? Is there not room here for something besides blind, indifferent forces? If we make the molecules themselves creative, then we are begging the question. The creative energy by any other name remains the same.
IV
If life itself is not a force or a form of energy, yet behold what energy it is capable of exerting! It seems to me that Sir Oliver Lodge is a little confusing when he says in a recent essay that "life does not exert force—not even the most microscopical force—and certainly does not supply energy." Sir Oliver is thinking of life as a distinct entity—something apart from the matter which it animates. But even in this case can we not say that the mainspring of the energy of living bodies is the life that is in them?
Apart from the force exerted by living animal bodies, see the force exerted by living plant bodies. I thought of the remark of Sir Oliver one day not long after reading it, while I was walking in a beech wood and noted how the sprouting beechnuts had sent their pale radicles down through the dry leaves upon which they were lying, often piercing two or three of them, and forcing their way down into the mingled soil and leaf-mould a couple of inches. Force was certainly expended in doing this, and if the life in the sprouting nut did not exert it or expend it, what did?
When I drive a peg into the ground with my axe or mallet, is the life in my arm any more strictly the source (the secondary source) of the energy expended than is the nut in this case? Of course, the sun is the primal source of the energy in both cases, and in all cases, but does not life exert the force, use it, bring it to bear, which it receives from the universal fount of energy?
Life cannot supply energy de novo, cannot create it out of nothing, but it can and must draw upon the store of energy in which the earth floats as in a sea. When this energy or force is manifest through a living body, we call it vital force; when it is manifest through a mechanical contrivance, we call it mechanical force; when it is developed by the action and reaction of chemical compounds, we call it chemical force; the same force in each case, but behaving so differently in the one case from what it does in the other that we come to think of it as a new and distinct entity. Now if Sir Oliver or any one else could tell us what force is, this difference between the vitalists and the mechanists might be reconciled.
Darwin measured the force of the downward growth of the radicle, such as I have alluded to, as one quarter of a pound, and its lateral pressure as much greater. We know that the roots of trees insert themselves into seams in the rocks, and force the parts asunder. This force is measurable and is often very great. Its seat seems to be in the soft, milky substance called the cambium layer under the bark. These minute cells when their force is combined may become regular rock-splitters.
One of the most remarkable exhibitions of plant force I ever saw was in a Western city where I observed a species of wild sunflower forcing its way up through the asphalt pavement; the folded and compressed leaves of the plant, like a man's fist, had pushed against the hard but flexible concrete till it had bulged up and then split, and let the irrepressible plant through. The force exerted must have been many pounds. I think it doubtful if the strongest man could have pushed his fist through such a resisting medium. If it was not life which exerted this force, what was it? Life activities are a kind of explosion, and the slow continued explosions of this growing plant rent the pavement as surely as powder would have done. It is doubtful if any cultivated plant could have overcome such odds. It required the force of the untamed hairy plant of the plains to accomplish this feat.
That life does not supply energy, that is, is not an independent source of energy, seems to me obvious enough, but that it does not manifest energy, use energy, or "exert force," is far from obvious. If a growing plant or tree does not exert force by reason of its growing, or by virtue of a specific kind of activity among its particles, which we name life, and which does not take place in a stone or in a bar of iron or in dead timber, then how can we say that any mechanical device or explosive compound exerts force? The steam-engine does not create force, neither does the exploding dynamite, but these things exert force. We have to think of the sum total of the force of the universe, as of matter itself, as a constant factor, that can neither be increased nor diminished. All activity, organic and inorganic, draws upon this force: the plant and tree, as well as the engine and the explosive—the winds, the tides, the animal, the vegetable alike. I can think of but one force, but of any number of manifestations of force, and of two distinct kinds of manifestations, the organic and the inorganic, or the vital and the physical,—the latter divisible into the chemical and the mechanical, the former made up of these two working in infinite complexity because drawn into new relations, and lifted to higher ends by this something we call life.
We think of something in the organic that lifts and moves and redistributes dead matter, and builds it up into the ten thousand new forms which it would never assume without this something; it lifts lime and iron and silica and potash and carbon, against gravity, up into trees and animal forms, not by a new force, but by an old force in the hands of a new agent.
The cattle move about the field, the drift boulders slowly creep down the slopes; there is no doubt that the final source of the force is in both cases the same; what we call gravity, a name for a mystery, is the form it takes in the case of the rocks, and what we call vitality, another name for a mystery, is the form it takes in the case of the cattle; without the solar and stellar energy, could there be any motion of either rock or beast?
Force is universal, it pervades all nature, one manifestation of it we call heat, another light, another electricity, another cohesion, chemical affinity, and so on. May not another manifestation of it be called life, differing from all the rest more radically than they differ from one another; bound up with all the rest and inseparable from them and identical with them only in its ultimate source in the Creative Energy that is immanent in the universe? I have to think of the Creative Energy as immanent in all matter, and the final source of all the transformations and transmutations we see in the organic and the inorganic worlds. The very nature of our minds compels us to postulate some power, or some principle, not as lying back of, but as active in, all the changing forms of life and nature, and their final source and cause.
The mind is satisfied when it finds a word that gives it a hold of a thing or a process, or when it can picture to itself just how the thing occurs. Thus, for instance, to account for the power generated by the rushing together of hydrogen and oxygen to produce water, we have to conceive of space between the atoms of these elements, and that the force generated comes from the immense velocity with which the infinitesimal atoms rush together across this infinitesimal space. It is quite possible that this is not the true explanation at all, but it satisfies the mind because it is an explanation in terms of mechanical forces that we know.
The solar energy goes into the atoms or corpuscles one thing, and it comes out another; it goes in as inorganic force, and it comes out as organic and psychic. The change or transformation takes place in those invisible laboratories of the infinitesimal atoms. It helps my mental processes to give that change a name—vitality—and to recognize it as a supra-mechanical force. Pasteur wanted a name for it and called it "dissymmetric force."
