But the nineteenth century has not only opened our eyes to the æsthetic enjoyment of the microscopic world; it has shown us the beauty of the greater objects in nature. Even at its commencement it was the fashion to regard the mountains as magnificent but forbidding, and the sea as sublime but dreaded. At its close the majority of educated people--especially they who dwell in the great cities--are delighted to enjoy the glories of the Alps and the crystal splendor of the glacier world for a fortnight every year, or to drink in the majesty of the ocean and the lovely scenery of its coasts. All these sources of the keenest enjoyment of nature have only recently been revealed to us in all their splendor, and the remarkable progress we have made in facility and rapidity of conveyance has given even the less wealthy an opportunity of approaching them. All this progress in the æsthetic enjoyment of nature--and, proportionately, in the scientific understanding of nature--implies an equal advance in higher mental development and, consequently, in the direction of our monistic religion. The opposite character of our _naturalistic_ century to that of the _anthropistic_ centuries that preceded is especially noticeable in the different appreciation and spread of illustrations of the most diverse natural objects. In our own days a lively interest in artistic work of that kind has been developed, which did not exist in earlier ages; it has been supported by the remarkable progress of commerce and technical art which have facilitated a wide popularization of such illustrations. Countless illustrated periodicals convey along with their general information a sense of the inexhaustible beauty of nature in all its departments. In particular, landscape-painting has acquired an importance that surpassed all imagination. In the first half of the century one of our greatest and most erudite scientists, Alexander Humboldt, had pointed out that the development of modern landscape-painting is not only of great importance as an incentive to the study of nature and as a means of geographical description, but that it is to be commended in other respects as a noble educative medium. Since that time the taste for it has considerably increased. It should be the aim at every school to teach the children to enjoy scenery at an early age, and to give them the valuable art of imprinting on the memory by a drawing or water-color sketch.