It is for the sake of a somewhat commensurate appreciation of vitality, of high-wrought molecular organization, that it is necessary, again and again, to point out the might of potentiality intrinsic to matter, the vast and specific stores of force locked up in the peculiar molecular entanglements which constitute our different substances. All forms of matter are essentially magazines of equilibrated energies: inert against such other energies as have no power to disturb their equilibrium, but seething with incalculable commotion against such other energies as have power to disturb their equilibrium.

What H2O is to the steam-engine, the moving substance, the protoplasm, is to the living engine. Machinery is fastened on to both these motor powers exactly in the same manner. The expansion and contraction of H2O give motion to the prearranged and molecularly unyielding levers of the steam-engine. The expansion and contraction of the protoplasm give motion to the prearranged and molecularly unyielding levers of the animal engine. We see the correspondence between an engine and a higher organism is even more complete than is generally conceived by philosophers of the purely mechanical school.

Only, the specific power of the slightly complicated molecule H2O cannot possibly afford any standard for the estimation of the specific power of the immensely more complicated molecule constituting protoplasm. Protoplasm differs from water in proportion to its synthetical wealth. Whatever synthetical wealth may be the symbol of, in its gradations is to be sought the source of all difference in Nature. This is the gist of what chemistry teaches: the work of Nature consists in molecular synthesis. It has required the ceaseless toil of endless ages to build up the molecule of living matter. Let us then value it accordingly, and nevermore view it under the degrading aspect of stolid machinery.

Motility, then, consists in the alternate expansion and contraction of protoplasm, which expansion and contraction are incited by a process of chemical composition and decomposition occurring within the protoplasm. The property of occupying so much more or so much less space, under these different conditions, belongs entirely to the respective organic substances, which alternately fill the larger and the smaller space. The forces which are brought into activity during the process are forces of a known kind, but essentially inherent in the living substance. They are stimulated, not transferred. They are a display of intrinsic power, not an application of extrinsic power. They are not the heat of combustion pushing together or dragging asunder the molecules of the organic substance; they are part of the expression, i. e., of the influence on the medium, of those most specific chemical affinities which synthetical elaboration has ingrained into the constitution of the protoplasm.

If, in contemplating this truth, so positively disclosed by the study of living matter, it should become evident that the display of all other

force is exactly of the same stimulated and not transferred nature, then, surely, a great advantage will have been thus gained toward a correct understanding of natural phenomena and their relation to each other.

It would then be clearly perceived that Nature does not consist of so many particles of inert matter, held together or pushed about by a set of mysterious agents; but that it rather consists in the disturbance, the overthrow, and the new formation, of equilibrated states of energies.

66

I have found myself reluctantly compelled to advance this general statement, in order to fulfill the obligations undertaken in this section. For, how am I to establish the gradual, unbroken development of the organic world from inorganic beginnings, when already in the domain of inorganic activity there are believed to exist so many different modes of force, so many kinds of self-sustained and transferable agents? It is true, the so-called forces, the specific motive activities, by diving into certain substances, are said to be in some unknown way "transformed " or converted into each other: so much friction into so much heat, or so much electricity. In this conception the identity of a supposed agent or force is evidently sustained in thought. Struck by the definite proportionality found to obtain between the changes occurring simultaneously in the substratum from which the force is thought to have been transferred, and the substratum to which it is thought to have been transferred, the mind is induced by means of a fictitious entity substantially to connect the changes as such, losing sight of the true substances, of which the changes are in reality mere affections. However much the notion may be formally repudiated, the forces are nevertheless in science still conceived as specific entities; to which the current expressions "correlation of forces, "equivalence of forces," "transmutation of forces," etc., bear sufficient witness.

If friction can become electric force, why cannot heat become vital force? And this is exactly what is generally maintained. If it be the rubbing that is or makes the electricity in the sealing-wax, then, surely, it must be the heat that is or makes the vitality in the hen'segg. This also, but somewhat more reservedly, is at times advanced. So much mechanical force converted into so much electric force, in the former instance, whereby-as easily perceived-the preëstablished specific molecular constitution of the sealing-wax is counted for nothing so much heat converted into so much vital force, in the latter instance, whereby the preëstablished most specific molecular affinities within the egg-substance are counted for nothing. Is not even the proportionality between the changes entirely limited and quantitatively determined by the nature and state of the manifesting substances?

Whether the forces be conceived as specific entities, as definite modes of motion, or as different affections of matter, the idea of their equivalence and convertibility is just as unwarranted, though not so palpably incongruous, as the idea of the equivalence and convertibility of air

vibrations and sound-perception, of ether-vibrations and light-perception. A certain, even quantitatively definite relation obtains between the intensity of stimulation and the stimulated effect, but that relation is neither one of equivalence nor of convertibility. This fact is universal in Nature, but becomes the more obvious the less the mutually affecting substances resemble each other. It is just as impossible that one kind of force can be converted into another kind of force, as it is impossible for any kind of force to originate out of nothing, or to exist without substratum.

A "force-directing" machine or apparatus corresponds to a wellknown intelligible fact. A "force-transforming" machine or apparatus corresponds to something altogether unintelligible. If substances had really any such transforming effect on forces, even then they would. themselves constitute specifically intervening powers. But this also is hyperbolical, for it does not adequately express the part which substances actually play in the manifestation of forces.

