Translations:Benutzer:Arian/Klett-Mini-Test/427/en

The element of air rests now still over the village bounds, now sweeps gently, now stormily across the land. Just as the precipitation does, so do the air currents in wind and weather, reaching across lands and seas, yet at every earthly place where obstacles bar the way — be it a ridge of hills, be it trees, hedges and the like — become eddied, moderated, or brought to rest altogether. Above all the near-ground air layer persists longer under the plant cover and stands in constant exchange with the soil air that dwells for shorter or longer periods in the cracks and pores of the living topsoil. The purely physical, inorganically lifeless character of the air element shows itself in its substance composition. The chief constituents, oxygen and nitrogen — in living things highly active substances — enter in the outside air only into compounds with themselves and are therefore in the highest degree sluggish in their reactions. The air element behaves otherwise in the soil. There it enters into relationship with the elements of earth and water, enlivens itself to its full reactive force, entering into new compounds. Another mode of appearance of air in motion is the pressure it exerts when, in wind and storm, it drives water into waves, makes the grain undulate, sets the leaves of the poplar trembling, and brings whole forests down.