We are all made of one stuff undoubtedly, vegetable and animal, man and woman, dog and donkey, and the secret of the difference between us, and of the passing along of the difference from generation to generation with but slight variations, may be, so to speak, in the way the molecules and atoms of our bodies take hold of hands and perform their mystic dances in the inner temple of life. But one would like to know who or what pipes the tune and directs the figures of the dance.
In the case of the beechnuts, what is it that lies dormant in the substance of the nuts and becomes alive, under the influence of the warmth and moisture of spring, and puts out a radicle that pierces the dry leaves like an awl? The pebbles, though they contain the same chemical elements, do not become active and put out a radicle.
The chemico-physical explanation of the universe goes but a little way. These are the tools of the creative process, but they are not that process, nor its prime cause. Start the flame of life going, and the rest may be explained in terms of chemistry; start the human body developing, and physiological processes explain its growth; but why it becomes a man and not a monkey—what explains that?
II
THE LIVING WAVE
I
If one attempts to reach any rational conclusion on the question of the nature and origin of life on this planet, he soon finds himself in close quarters with two difficulties. He must either admit of a break in the course of nature and the introduction of a new principle, the vital principle, which, if he is a man of science, he finds it hard to do; or he must accept the theory of the physico-chemical origin of life, which, as a being with a soul, he finds it equally hard to do. In other words, he must either draw an arbitrary line between the inorganic and the organic when he knows that drawing arbitrary lines in nature, and fencing off one part from another, is an unscientific procedure, and one that often leads to bewildering contradictions; or he must look upon himself with all his high thoughts and aspirations, and upon all other manifestations of life, as merely a chance product of the blind mechanical and chemical action and interaction of the inorganic forces.
Either conclusion is distasteful. One does not like to think of himself as a chance hit of the irrational physical elements; neither does he feel at ease with the thought that he is the result of any break or discontinuity in natural law. He likes to see himself as vitally and inevitably related to the physical order as is the fruit to the tree that bore it, or the child to the mother that carried it in her womb, and yet, if only mechanical and chemical forces entered into his genesis, he does not feel himself well fathered and mothered.
One may evade the difficulty, as Helmholtz did, by regarding life as eternal—that it had no beginning in time; or, as some other German biologists have done, that the entire cosmos is alive and the earth a living organism.
If biogenesis is true, and always has been true,—no life without antecedent life,—then the question of a beginning is unthinkable. It is just as easy to think of a stick with only one end.
Such stanch materialists and mechanists as Haeckel and Verworn seem to have felt compelled, as a last resort, to postulate a psychic principle in nature, though of a low order. Haeckel says that most chemists and physicists will not hear a word about a "soul" in the atom. "In my opinion, however," he says, "in order to explain the simplest physical and chemical processes, we must necessarily assume a low order of psychical activity among the homogeneous particles of plasm, rising a very little above that of the crystal." In crystallization he sees a low degree of sensation and a little higher degree in the plasm.
Have we not in this rudimentary psychic principle which Haeckel ascribes to the atom a germ to start with that will ultimately give us the mind of man? With this spark, it seems to me, we can kindle a flame that will consume Haeckel's whole mechanical theory of creation. Physical science is clear that the non-living or inorganic world was before the living or organic world, but that the latter in some mysterious way lay folded in the former. Science has for many years been making desperate efforts to awaken this slumbering life in its laboratories, but has not yet succeeded, and probably never will succeed. Life without antecedent life seems a biological impossibility. The theory of spontaneous generation is rejected by the philosophical mind, because our experience tells us that everything has its antecedent, and that there is and can be no end to the causal sequences.
Spencer believes that the organic and inorganic fade into each other by insensible gradations—that no line can be drawn between them so that one can say, on this side is the organic, on that the inorganic. In other words, he says it is not necessary for us to think of an absolute commencement of organic life, or of a first organism—organic matter was not produced all at once, but was reached through steps or gradations. Yet it puzzles one to see how there can be any gradations or degrees between being and not being. Can there be any halfway house between something and nothing?
II
There is another way out of the difficulty that besets our rational faculties in their efforts to solve this question, and that is the audacious way of Henri Bergson in his "Creative Evolution." It is to deny any validity to the conclusion of our logical faculties upon this subject. Our intellect, Bergson says, cannot grasp the true nature of life, nor the meaning of the evolutionary movement. With the emphasis of italics he repeats that "the intellect is characterized by a natural inability to comprehend life." He says this in a good many pages and in a good many different ways; the idea is one of the main conclusions of his book. Our intuitions, our spiritual nature, according to this philosopher, are more en rapport with the secrets of the creative energy than are our intellectual faculties; the key to the problem is to be found here, rather than in the mechanics and chemistry of the latter. Our intellectual faculties can grasp the physical order because they are formed by a world of solids and fluids and give us the power to deal with them and act upon them. But they cannot grasp the nature and the meaning of the vital order.
"We treat the living like the lifeless, and think all reality, however fluid, under the form of the sharply defined solid. We are at ease only in the discontinuous, in the immobile, in the dead. Perceiving in an organism only parts external to parts, the understanding has the choice between two systems of explanation only: either to regard the infinitely complex (and thereby infinitely well contrived) organization as a fortuitous concatenation of atoms, or to relate it to the incomprehensible influence of an external force that has grouped its elements together."
