The truths here enunciated cannot be too carefully pondered. In its modern progress Science has been constantly warned off from the field of Philosophy, as having no concern whatever with its issues or interests. But Science has no more choice or responsibility in regard to the results of its work than it has with regard to the phenomena which it investigates. If it is to be suffered to exist at all, it must proceed with its labor of investigating facts and establishing principles; to what conclusions these will lead depends upon nobody's preference, but upon the constitution of the universe itself. If the scheme of being around us is a harmonized and unified order, where all the parts are in reciprocal sympathy, then he who strikes an impulse is not to be called to account for the sweep and compass of the undulations which follow. Science may be occupied in her legitimate duty with simple laboratory experiments, and establish results that will thrill through all spheres of thought, and reach to the very core of philosophy.
Such a step was taken in the last century in establishing the indestructibility of matter. The problem that had baffled philosophy, for thousands of years, was settled by the experimenters. The truth which was inaccessible to speculation was arrived at by the physicists and chemists. It had been believed, for centuries, that in the changes of form—the appearances and disappearances of Nature—existence itself was implicated, and matter, the substratum of being, was continually created and destroyed. The poetic divination—
Bideth never in one shape,
But forever doth escape
Into new forms"—
only became a demonstrated truth when the mechanics had perfected the chemical balance and made it possible to pursue the course of material transformations. It was then found that the old belief in the destructibility of matter was without foundation, and that the persistence of material elements through all changes of form was demonstrated by every particle of evidence that bore upon the case. Philosophy, which aims at the deepest explanation of the order of things around us, if it has any aim worth pursuing, thus derived a new datum from the workshop; but how foolish to assume that, in elaborating it, the chemists were inspired with any purpose to trench upon the domain of Philosophy!
But this research, which ended in the establishment of the law that matter is indestructible, was but an apprenticeship for deeper and more delicate investigations of the same kind. The use of the balance led to the discovery of quantitative chemistry, the highest phase of the science, and strengthened the mental habit of regarding phenomena in their quantitative relations. Matter is not only associated with forces, but it is manifested and known through its essential and inseparable activities. It is not only determined by its forces, but it is measured by them. The very instrument by which matter was proved to be indestructible, was but a device for showing the constant relation of material bodies to the force of gravity. Cohesion, affinity, heat, light, and magnetism, are but dynamic affections of matter, which are involved in all its changes, and it was simply inevitable that when one element of things was proved to be essentially indestructible, through every mutation of form, the same inquiry should be pressed in regard to this character of the other forces. Naturally, and quite necessarily, the disciplined scientific thinkers of different countries, with no knowledge of each other's purposes, and proceeding from different points of view, were led to engage with the experimental problem of the quantitative interactions of