known by the science of man. If they be many, there is need of mutual accommodation and reciprocal action, to suit them one to the other, and make them accomplish a good end. If they be few, there is equal need of a nice adjustment, to make them fulfil the infinitely varied purposes which they serve. If the number of elementary bodies in nature be sixty, as chemical science says, provisionally, that they are; and if the number of properties possessed by them-mechanical, chemical, electric, magnetic, vital - be also numerous, there is surely need of a marshalling of these hosts, to keep them from clashing, and working confusion and destruction. Or, if scientific research can succeed in showing that all these may be reduced to a dozen, or half a dozen, an amazing skill must be required to make them produce those infinitely diversified bodies and those wonderfully constructed frames which we see in nature. I have heard Paganini draw exquisite music from one string, wrought upon in all sorts of directions and with all kinds of flexures; and I have listened to strains produced by hundreds of instruments, each with a complexity of strings: but in the one case, as in the other, combination and skill of the highest order were required to create and sustain the melody and the harmony.

Carrying with us these two principles, so obvious, and yet so frequently overlooked, let us now take a glance at some of the recent speculations as to the construction of the universe. We find in the physical world at least two ultimate existences, - Matter

CONSERVATION OF force.

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and Force. I believe that we know both of these by intuition, and by no process can we get rid of the one or the other. As to Force, it will be expedient to look for a moment at the grandest scientific truth established in our day, a doctrine worthy of being placed alongside that of universal gravitation, I mean that of the Conservation of Physical Force; according to which, the sum of Force, actual and potential, in the knowable universe is always one and the same: it cannot be increased, and it cannot be diminished. It has long been known that no human, no terrestrial power can add to or destroy the sum of Matter in the cosmos. You commit a piece of paper to the flames, and it disappears; but it is not lost: one part goes up in smoke, and another goes down in ashes; and it is conceivable that at some future time the two may unite, and once more form paper. Why may not imagination trace the noble dust of Alexander, till we find it stopping a bung-hole?" "As thus: Alexander died, Alexander was buried, Alexander returneth to dust; the dust is earth; of earth we make loam: and why of that loam, whereto he was converted, might they not stop a beer-barrel?

"Imperial Cæsar, dead, and turned to clay,
Might stop a hole to keep the wind away:

O, that the earth, which kept the world in awe,
Should patch a wall t' expel the winter's flaw!"

As man cannot create or annihilate matter, so he cannot create or annihilate force. This doctrine

has been scientifically established in our day by men like Mayer, Joule, Henry, and others. We now regard it as one and the same force, but under a vast variety of modifications, which warms our houses and our bodily frames, which raises the steam and impels the engine, which effects the different chemical combinations, which flashes in the lightning and lives in the plant.* Man may direct the force, and make it go this way or that way; but he can do so only by means of force under a different form, by force brought into his frame by his food, obtained directly, or indirectly through the animal, from the plant, which has drawn it from the sun; and as he uses or abuses it, he cannot lessen or augment it. I move my hand; and, in doing so, I move the air, which raises insensibly the temperature of the room, and may lead to chemical changes, and excite electric and magnetic currents, and take the circuit of the universe without being lost or lessened. Now the bearing of this doctrine on religion seems to be twofold. First, it furnishes a more striking manifestation than any thing known before of the One God, with his infinitely varied perfections, of his power, his knowledge, his wisdom, his love, his mercy; and we should see that one Power blowing in the breeze, smiling in the sunshine, sparkling in the stars, quickening us

* I was prepared, from its first announcement, to receive this truth; for it follows directly from a doctrine laid down by me twenty-one years ago, in my work on "The Method of the Divine Government" (Book II.), that all bodies possess fixed properties, which cannot be increased nor lessened.

CORRELATION OF THE FORCES.

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as we bound along in the felt enjoyment of health, efflorescing in every form and hue of beauty, and showering down daily gifts upon us. The profoundest minds in our day, and in every day, have been fond of regarding this force, not as something independent of God, but as the very power of God acting in all action; so that "in him we live, and move, and have our being." But, secondly, it shows us that in God's works, as in God himself, there is a diversity with the unity; so that force manifests itself now in gravity, now in molecular attraction and motion, now in chemical affinities among bodies, now in magnetic and diamagnetic properties, now in vital assimilation. And we see

that all these forces are correlated: so that the doctrine of the Correlation of all the varied Physical Forces stands alongside of the Conservation of the one Physical Force; and by the action of the whole, and of every part made to combine and harmonize, there arise beauteous forms and harmonious colors; the geometry of crystals; the types of the plant and of every organ of the plant, the branches, the roots, the leaves, the petals, the pistils, the stamens; and the types of the animal, so that every creature is fashioned after its kind, and every limb takes its predetermined form, while there is an adaptation every one part to every other, of joint to column, and joint to joint, of limb to limb, and of limb to body, of the ear to the vibrating medium, and the nostrils to odors, and the eye to the varied undulations of light.

of

I

So much for Force, with its Correlations. But with the Forces we have the Matter of the universe, in which, I believe, the Forces reside. It is maintained that the worlds have been formed out of Star Dust. Now, I have to remark as to this star dust, first of all, that it is at best an hypothesis. No human eye, unassisted, has ever seen it, as it gazed, on the clearest night, into the depths of space. It is doubtful whether the telescope has ever alighted upon it, in its widest sweeps. Lord Rosse's telescope, in its first look into the heavens, resolved what had before been reckoned as star dust into distinctly formed stars. But I am inclined to admit the existence of star dust as an hypothesis. believe it explains phenomena which require to be explained, and which cannot otherwise be accounted for. I allow it freely, that there is evidence that the planets and moons and sun must have been fashioned out of some such substance, at first incandescent, and then gradually cooling. But, then, it behoves us to look a little more narrowly into the nature of this star dust. Was it ever a mass of unformed matter, without individuality, without properties? Did it contain within itself these sixty elementary substances, with their capacities, their affinities, their attractions, their repulsions? When a meteor comes, as a stranger, within our terrestrial sphere, either out of this original star dust or out of planets which have been reduced to the state of original star dust, it is found to have the same components as bodies on our earth, and these with