"Everything is obscure in the idea of creation, if we think of things which are created and a thing which creates." If we follow the lead of our logical, scientific faculties, then, we shall all be mechanists and materialists. Science can make no other solution of the problem because it sees from the outside. But if we look from the inside, with the spirit or "with that faculty of seeing which is immanent in the faculty of acting," we shall escape from the bondage of the mechanistic view into the freedom of the larger truth of the ceaseless creative view; we shall see the unity of the creative impulse which is immanent in life and which, "passing through generations, links individuals with individuals, species with species, and makes of the whole series of the living one single immense wave flowing over matter."
I recall that Tyndall, who was as much poet as scientist, speaks of life as a wave "which at no two consecutive moments of its existence is composed of the same particles." In his more sober scientific mood Tyndall would doubtless have rejected M. Bergson's view of life, yet his image of the wave is very Bergsonian. But what different meanings the two writers aim to convey: Tyndall is thinking of the fact that a living body is constantly taking up new material on the one side and dropping dead or outworn material on the other. M. Bergson's mind is occupied with the thought of the primal push or impulsion of matter which travels through it as the force in the wave traverses the water. The wave embodies a force which lifts the water up in opposition to its tendency to seek and keep a level, and travels on, leaving the water behind. So does this something we call life break the deadlock of inert matter and lift it into a thousand curious and beautiful forms, and then, passing on, lets it fall back again into a state of dead equilibrium.
Tyndall was one of the most eloquent exponents of the materialistic theory of the origin of life, and were he living now would probably feel little or no sympathy with the Bergsonian view of a primordial life impulse. He found the key to all life phenomena in the hidden world of molecular attraction and repulsion. He says: "Molecular forces determine the form which the solar energy will assume. [What a world of mystery lies in that determinism of the hidden molecular forces!] In the separation of the carbon and oxygen this energy may be so conditioned as to result in one case in the formation of a cabbage and in another case in the formation of an oak. So also as regards the reunion of the carbon and the oxygen [in the animal organism] the molecular machinery through which the combining energy acts may in one case weave the texture of a frog, while in another it may weave the texture of a man."
But is not this molecular force itself a form of solar energy, and can it differ in kind from any other form of physical force? If molecular forces determine whether the solar energy shall weave a head of a cabbage or a head of a Plato or a Shakespeare, does it not meet all the requirements of our conception of creative will?
Tyndall thinks that a living man—Socrates, Aristotle, Goethe, Darwin, I suppose—could be produced directly from inorganic nature in the laboratory if (and note what a momentous "if" this is) we could put together the elements of such a man in the same relative positions as those which they occupy in his body, "with the selfsame forces and distribution of forces, the selfsame motions and distribution of motions." Do this and you have a St. Paul or a Luther or a Lincoln. Dr. Verworn said essentially the same thing in a lecture before one of our colleges while in this country a few years ago—easy enough to manufacture a living being of any order of intellect if you can reproduce in the laboratory his "internal and external vital conditions." (The italics are mine.) To produce those vital conditions is where the rub comes. Those vital conditions, as regards the minutest bit of protoplasm, science, with all her tremendous resources, has not yet been able to produce. The raising of Lazarus from the dead seems no more a miracle than evoking vital conditions in dead matter. External and internal vital conditions are no doubt inseparably correlated, and when we can produce them we shall have life. Life, says Verworn, is like fire, and "is a phenomenon of nature which appears as soon as the complex of its conditions is fulfilled." We can easily produce fire by mechanical and chemical means, but not life. Fire is a chemical process, it is rapid oxidation, and oxidation is a disintegrating process, while life is an integrating process, or a balance maintained between the two by what we call the vital force. Life is evidently a much higher form of molecular activity than combustion. The old Greek Heraclitus saw, and the modern scientist sees, very superficially in comparing the two.
I have no doubt that Huxley was right in his inference "that if the properties of matter result from the nature and disposition of its component molecules, then there is no intelligible ground for refusing to say that the properties of protoplasm result from the nature and disposition of its molecules." It is undoubtedly in that nature and disposition of the biological molecules that Tyndall's whole "mystery and miracle of vitality" is wrapped up. If we could only grasp what it is that transforms the molecule of dead matter into the living molecule! Pasteur called it "dissymmetric force," which is only a new name for the mystery. He believed there was an "irrefragable physical barrier between organic and inorganic nature"—that the molecules of an organism differed from those of a mineral, and for this difference he found a name.
III
There seems to have been of late years a marked reaction, even among men of science, from the mechanistic conception of life as held by the band of scientists to which I have referred. Something like a new vitalism is making headway both on the Continent and in Great Britain. Its exponents urge that biological problems "defy any attempt at a mechanical explanation." These men stand for the idea "of the creative individuality of organisms" and that the main factors in organic evolution cannot be accounted for by the forces already operative in the inorganic world.
There is, of course, a mathematical chance that in the endless changes and permutations of inert matter the four principal elements that make up a living body may fall or run together in just that order and number that the kindling of the flame of life requires, but it is a disquieting proposition. One atom too much or too little of any of them,—three of oxygen where two were required, or two of nitrogen where only one was wanted,—and the face of the world might have been vastly different. Not only did much depend on their coming together, but upon the order of their coming; they must unite in just such an order. Insinuate an atom or corpuscle of hydrogen or carbon at the wrong point in the ranks, and the trick is a failure. Is there any chance that they will hit upon a combination of things and forces that will make a machine—a watch, a gun, or even a row of pins?
When we regard all the phenomena of life and the spell it seems to put upon inert matter, so that it behaves so differently from the same matter before it is drawn into the life circuit, when we see how it lifts up a world of dead particles out of the soil against gravity into trees and animals; how it changes the face of the earth; how it comes and goes while matter stays; how it defies chemistry and physics to evoke it from the non-living; how its departure, or cessation, lets the matter fall back to the inorganic—when we consider these and others like them, we seem compelled to think of life as something, some force or principle in itself, as M. Bergson and Sir Oliver Lodge do, existing apart from the matter it animates.
