Littell's Living Age

ural philosopher may be said to have con- | liquids and the behaviour of solids seem not

quered completely the realm of physics, and only different, but contrary: the solid body the chemical philosopher has made nearly not only has a definite shape, but preserves as complete a conquest of the realm of that shape, and resists with might and main chemistry. The natural philosopher finds any attempt to interfere with its form, its that the great law of gravitation rules the place, or its attitude. Another body, like phenomena of the material universe: armed quicksilver or water, runs, flows, can hardly with the weapons of mathematics, master be kept still save by the interference of conof the sciences of form, quantity, and num-trolling force. Who can say, then, there ber, he finds nowhere on the earth's surface is resemblance or unity in the phenomena a single particle of matter the motion and of running liquids and resisting solids ? general behaviour of which under all known There is another class of bodies, -the air circumstances he cannot predict. The path we breathe, the airs that suffocate, the hurof a cannon-ball through the air, of a steam-ricane that rouses the storm. Who will ship through the ocean, of a railway train say that airs are like liquids, that the wind across a chasm, are illustrations at once of which blows is like the wave it rouses, that the predictions of pure physical science and the breath of the zephyr is of the same of the rewards conferred upon those who matter as the leaves of the trees it causes to believe in it with a faith so implicit as to vibrate? Nevertheless, the oscillations of induce them to adopt the principles of sci- the storm in the air are the same as the ence into the ventures of practical life. oscillations of the wave it rouses, and the vibrations of the aspen leaf are modulated by the same law which propagates the gentle zephyr from place to place. The same cause working through the same means in the same way works out all these varying phenomena.

The triumphs of the modern mechanical arts are therefore the triumphs of modern physical science; and as facts of daily life they proclaim the universality of her laws. But these physical laws have been found to bear rule, equally inflexible and equally intelligible, in the phenomena of other worlds as in those of our own. Terrestrial physics and celestial physics differ in no single respect except in the scale of their operations. The pendulum swinging in the timepiece, the tide swinging round the earth, the earth But there is another region equally vast swinging round the sun, and the sun sweepthe domain of chemical science, which ing through the circle of the fixed stars, are was at the beginning of this century the all phenomena which differ only in the contrary of all this: where knowledge was largeness of the figures required to express ignorance, where universal difference reigned them; the adequate conception and ex- instead of sameness, and where still to a pression of one of them is equally the ade- vast extent the unknown may be said to quate conception and expression of all the predominate. Of chemistry the great charothers; a single particle of water in a sea-acteristic is that no one piece of matter is wave is a revolving planet, and in the infinity of the shining sands of the heavens we see but the regular motions of the atoms of the ocean of universal matter.

Thus then there is one vast region of our knowledge, the domain of physical science, where we have been able to determine that intelligence, order, and law reign undisputed and universal.

In physical science, therefore, all matter is one, and all matter is of one sort, and obeys but one law. Form, quantity, and number are the conditions which regulate the development and express the phases of that law, but in the visible phenomena of the material world we find infinite variety, which at first sight seems destructive of this unity and universality. The behaviour of

like any other piece of matter, that the things which surround us are all intrinsically different, that the matter of which a vegetable is made is not the same as that of which a crystal is made, and that, instead of there being one sort of matter following one universal law, there are thousands of sorts of matters following hundreds of different laws: so that, under exactly the same circumstances and under precisely identical influences, this piece of matter will exhibit one set of phenomena, and that quite another or even contrary set of phenomena.

