The amount of living matter in the universe, so far as we can penetrate it, compared with the non-living, is, in amount, like a flurry of snow that whitens the fields and hills of a spring morning compared to the miles of rock and soil beneath it; and with reference to geologic time it is about as fleeting. In the vast welter of suns and systems in the heavens above us, we see only dead matter, and most of it is in a condition of glowing metallic vapor. There are doubtless living organisms upon some of the invisible planetary bodies, but they are probably as fugitive and temporary as upon our own world. Much of the surface of the earth is clothed in a light vestment of life, which, back in geologic time, seems to have more completely enveloped it than at present, as both the arctic and the antarctic regions bear evidence in their coal-beds and other fossil remains of luxuriant vegetable growths. Strip the earth of its thin pellicle of soil, thinner with reference to the mass than is the peel to the apple, and you have stripped it of its life. Or, rob it of its watery vapor and the carbon dioxide in the air, both stages in its evolution, and you have a dead world. The huge globe swings through space only as a mass of insensate rock. So limited and evanescent is the world of living matter, so vast and enduring is the world of the non-living. Looked at in this way, in the light of physical science, life, I repeat, seems like a mere passing phase of the cosmic evolution, a flitting and temporary stage of matter which it passes through in the procession of changes on the surface of a cooling planet. Between the fiery mist of the nebula, and the frigid and consolidated globe, there is a brief span, ranging over about one hundred and twenty degrees of temperature, where life appears and organic evolution takes place. Compared with the whole scale of temperature, from absolute zero to the white heat of the hottest stars, it is about a hand's-breadth compared to a mile. Life processes cease, but chemical and mechanical processes go on forever. Life is as fugitive and uncertain as the bow in the clouds, and, like the bow in the clouds, is confined to a limited range of conditions. Like the bow, also, it is a perpetual creation, a constant becoming, and its source is not in the matter through which it is manifested, though inseparable from it. The material substance of life, like the rain-drops, is in perpetual flux and change; it hangs always on the verge of dissolution and vanishes when the material conditions fail, to be renewed again when they return. We know, do we not? that life is as literally dependent upon the sun as is the rainbow, and equally dependent upon the material elements; but whether the physical conditions sum up the whole truth about it, as they do with the bow, is the insoluble question. Science says "Yes," but our philosophy and our religion say "No." The poets and the prophets say "No," and our hopes and aspirations say "No."