Sir Oliver Lodge, famous physicist that he is, yet has a vein of mysticism and idealism in him which sometimes makes him recoil from the hard-and-fast interpretations of natural phenomena by physical science. Like M. Bergson, he sees in life some tendency or impetus which arose in matter at a definite time and place, "and which has continued to interact with and incarnate itself in matter ever since."
If a living body is a machine, then we behold a new kind of machine with new kinds of mechanical principles—a machine that repairs itself, that reproduces itself, a clock that winds itself up, an engine that stokes itself, a gun that aims itself, a machine that divides and makes two, two unite and make four, a million or more unite and make a man or a tree—a machine that is nine tenths water, a machine that feeds on other machines, a machine that grows stronger with use; in fact, a machine that does all sorts of unmechanical things and that no known combination of mechanical and chemical principles can reproduce—a vital machine. The idea of the vital as something different from and opposed to the mechanical must come in. Something had to be added to the mechanical and chemical to make the vital.
Spencer explains in terms of physics why an ox is larger than the sheep, but he throws no light upon the subject of the individuality of these animals—what it is that makes an ox an ox or a sheep a sheep. These animals are built up out of the same elements by the same processes, and they may both have had the same stem form in remote biologic time. If so, what made them diverge and develop into such totally different forms? After the living body is once launched many, if not all, of its operations and economies can be explained on principles of mechanics and chemistry, but the something that avails itself of these principles and develops an ox in the one case and a sheep in the other—what of that?
Spencer is forced into using the terms "amount of vital capital." How much more of it some men, some animals, some plants have than others! What is it? What did Spencer mean by it? This capital augments from youth to manhood, and then after a short or long state of equilibrium slowly declines to the vanishing-point.
Again, what a man does depends upon what he is, and what he is depends upon what he does. Structure determines function, and function reacts upon structure. This interaction goes on throughout life; cause and effect interchange or play into each other's hands. The more power we spend within limits the more power we have. This is another respect in which life is utterly unmechanical. A machine does not grow stronger by use as our muscles do; it does not store up or conserve the energy it expends. The gun is weaker by every ball it hurls; not so the baseball pitcher; he is made stronger up to the limit of his capacity for strength.
It is plain enough that all living beings are machines in this respect—they are kept going by the reactions between their interior and their exterior; these reactions are either mechanical, as in flying, swimming, walking, and involve gravitation, or they are chemical and assimilative, as in breathing and eating. To that extent all living things are machines—some force exterior to themselves must aid in keeping them going; there is no spontaneous or uncaused movement in them; and yet what a difference between a machine and a living thing!
True it is that a man cannot live and function without heat and oxygen, nor long without food, and yet his relation to his medium and environment is as radically different from that of the steam-engine as it is possible to express. His driving-wheel, the heart, acts in response to some stimulus as truly as does the piston of the engine, and the principles involved in circulation are all mechanical; and yet the main thing is not mechanical, but vital. Analyze the vital activities into principles of mechanics and of chemistry, if you will, yet there is something involved that is neither mechanical nor chemical, though it may be that only the imagination can grasp it.
The type that prints the book is set up and again distributed by a purely mechanical process, but that which the printed page signifies involves something not mechanical. The mechanical and chemical principles operative in men's bodies are all the same; the cell structure is the same, and yet behold the difference between men in size, in strength, in appearance, in temperament, in disposition, in capacities! All the processes of respiration, circulation, and nutrition in our bodies involve well-known mechanical principles, and the body is accurately described as a machine; and yet if there were not something in it that transcends mechanics and chemistry would you and I be here? A machine is the same whether it is in action or repose, but when a body ceases to function, it is not the same. It cannot be set going like a machine; the motor power has ceased to be. But if the life of the body were no more than the sum of the reactions existing between the body and the medium in which it lives, this were not so. A body lives as long as there is a proper renewal of the interior medium through exchanges with its environment.
Mechanical principles are operative in every part of the body—in the heart, in the arteries, in the limbs, in the joints, in the bowels, in the muscles; and chemical principles are operative in the lungs, in the stomach, in the liver, in the kidneys; but to all these things do we not have to add something that is not mechanical or chemical to make the man, to make the plant? A higher mechanics, a higher chemistry, if you prefer, a force, but a force differing in kind from the physical forces.
The forces of life are constructive forces, and work in a world of disintegrating or destructive forces which oppose them and which they overcome. The mechanical and the chemical forces of dead matter are the enemies of the forces of life till life overcomes and uses them; as much so as gravity, fire, frost, water are man's enemies till he has learned how to subdue and use them.
IV
It is a significant fact that the four chief elements which in various combinations make up living bodies are by their extreme mobility well suited to their purpose. Three of these are gaseous; only the carbon is a solid. This renders them facile and adaptive in the ever-changing conditions of organic evolution. The solid carbon forms the vessel in which the precious essence of life is carried. Without carbon we should evaporate or flow away and escape. Much of the oxygen and hydrogen enters into living bodies as water; nine tenths of the human body is water; a little nitrogen and a few mineral salts make up the rest. So that our life in its final elements is little more than a stream of water holding in solution carbonaceous and other matter and flowing, forever flowing, a stream of fluid and solid matter plus something else that scientific analysis cannot reach—some force or principle that combines and organizes these elements into the living body.
If a man could be reduced instantly into his constituent elements we should see a pail or two of turbid fluid that would flow down the bank and soon be lost in the soil. That which gives us our form and stability and prevents us from slowly spilling down the slope at all times is the mysterious vital principle or force which knits and marries these unstable elements together and raises up a mobile but more or less stable form out of the world of fluids. Venus rising from the sea is a symbol of the genesis of every living thing.
