THE organized being that we observe on the surface of the globe does not subsist solely by the nourishment absorbed, sometimes in the form of aliment, sometimes in that of atmospheric air; it needs besides, heat, electricity, and light, which are like a secret and life-giving spring for the world. Its organs are subject to the twofold influence of an inner medium, represented by the humors moistening its tissues, and of an outer medium, composed of all those subtle and fluid agents with which space is filled. This close interdependence of beings and of the media in which they are immersed, too plain to have quite escaped notice, yet too complex for analysis by science in its infancy, has been brought in our day under piercing and methodical investigation, yielding results of remarkable interest. Light especially takes a part in this combination deserving deep study. Whether organic existence in its simplest expression and its lowest degree be considered, or whether we regard it in its highest functions, the influence of light upon it strikes us in the most strange and unlooked-for relations. Lovely forms and vivid colors, the hidden harmonies of life as well as its dazzling brightness and bloom, alike claim mysterious connection with that golden mist diffused by the sun over the world.
From this point of view, modern science finds reason in the simple worship paid by primitive man. It helps us to understand the divine honors given to the star of day among the earliest civilized nations, and the pathetic terror those child-like races suffered when, at evening, they saw the crimson globe, that was the source for them of all power and all splendor, slowly disappear in the horizon. That pious idolatry, far from being a mere utterance of gratitude for the wealth of fertility scattered by the sun over earth, was a homage, too, to the comforting source of brightness and joy, revealing the natural affinity between man and light. The Vedas, the Orphic hymns, and other remains of the earliest religions, are full of this feeling, which appears again in many poets and philosophers of antiquity, Lucretius and Pliny among others. Dante, invoking so often "the divine and piercing. light," crowns his poem by a hymn which more than any thing else is a symbolic description of the supreme brightness. On the other hand, laborers, gardeners, physicians, unite in bearing witness to the beneficial effects of light. Naturalists and philosophers, too, in all ages, impressed with the power of the sun, have described its manifold effects. Alexander Humboldt, following Goethe and Lavoisier, often notices its its various influences. Yet it was not until the middle of the eighteenth