The very essence of chemistry then is that ter, not by the same fixed measure, but by matter is of infinite variety, that the laws it the actual proportions which these bear to obeys are as various as the classes of mat- one another. On the outside of us, the ter they govern, and that prediction about telescope has realized the enormous dismatter is impossible until we have first set-tances which part planet from planet and tled the class of body to which it belongs. star from star, but it has not yet been able The chemist makes it his business to sub- to penetrate those vaster distances which divide infinitely the sorts of matter of the seem to create in infinite space starry paveworld, and to determine by actual experi- ments out of golden sand. In like manner ment in detail the distinctions and differ- the microscope has penetrated into the hidences of every variety. "Nature is one," den recesses of seemingly solid lumps of says the physical philosopher; Nature is matter, and has revealed to us that the apmultitudinous," says the chemical philoso-parently solid lump of wood or stone has pher. "Everything is alike," says the one; within it wide open spaces, of far larger Everything is different," says the other. area than the part of the substance which "All obey the same law," says the physicist; seems to be composed of solid matter. "Each class has a law for its kind," says Thus we have been led to the conviction the chemist: "In the same conditions all that in the minutest particle of iron or sand will do the same thing;" "In the same there intervene large spaces of vacant room conditions each will do a different thing." to which the hard matter, as it seems from Happy for the world that these two phil- the outside, is but a crust, a shell, or an osophies exist, and not one only. Had the open network. Thus the twofold irreconnatural philosopher only lived, we should cilability of nature without and nature withsoon have got to the end of nature knowl-in disappears under the strong will aided edge; had the chemical philosopher only lived, we should never have begun it.

by the strong intellect that refuses to recognise in universal nature contraries or opposites.

Thus, to common sense and reason, the region of physical science and the region Dalton's great doctrine was this: The of chemical science are worlds irreconcila- opposites you seem to see in matter are seemble; and, but for the aid of a few philoso- ing but not real: the changes of alchemy phers of broad views and deep thought, the under which new matter seems to grow or whole world might have remained in two to dissolve, under which new substances antagonistic divisions. Such men were seem to be created out of nothing, are but Dalton and Faraday. These champions of the play of colour and seeming, and the the unity of nature brought into the domain change in the outside of things. Chemisof philosophic discovery that deep innate try makes no new thing-dissolves no old conviction which is at the root of true phil- one; the atoms are always there, always osophy — that all truth is but one, and that the same, and only by you re-arranged. all nature is the offspring of concordant, not When out of two gases you seem to make discordant, thought. These men refused to one different from both, the new gas is but believe that the laws of chemistry were ex- the sum of the atoms of the old, and if you ceptions to the laws of physics-that one will apply the common test of gravity to all, law extended from the remotest regions of you will find that all the atoms of the one space down to the surface of the earth, and added to all the atoms of the other make yet that, when we went into the inside, into up the same sum as before; and although the matter of the earth, we should find that the two may not occupy more space than what is true for the outside is false for the one of them did before, you will find that inside. They persisted in believing, and in the atoms of the one have entered into the making good their belief, that in nature spaces between the other, and that the new there is no scale of great and little; that substance consists of a body of the same between the particles of a ball of clay there bulk as the old, but holding the substantial may be as much vacant space as between particles of the two. But sometimes the bodies of a planetary system, measuring in transformation is even greater in appearboth cases the space and the absolute mat-ance, though in reality the same.

A sub

ural philosopher may be said to have conquered completely the realm of physics, and the chemical philosopher has made nearly as complete a conquest of the realm of chemistry. The natural philosopher finds that the great law of gravitation rules the phenomena of the material universe: armed with the weapons of mathematics, master of the sciences of form, quantity, and number, he finds nowhere on the earth's surface a single particle of matter the motion and general behaviour of which under all known circumstances he cannot predict. The path of a cannon-ball through the air, of a steamship through the ocean, of a railway train across a chasm, are illustrations at once of the predictions of pure physical science and of the rewards conferred upon those who believe in it with a faith so implicit as to induce them to adopt the principles of science into the ventures of practical life.

liquids and the behaviour of solids seem not only different, but contrary: the solid body not only has a definite shape, but preserves that shape, and resists with might and main any attempt to interfere with its form, its place, or its attitude. Another body, like quicksilver or water, runs, flows, can hardly be kept still save by the interference of controlling force. Who can say, then, there is resemblance or unity in the phenomena of running liquids and resisting solids? There is another class of bodies, the air we breathe, the airs that suffocate, the hurricane that rouses the storm. Who will say that airs are like liquids, that the wind which blows is like the wave it rouses, that the breath of the zephyr is of the same matter as the leaves of the trees it causes to vibrate? Nevertheless, the oscillations of the storm in the air are the same as the oscillations of the wave it rouses, and the vibrations of the aspen leaf are modulated by the same law which propagates the gentle zephyr from place to place. The same cause working through the same means in the same way works out all these varying phenomena.