Inorganic matter seeks only rest. "Let me alone," it says; "do not break my slumbers." But as soon as life awakens in it, it says: "Give me room, get out of my way. Ceaseless activity, ceaseless change, a thousand new forms are what I crave." As soon as life enters matter, matter meets with a change of heart. It is lifted to another plane, the supermechanical plane; it behaves in a new way; its movements from being calculable become incalculable. A straight line has direction, that is mechanics; what direction has the circle? That is life, a change of direction every instant. An aeroplane is built entirely on mechanical principles, but something not so built has to sit in it and guide it; in fact, had to build it and adjust it to its end.
Mechanical forces seek an equilibrium or a state of rest. The whole inorganic world under the influence of gravity would flow as water flows, if it could, till it reached a state of absolute repose. But vital forces struggle against a state of repose, which to them means death. They are vital by virtue of their tendency to resist the repose of inert matter; chemical activity disintegrates a stone or other metal, but the decay of organized matter is different in kind; living organisms decompose it and resolve it into its original compounds.
Vital connections and mechanical connections differ in kind. You can treat mechanical principles mathematically, but can you treat life mathematically? Will your formulas and equations apply here? You can figure out the eclipses of the sun and moon for centuries to come, but who can figure out the eclipses of nations or the overthrow of parties or the failures of great men? And it is not simply because the problem is so vastly more complex; it is because you are in a world where mathematical principles do not apply. Mechanical forces will determine the place and shape of every particle of inert matter any number of years or centuries hence, but they will not determine the place and condition of matter imbued with the principle of life.
We can graft living matter, we can even graft a part of one animal's body into another animal's body, but the mechanical union which we bring about must be changed into vital union to be a success, the spirit of the body has to second our efforts. The same in grafting a tree or anything else: the mechanical union which we effect must become a vital union; and this will not take place without some degree of consanguinity, the live scion must be recognized and adapted by the stock in which we introduce it.
Living matter may be symbolized by a stream; it is ever and never the same; life is a constant becoming; our minds and our bodies are never the same at any two moments of time; life is ceaseless change.
No doubt it is between the stable and the unstable condition of the molecules of matter that life is born. The static condition to which all things tend is death. Matter in an unstable condition tends either to explode or to grow or to disintegrate. So that an explosion bears some analogy to life, only it is quickly over and the static state of the elements is restored. Life is an infinitely slower explosion, or a prolonged explosion, during which some matter of the organism is being constantly burned up, and thus returned to a state of inorganic repose, while new matter is taken in and kindled and consumed by the fires of life. One can visualize all this and make it tangible to the intellect. Get your fire of life started and all is easy, but how to start it is the rub. Get your explosive compound, and something must break the deadlock of the elements before it will explode. So in life, what is it that sets up this slow gentle explosion that makes the machinery of our vital economies go—that draws new matter into the vortex and casts the used-up material out—in short, that creates and keeps up the unstable condition, the seesaw upon which life depends? To enable the mind to grasp it we have to invent or posit some principle, call it the vital force, as so many have done and still do, or call it molecular force, as Tyndall does, or the power of God, as our orthodox brethren do, it matters not. We are on the border-land between the knowable and the unknowable, where the mind can take no further step. There is no life without carbon and oxygen, hydrogen and nitrogen, but there is a world of these elements without life. What must be added to them to set up the reaction we call life? Nothing that chemistry can disclose.
New tendencies and activities are set up among these elements, but the elements themselves are not changed; oxygen is still oxygen and carbon still carbon, yet behold the wonder of their new workmanship under the tutelage of life!
Life only appears when the stable passes into the unstable, yet this change takes place all about us in our laboratories, and no life appears. We can send an electric spark through a room full of oxygen and hydrogen gas, and with a tremendous explosion we have water—an element of life, but not life.
Some of the elements seem nearer life than others. Water is near life; heat, light, the colloid state are near life; osmosis, oxidation, chemical reactions are near life; the ashes of inorganic bodies are nearer life than the same minerals in the rocks and soil; but none of these things is life.
The chemical mixture of some of the elements gives us our high explosives—gunpowder, guncotton, and the like; their organic mixture gives a slower kind of explosive—bread, meat, milk, fruit, which, when acted upon by the vital forces of the body, yield the force that is the equivalent of the work the body does. But to combine them in the laboratory so as to produce the compounds out of which the body can extract force is impossible. We can make an unstable compound that will hurl a ton of iron ten miles, but not one that when exploded in the digestive tract of the human body will lift a hair.
We may follow life down to the ground, yes, under the ground, into the very roots of matter and motion, yea, beyond the roots, into the imaginary world of molecules and atoms, and their attractions and repulsions and not find its secret. Indeed, science—the new science—pursues matter to the vanishing-point, where it ceases to become matter and becomes pure force or spirit. What takes place in that imaginary world where ponderable matter ends and becomes disembodied force, and where the hypothetical atoms are no longer divisible, we may conjecture but may never know. We may fancy the infinitely little going through a cycle of evolution like that of the infinitely great, and solar systems developing and revolving inside of the ultimate atoms, but the Copernicus or the Laplace of the atomic astronomy has not yet appeared. The atom itself is an invention of science. To get the mystery of vitality reduced to the atom is getting it in very close quarters, but it is a very big mystery still. Just how the dead becomes alive, even in the atom, is mystery enough to stagger any scientific mind. It is not the volume of the change; it is the quality or kind. Chemistry and mechanics we have always known, and they always remain chemistry and mechanics. They go into our laboratories and through our devices chemistry and mechanics, and they come out chemistry and mechanics. They will never come out life, conjure with them as we will, and we can get no other result. We cannot inaugurate the mystic dance among the atoms that will give us the least throb of life.