The now so famous notion of the equivalence and convertibility of forces indicates certainly a desirable attempt to bring under the grasp of Science the subtile balance of energies constituting our phenomenal world, but it partakes still too much of the old metaphysical weakness, under which we are wont to seize the shadow and lose the substance. By admitting molecular affections into the vicious circle of mechanical equivalence, it has, however, imported into it an insuppressibly qualitative element, that sooner or later, by its intense expansiveness, will break the narrowing spell, and open to scientific knowledge new fields. of unexpected wealth.

The whole mechanical view of Nature rests chiefly on the supposition that effects are equal to their causes, that they are indeed the causes themselves, metamorphosed in appearance. This notion is radically erroneous, and can never lead to an understanding of reality. Causa non æquat effectum. In Nature there exists nothing corresponding to the so-called efficient causes of science, whether single or plural. The scientific conception of cause is a dynamical fiction, made to suit a realm of phantasmal inertia, in which molecularly imperturbable masses pursue forever an unopposed course in a resistless medium. How can we gain an insight into reality by always mathematizing it away?

In Nature all manifestations are the work of opposition and perturbation; agitation of preexisting states, and subversion of the same. It is in this intrinsic potentiality and mutual affectibility of so-called masses that Nature has its being, its subsistence, and its perfectibility. The substrata of reality are not merely ponderable or imponderable vehicles of locomotion; but concentrations of actual and potential energies, thrilling through and through with consonant sensitiveness, reverberating with an accent of their own every commotion from the centre of the skies to the centre of the earth.

The entire result of development is preserved in the synthetical intricacies of matter and ether, the sensible and the supersensible substratum. All developmental achievement is embodied in what we chemically call complexity of composition. The more complex a substance, the greater its intrinsic value, the more specific its inherent power, and the less congruous in consequence its response to outside influences.

We cannot make any considerable progress in the philosophy of reality, of which the understanding of our own life is the consummation, before we have first formally reënthroned into their actual seat of power the sovereign energies, so strangely slighted during the long reign of visionary potentates-the eras of anthropomorphism and metaphysics.

Now that we are avowedly appealing to Nature for knowledge, it behooves us to become natural in our mode of thinking. To fix our attention merely on changes and their relation to each other is to grasp at the shadow of reality. That which changes is in every respect the substance, the potentiality and actuality in the case; and it is essentially its specific molecular constitution which determines the nature of the change qualitatively and quantitatively. The scientifically ascertained, most specific behavior shown by the various substances, with regard to their manifestation of different modes of force, or even of one and the same mode of force, is in itself abundant proof that that which we call forces are merely specific modes of reaction on the part of the various substances.

This somewhat lengthy but indispensable discussion on the nature and seat of force will save us the far greater labor of attempting to account for life by computing the foot-pounds of mechanical energy of which it is supposed to be the transformation; or of seeking a standard for the valuation of brain-power, or any other vital activity, by accurately determining the units of heat obtainable from the substances which exhibit these activities.

"But," it will be asked, "if combustion is in no way essential to the manifestation and production of motility, what part is actually played by the oxygen, which is known to permeate all protoplasm, and which is inhaled in such vast quantities by higher organisms?"

Oxygen is the mighty scavenger in the vital economy, the general purifier and clearer. Everywhere among the crevices and interstices of the vital nexus it lies in wait, seizing upon all stray stuff-waste products of function and unassimilable matter of all kinds-and converting the same forthwith into harmless and eliminable compounds. Besides, the heat evolved during this entirely depurative process helps essentially to compose the calorific medium of the organism. But oxidation is in no manner directly conducive to vitality. Within the organism combustion merely hides away death; does not kindle the flame of life; belongs to the domain of destruction, not to that of construction,

Having thus to some extent prepared the way for a more strictly chemical and physical appreciation of vital phenomena, we will proceed, in the next paper, to inquire by what agencies the chemical composition and decomposition of the living substance are effected.

[To be continued.]

THE ASTRONOMICAL HISTORY OF WORLDS.

THE

BY PROFESSOR DANIEL VAUGHAN.

HE information which geologists derive from the evidences of organic remains does not wholly satisfy the keen appetite of educated minds for a knowledge of the mysteries of Nature and the revolutions of past times. The relics disentombed from our globe give no clew to its origin; and they throw but little light on the great physical events which transpired before life appeared on its surface. There are, however, reasonable hopes that the records which are wanting on this earth may be supplied from the heavens; and that some general cause, to which the numerous orbs of celestial space are indebted for their existence, may be revealed from the peculiar character of their movements, or from some of the mysterious phenomena which they occasionally exhibit. In associating his researches with those of the geologist, and in taking cognizance of the great events in the course of time, the astronomer may enhance the value of the inquiries which more commonly fall to his lot. A knowledge of the condition of the earth in past ages is calculated to give much insight into the state of similar orbs in remote space; and opinions of the habitability of other planets must be more valuable in proportion as geology and terrestrial physics show more definitely how our globe acquired and how long it can retain the conditions necessary for the maintenance of life.

The tendency to widen the range of its inquiries and to speculate on the origin of the celestial bodies cannot be considered as a new feature of astronomy. The sudden appearance of the new stars, in 1572 and 1604, led Tycho Brahe and Kepler to the belief that the cosmical vapor or exceedingly rarefied matter of space was occasionally condensed to form great stellar orbs. These crude notions of the quick growth and ephemeral life of great suns were gradually replaced by views less repugnant to reason and experience. In the succeeding age the faintly luminous spots which the telescope revealed in the heavens were regarded as primitive chaotic matter exceedingly rarefied by intense heat, and they were supposed to be undergoing a slow cooling and a gradual condensation which would ultimately convert them into suns or into planetary systems. This opinion, however, though