Thus then there is one vast region of our knowledge, the domain of physical science, where we have been able to determine that intelligence, order, and law reign undisputed and universal.

The triumphs of the modern mechanical arts are therefore the triumphs of modern physical science; and as facts of daily life they proclaim the universality of her laws. But these physical laws have been found to bear rule, equally inflexible and equally intelligible, in the phenomena of other worlds as in those of our own. Terrestrial physics and celestial physics differ in no single respect except in the scale of their operations. The pendulum swinging in the timepiece, the tide swinging round the earth, the earth But there is another region equally vast swinging round the sun, and the sun sweep-the domain of chemical science, which ing through the circle of the fixed stars, are was at the beginning of this century the all phenomena which differ only in the contrary of all this: where knowledge was largeness of the figures required to express ignorance, where universal difference reigned them; the adequate conception and ex- instead of sameness, and where still to a pression of one of them is equally the ade- vast extent the unknown may be said to quate conception and expression of all the predominate. Of chemistry the great charothers; a single particle of water in a sea-acteristic is that no one piece of matter is wave is a revolving planet, and in the infinity of the shining sands of the heavens we see but the regular motions of the atoms of the ocean of universal matter.

The very essence of chemistry then is that ter, not by the same fixed measure, but by matter is of infinite variety, that the laws it the actual proportions which these bear to obeys are as various as the classes of mat- one another. On the outside of us, the ter they govern, and that prediction about telescope has realized the enormous dismatter is impossible until we have first set- tances which part planet from planet and tled the class of body to which it belongs. star from star, but it has not yet been able The chemist makes it his business to sub- to penetrate those vaster distances which divide infinitely the sorts of matter of the seem to create in infinite space starry paveworld, and to determine by actual experiments out of golden sand. In like manner ment in detail the distinctions and differ- the microscope has penetrated into the hidences of every variety. "Nature is one," den recesses of seemingly solid lumps of says the physical philosopher; Nature is matter, and has revealed to us that the apmultitudinous," says the chemical philoso-parently solid lump of wood or stone has pher. "Everything is alike," says the one; within it wide open spaces, of far larger Everything is different," says the other. area than the part of the substance which "All obey the same law," says the physicist; seems to be composed of solid matter. "Each class has a law for its kind," says Thus we have been led to the conviction the chemist: "In the same conditions all that in the minutest particle of iron or sand will do the same thing;" "In the same there intervene large spaces of vacant room conditions each will do a different thing." to which the hard matter, as it seems from Happy for the world that these two phil- the outside, is but a crust, a shell, or an osophies exist, and not one only. Had the open network. Thus the twofold irreconnatural philosopher only lived, we should cilability of nature without and nature withsoon have got to the end of nature knowl-in disappears under the strong will aided edge; had the chemical philosopher only lived, we should never have begun it.

by the strong intellect that refuses to recognise in universal nature contraries or opposites.

Thus, to common sense and reason, the region of physical science and the region. Dalton's great doctrine was this: The of chemical science are worlds irreconcila- opposites you seem to see in matter are seemble; and, but for the aid of a few philoso- ing but not real: the changes of alchemy phers of broad views and deep thought, the under which new matter seems to grow or whole world might have remained in two to dissolve, under which new substances antagonistic divisions. Such men were seem to be created out of nothing, are but Dalton and Faraday. These champions of the play of colour and seeming, and the the unity of nature brought into the domain change in the outside of things. Chemisof philosophic discovery that deep innate try makes no new thing-dissolves no old conviction which is at the root of true phil- one; the atoms are always there, always osophy-that all truth is but one, and that the same, and only by you re-arranged. all nature is the offspring of concordant, not When out of two gases you seem to make discordant, thought. These men refused to one different from both, the new gas is but believe that the laws of chemistry were ex- the sum of the atoms of the old, and if you ceptions to the laws of physics—that one will apply the common test of gravity to all, law extended from the remotest regions of you will find that all the atoms of the one space down to the surface of the earth, and added to all the atoms of the other make yet that, when we went into the inside, into up the same sum as before; and although the matter of the earth, we should find that the two may not occupy more space than what is true for the outside is false for the one of them did before, you will find that inside. They persisted in believing, and in the atoms of the one have entered into the making good their belief, that in nature spaces between the other, and that the new there is no scale of great and little; that substance consists of a body of the same between the particles of a ball of clay there bulk as the old, but holding the substantial may be as much vacant space as between particles of the two. But sometimes the bodies of a planetary system, measuring in transformation is even greater in appearboth cases the space and the absolute mat-ance, though in reality the same. A sub