The psychic arises out of the organic and the organic arises out of the inorganic, and the inorganic arises out of—what? The relation of each to the other is as intimate as that of the soul to the body; we cannot get between them even in thought, but the difference is one of kind and not of degree. The vital transcends the mechanical, and the psychic transcends the vital—is on another plane, and yet without the sun's energy there could be neither. Thus are things knit together; thus does one thing flow out of or bloom out of another. We date from the rocks, and the rocks date from the fiery nebulae, and the loom in which the texture of our lives was woven is the great loom of vital energy about us and in us; but what hand guided the shuttle and invented the pattern—who knows?
III
A WONDERFUL WORLD
I
Science recognizes a more fundamental world than that of matter. This is the electro-magnetic world which underlies the material world and which, as Professor Soddy says, probably completely embraces it, and has no mechanical analogy. To those accustomed only to the grosser ideas of matter and its motions, says the British scientist, this electro-magnetic world is as difficult to conceive of as it would be for us to walk upon air. Yet many times in our lives is this world in overwhelming evidence before us. During a thunderstorm we get an inkling of how fearfully and wonderfully the universe in which we live is made, and what energy and activity its apparent passivity and opacity mark. A flash of lightning out of a storm-cloud seems instantly to transform the whole passive universe into a terrible living power. This slow, opaque, indifferent matter about us and above us, going its silent or noisy round of mechanical and chemical change, ponderable, insensate, obstructive, slumbering in the rocks, quietly active in the soil, gently rustling in the trees, sweetly purling in the brooks, slowly, invisibly building and shaping our bodies—how could we ever dream that it held in leash such a terrible, ubiquitous, spectacular thing as this of the forked lightning? If we were to see and hear it for the first time, should we not think that the Judgment Day had really come? that the great seals of the Book of Fate were being broken?
What an awakening it is! what a revelation! what a fearfully dramatic actor suddenly leaps upon the stage! Had we been permitted to look behind the scenes, we could not have found him; he was not there, except potentially; he was born and equipped in a twinkling. One stride, and one word which shakes the house, and he is gone; gone as quickly as he came. Look behind the curtain and he is not there. He has vanished more completely than any stage ghost ever vanished—he has withdrawn into the innermost recesses of the atomic structure of matter, and is diffused through the clouds, to be called back again, as the elemental drama proceeds, as suddenly as before.
All matter is charged with electricity, either actual or potential; the sun is hot with it, and doubtless our own heart-beats, our own thinking brains, are intimately related to it; yet it is palpable and visible only in this sudden and extraordinary way. It defies our analysis, it defies our definitions; it is inscrutable and incomprehensible, yet it will do our errands, light our houses, cook our dinners, and pull our loads.
How humdrum and constant and prosaic the other forces—gravity, cohesion, chemical affinity, and capillary attraction—seem when compared with this force of forces, electricity! How deep and prolonged it slumbers at one time, how terribly active and threatening at another, bellowing through the heavens like an infuriated god seeking whom he may destroy!
The warring of the elements at such times is no figure of speech. What has so disturbed the peace in the electric equilibrium, as to make possible this sudden outburst, this steep incline in the stream of energy, this ethereal Niagara pouring from heaven to earth? Is a thunderstorm a display of the atomic energy of which the physicists speak, and which, were it available for our use, would do all the work of the world many times over?
How marvelous that the softest summer breeze, or the impalpable currents of the calmest day, can be torn asunder with such suddenness and violence, by the accumulated energy that slumbers in the imaginary atoms, as to give forth a sound like the rending of mountains or the detonations of earthquakes!
Electricity is the soul of matter. If Whitman's paradox is true, that the soul and body are one, in the same sense the scientific paradox is true: that matter and electricity are one, and both are doubtless a phase of the universal ether—a reality which can be described only in terms of the negation of matter. In a flash of lightning we see pure disembodied energy—probably that which is the main-spring of the universe. Modern science is more and more inclined to find the explanation of all vital phenomena in electrical stress and change. We know that an electric current will bring about chemical changes otherwise impracticable. Nerve force, if not a form of electricity, is probably inseparable from it. Chemical changes equivalent to the combustion of fuel and the corresponding amount of available energy released have not yet been achieved outside of the living body without great loss. The living body makes a short cut from fuel to energy, and this avoids the wasteful process of the engine. What part electricity plays in this process is, of course, only conjectural.
II
Our daily lives go on for the most part in two worlds, the world of mechanical transposition and the world of chemical transformations, but we are usually conscious only of the former. This is the visible, palpable world of motion and change that rushes and roars around us in the winds, the storms, the floods, the moving and falling bodies, and the whole panorama of our material civilization; the latter is the world of silent, invisible, unsleeping, and all-potent chemical reactions that take place all about us and is confined to the atoms and molecules of matter, as the former is confined to its visible aggregates.
Mechanical forces and chemical affinities rule our physical lives, and indirectly our psychic lives as well. When we come into the world and draw our first breath, mechanics and chemistry start us on our career. Breathing is a mechanical, or a mechanico-vital, act; the mechanical principle involved is the same as that involved in the working of a bellows, but the oxidation of the blood when the air enters the lungs is a chemical act, or a chemico-vital act. The air gives up a part of its oxygen, which goes into the arterial circulation, and its place is taken by carbonic-acid gas and watery vapor. The oxygen feeds and keeps going the flame of life, as literally as it feeds and keeps going the fires in our stoves and furnaces.
