tage. We shall hereafter see electricity in a thousand conditions in which we did not before suspect it. Every blaze, every luminous atom becomes an electrical phenomenon. Even if a body does not cast light, it is a center of electrical action if it radiates heat. The domain of electricity is therefore extended over all nature, and even possesses us; for is not the eye, in fact, an electrical organ? Such are the results which we obtain in these questions of detail; those that concern the philosophy of science are no less important.
One of our most difficult problems is that of actions at a distance. Are they real? Of all those which seemed indisputable to us, gravitation is the only one that is left. Will it also escape? The laws of its action themselves provoke the thought. The nature of electricity is another of these great Unknowns. It reverts to the question of the condition of electrical and magnetic forces in space. Behind this rises the most important problem of all—that of the nature and properties of the substance that fills space, of the ether, its structure, its movements, and its limits—if it has any. We see this question becoming more and more dominant over all the others. The knowledge of the ether seems destined not only to reveal to us the condition of the imponderable substance, but also the nature of matter itself and its inherent properties—weight and inertia.
The ancient systems of physics summarized everything as formed of water and fire. Modern physics will shortly be asking if all existing things are not modalities of the ether. Here lies the ultimate end of our knowledge, the culmination of all that we can hope to learn. Shall we ever reach it? Soon? We do not know. But we have reached a greater height than ever before, and we have gained a solid point of support which will make our upward progress and search for new truths easier. The way that is opening before us is not too steep, and the next step does not look inaccessible. There is a numerous company of seekers full of ardor and knowledge; and we wait with confident hope all the attempts that will be made in that direction.—Translated for The Popular Science Monthly from the Revue Scientifique.