stance twice the bulk of another may have but in so doing he deprived her of originits particles poured into the vacant spaces ality and creative power. She no longer of that other, and there in each vacant makes new substances; she merely comspace a pair of new particles will lodge in pounds, adds, distributes, separates atoms the chamber along with its original tenant, of old ones; and the question arose in the and so there will be three tenants for the minds of philosophers whether the substanoriginal space; in that case the substance ces which chemistry calls different are subwhich seems a new one is merely the addi- stantially different, or only seem so. Are tion of two atoms of one to each atom of the half hundred substances which it calls the other; and this "three-atomic sub-metals really so many different kinds of stance" will testify to the presence of the matter, independent creations so radically additional matter by the fact that the distinct in nature that no one of them could weight in the same bulk is three times the be formed out of the matter of any one of previous weight. the others, nor out of the atoms of two, three, or more, in any possible combination? If so, then matter is not one, but multitudinous, and to create a world it would be necessary to find not one matter merely, but some fifty different matters. Then there are a dozen non-metallic elements: are these in substance radically distinct from each other and from the metals, both in their essence and the laws they obey? If there be really sixty distinct substances, there may be also sixty distinct laws of nature, one for each substance, and the possibility of grasping chemistry by the human mind, of rendering it a thing reasonable and capable of being understood, is hopeless, and it will remain a sort of natural history, and never take rank as an exact science.

That new qualities should grow out of such strange combinations, and that the eye, ear, and hand should no longer be able to tell that there remains in the new substance any of the old elements, is not at all wonderful to him who has tried to conceive how infinitely small the atoms themselves which compose matter must be. He who tries to draw a hundred lines in the space of an inch finds it hard to do, and hard to distinguish when done. When a thousand lines have been drawn in an inch, only a powerful microscope reveals their existence, but when each of these is again divided into a thousand, and the result is expressed by the word millionth of an inch, the division has already passed too far to be distinguished by the senses or conceived by the mind. Now, as far as the substance of things is concerned, we have reason to believe that the atoms of matter are far minuter than would be expressed by millions and billions and trillions, as divisions of an inch, and the words convey as little meaning to our minds as the proceeding to our senses. Nevertheless, there the atoms are, and there they can be recognised by the inevitable test of weight; and, long after they have vanished from our senses, Dalton has proved that, when the atoms of one substance take kindly to the atoms of another, they receive each other into their new home, they distribute the new guests symmetrically each into their respective chambers; that when the distribution is completed, nothing is permitted to disturb the symmetry of the arrangements, and the superfluous guests are summarily ejected. Even in these hidden recesses Dalton found nature true to symmetry, proportion, and weight; rigid in system, unbending in law: and thus the atomic theory became for chemistry in the hidden recesses of nature what gravity had become for astronomy in the gigantic scale of the celestial universe.

By creating the science of atomic chemistry, Dalton achieved two things. He gave to chemistry rank as an exact science,

Happily for chemistry and for science, a large field of discovery has been growing in extent, has been rescued from the region of empiricism and added to that of exact science by the investigations of the last thirty years. A large domain of chemistry may be said to have been conquered from chemistry and annexed to natural philosophy by recent discovery, or, to put it another way, the chemists have become to a large extent students of physical laws, and have contributed jointly with the physicists to create the region of exact science known by the name of physical chemistry or chemical physics. It comprehends a wide space of ground common to both sciences; and a large portion of this new domain is due to the genius of Faraday, and has entitled him justly to this memorial inscription written by Tyndall, to which the philosophers of Europe will subscribe their names FARADAY A DISCOVERER.

The region of Faraday's discoveries, which entitle him to the gratitude of the human race, is mainly that mid-region between exact physical science and empirical chemistry. His great theorem is this: The things which seem so different are the same under different aspects; and the forces of matter which seem so opposite are but the

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Littell's Living Age, Volumen98