Hence our most constant and vital relation to the world without is a chemical one. We can go without food for some days, but we can exist without breathing only a few moments. Through these spongy lungs of ours we lay hold upon the outward world in the most intimate and constant way. Through them we are rooted to the air. The air is a mechanical mixture of two very unlike gases—nitrogen and oxygen; one very inert, the other very active. Nitrogen is like a cold-blooded, lethargic person—it combines with other substances very reluctantly and with but little energy. Oxygen is just its opposite in this respect: it gives itself freely; it is "Hail, fellow; well met!" with most substances, and it enters into co-partnership with them on such a large scale that it forms nearly one half of the material of the earth's crust. This invisible gas, this breath of air, through the magic of chemical combination, forms nearly half the substance of the solid rocks. Deprive it of its affinity for carbon, or substitute nitrogen or hydrogen in its place, and the air would quickly suffocate us. That changing of the dark venous blood in our lungs into the bright, red, arterial blood would instantly cease. Fancy the sensation of inhaling an odorless, non-poisonous atmosphere that would make one gasp for breath! We should be quickly poisoned by the waste of our own bodies. All things that live must have oxygen, and all things that burn must have oxygen. Oxygen does not burn, but it supports combustion.
And herein is one of the mysteries of chemistry again. This support which the oxygen gives is utterly unlike any support we are acquainted with in the world of mechanical forces. Oxygen supports combustion by combining chemically with carbon, and the evolution of heat and light is the result. And this is another mystery—this chemical union which takes place in the ultimate particles of matter and which is so radically different from a mechanical mixture. In a chemical union the atoms are not simply in juxtaposition; they are, so to speak, inside of one another—each has swallowed another and lost its identity, an impossible feat, surely, viewed in the light of our experiences with tangible bodies. In the visible, mechanical world no two bodies can occupy the same place at the same time, but apparently in chemistry they can and do. An atom of oxygen and one of carbon, or of hydrogen, unite and are lost in each other; it is a marriage wherein the two or three become one. In dealing with the molecules and atoms of matter we are in a world wherein the laws of solid bodies do not apply; friction is abolished, elasticity is perfect, and place and form play no part. We have escaped from matter as we know it, the solid, fluid, or gaseous forms, and are dealing with it in its fourth or ethereal estate. In breathing, the oxygen goes into the blood, not to stay there, but to unite with and bring away the waste of the system in the shape of carbon, and re-enter the air again as one of the elements of carbonic-acid gas, CO_{2}. Then the reverse process takes place in the vegetable world, the leaves breathe this poisonous gas, release the oxygen under the chemistry of the sun's rays, and appropriate and store up the carbon. Thus do the animal and vegetable worlds play into each other's hands. The animal is dependent upon the vegetable for its carbon, which it releases again, through the life processes, as carbonic-acid gas, to be again drawn into the cycle of vegetable life.
The act of breathing well illustrates our mysterious relations to Nature—the cunning way in which she plays the principal part in our lives without our knowledge. How certain we are that we draw the air into our lungs—that we seize hold of it in some way as if it were a continuous substance, and pull it into our bodies! Are we not also certain that the pump sucks the water up through the pipe, and that we suck our iced drinks through a straw? We are quite unconscious of the fact that the weight of the superincumbent air does it all, that breathing is only to a very limited extent a voluntary act. It is controlled by muscular machinery, but that machinery would not act in a vacuum. We contract the diaphragm, or the diaphragm contracts under stimuli received through the medulla oblongata from those parts of the body which constantly demand oxygen, and a vacuum tends to form in the chest, which is constantly prevented by the air rushing in to fill it. The expansive force of the air under its own weight causes the lungs to fill, just as it causes the bellows of the blacksmith to fill when he works the lever, and the water to rise in the pump when we force out the air by working the handle. Another unconscious muscular effort under the influence of nerve stimulus, and the air is forced out of the lungs, charged with the bodily waste which it is the function to relieve. But the wonder of it all is how slight a part our wills play in the process, and how our lives are kept going by a mechanical force from without, seconded or supplemented by chemical and vital forces from within.
The one chemical process with which we are familiar all our lives, but which we never think of as such, is fire. Here on our own hearthstones goes on this wonderful spectacular and beneficent transformation of matter and energy, and yet we are grown so familiar with it that it moves us not. We can describe combustion in terms of chemistry, just as we can describe the life-processes in similar terms, yet the mystery is no more cleared up in the one case than in the other. Indeed, it seems to me that next to the mystery of life is the mystery of fire. The oxidizing processes are identical, only one is a building up or integrating process, and the other is a pulling down or disintegrating process. More than that, we can evoke fire any time, by both mechanical and chemical means, from the combustible matter about us; but we cannot evoke life. The equivalents of life do not slumber in our tools as do the equivalents of fire. Hence life is the deeper mystery. The ancients thought of a spirit of fire as they did of a spirit of health and of disease, and of good and bad spirits all about them, and as we think of a spirit of life, or of a creative life principle. Are we as wide of the mark as they were? So think many earnest students of living things. When we do not have to pass the torch of life along, but can kindle it in our laboratories, then this charge will assume a different aspect.
III
Nature works with such simple means! A little more or a little less of this or that, and behold the difference! A little more or a little less heat, and the face of the world is changed.
"And the little more, and how much it is, And the little less, and what worlds away!"
At one temperature water is solid, at another it is fluid, at another it is a visible vapor, at a still higher it is an invisible vapor that burns like a flame. All possible shades of color lurk in a colorless ray of light. A little more or a little less heat makes all the difference between a nebula and a sun, and between a sun and a planet. At one degree of heat the elements are dissociated; at a lower degree they are united. At one point in the scale of temperatures life appears; at another it disappears. With heat enough the earth would melt like a snowball in a furnace, with still more it would become a vapor and float away like a cloud. More or less heat only makes the difference between the fluidity of water and the solidity of the rocks that it beats against, or of the banks that hold it.
The physical history of the universe is written in terms of heat and motion. Astronomy is the story of cooling suns and worlds. At a low enough temperature all chemical activity ceases. In our own experience we find that frost will blister like flame. In the one case heat passes into the tissues so quickly and in such quantity that a blister ensues; in the other, heat is abstracted so quickly and in such quantity that a like effect is produced. In one sense, life is a thermal phenomenon; so are all conditions of fluids and solids thermal phenomena.
Great wonders Nature seems to achieve by varying the arrangement of the same particles. Arrange or unite the atoms of carbon in one way and you have charcoal; assemble the same atoms in another order, and you have the diamond. The difference between the pearl and the oyster-shell that holds it is one of structure or arrangement of the same particles of matter. Arrange the atoms of silica in one way and you have a quartz pebble, in another way and you have a precious stone. The chemical constituents of alcohol and ether are the same; the difference in their qualities and properties arises from the way the elements are compounded—the way they take hold of hands, so to speak, in that marriage ceremony which constitutes a chemical compound. Compounds identical in composition and in molecular formulae may yet differ widely in physical properties; the elements are probably grouped in different ways, the atoms of carbon or of hydrogen probably carry different amounts of potential energy, so that the order in which they stand related to one another accounts for the different properties of the same chemical compounds. Different groupings of the same atoms of any of the elements result in a like difference of physical properties.
The physicists tell us that what we call the qualities of things, and their structure and composition, are but the expressions of internal atomic movements. A complex substance simply means a whirl, an intricate dance, of which chemical composition, histological structure, and gross configuration are the figures. How the atoms take hold of hands, as it were, the way they face, the poses they assume, the speed of their gyrations, the partners they exchange, determine the kinds of phenomena we are dealing with.
There is a striking analogy between the letters of our alphabet and their relation to the language of the vast volume of printed books, and the eighty or more primary elements and their relation to the vast universe of material things. The analogy may not be in all respects a strictly true one, but it is an illuminating one. Our twenty-six letters combined and repeated in different orders give us the many thousand words our language possesses, and these words combined and repeated in different orders give us the vast body of printed books in our libraries. The ultimate parts—the atoms and molecules of all literature, so to speak—are the letters of the alphabet. How often by changing a letter in a word, by reversing their order, or by substituting one letter for another, we get a word of an entirely different meaning, as in umpire and empire, petrifaction and putrefaction, malt and salt, tool and fool. And by changing the order of the words in a sentence we express all the infinite variety of ideas and meanings that the books of the world hold.
The eighty or more primordial elements are Nature's alphabet with which she writes her "infinite book of secrecy." Science shows pretty conclusively that the character of the different substances, their diverse qualities and properties, depend upon the order in which the atoms and molecules are combined. Change the order in which the molecules of the carbon and oxygen are combined in alcohol, and we get ether—the chemical formula remaining the same. Or take ordinary spirits of wine and add four more atoms of carbon to the carbon molecules, and we have the poison, carbolic acid. Pure alcohol is turned into a deadly poison by taking from it one atom of carbon and two of hydrogen. With the atoms of carbon, hydrogen, and oxygen, by combining them in different proportions and in different orders, Nature produces such diverse bodies as acetic acid, alcohol, sugar, starch, animal fats, vegetable oils, glycerine, and the like. So with the long list of hydrocarbons—gaseous, liquid, and solid—called paraffins, that are obtained from petroleum and that are all composed of hydrogen and carbon, but with a different number of atoms of each, like a different number of a's or b's or c's in a word.
What an enormous number of bodies Nature forms out of oxygen by uniting it chemically with other primary elements! Thus by uniting it with the element silica she forms half of the solid crust of the globe; by uniting it with hydrogen in the proportion of two to one she forms all the water of the globe. With one atom of nitrogen united chemically with three atoms of hydrogen she forms ammonia. With one atom of carbon united with four atoms of hydrogen she spells marsh gas; and so on. Carbon occurs in inorganic nature in two crystalline forms,—the diamond and black lead, or graphite,—their physical differences evidently being the result of their different molecular structure. Graphite is a good conductor of heat and electricity, and the diamond is not. Carbon in the organic world, where it plays such an important part, is non-crystalline. Under the influence of life its molecules are differently put together, as in sugar, starch, wood, charcoal, etc. There are also two forms of phosphorus, but not two kinds; the same atoms are probably united differently in each. The yellow waxy variety has such an affinity for oxygen that it will burn in water, and it is poisonous. Bring this variety to a high temperature away from the air, and its molecular structure seems to change, and we have the red variety, which is tasteless, odorless, and non-poisonous, and is not affected by contact with the air. Such is the mystery of chemical change.
IV
Science has developed methods and implements of incredible delicacy. Its "microbalance" can estimate "the difference of weight of the order of the millionth of a milligram." Light travels at the speed of 186,000 miles a second, yet science can follow it with its methods, and finds that it travels faster with the current of running water than against it. Science has perfected a thermal instrument by which it can detect the heat of a lighted candle six miles away, and the warmth of the human face several miles distant. It has devised a method by which it can count the particles in the alpha rays of radium that move at a velocity of twenty thousand kilometers a second, and a method by which, through the use of a screen of zinc-sulphide, it can see the flashes produced by the alpha atoms when they strike this screen. It weighs and counts and calculates the motions of particles of matter so infinitely small that only the imagination can grasp them. Its theories require it to treat the ultimate particles into which it resolves matter, and which are so small that they are no longer divisible, as if they were solid bodies with weight and form, with centre and circumference, colliding with one another like billiard-balls, or like cosmic bodies in the depths of space, striking one another squarely, and, for aught I know, each going through another, or else grazing one another and glancing off. To particles of matter so small that they can no longer be divided or made smaller, the impossible feat of each going through the centre of another, or of each enveloping the other, might be affirmed of them without adding to their unthinkableness. The theory is that if we divide a molecule of water the parts are no longer water, but atoms of hydrogen and oxygen—real bodies with weight and form, and storehouses of energy, but no longer divisible. |
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