Soils are the chief form of national wealth. Minerals, such as coal and iron, are of course extremely valuable, and help to make an industrious race rich; but the land is the main thing, after all, and by land we mean soil. The two words are almost synonymous. But since the soil is formed chiefly of débris brought from the mountains, it would be more true to say that these are the real sources of wealth. Soils contain besides a large amount of valuable organic matter (that is, decayed matter which has once had animal or vegetable life) different kinds of minerals, which are necessary to the support of plant life: potash, soda, carbonate of lime, silica, magnesia, iron, phosphorus, and manganese in their various compounds are all present in the rocks of which mountains are composed. We must again fall back upon "Modern Painters" for an effective description of the forming of soil by destruction of the hills:-- "The higher mountains suffer their summits to be broken into fragments and to be cast down in sheets of massy rock, full, as we shall presently see, of every substance necessary for the nourishment of plants; these fallen fragments are again broken by frost, and ground by torrents into various conditions of sand and clay,--materials which are distributed perpetually by the streams farther and farther from the mountain's base. Every shower that swells the rivulets enables their waters to carry certain portions of earth into new positions, and exposes new banks of ground to be moved in their turn.... The process is continued more gently, but not less effectively, over all the surface of the lower undulating country; and each filtering thread of summer rain which trickles through the short turf of the uplands is bearing its own appointed burden of earth down on some new natural garden in the dingles beneath." It may be laid down as a simple economic truth, that no nation can be powerful, rich, or prosperous, unless it possess in the first place a good soil. Other conditions, such as large navigable rivers, a good seaboard for harbouring ships, are also important; but unless the land will yield plenty of food, the population cannot be very great, for people must be fed. Foreign supplies of corn at a low price, meat and provisions of various kinds, supplement what is grown in England; but without a good soil we could not have become a powerful nation. A high state of civilisation is in a large measure to be traced to climate and soil. The sequence is somewhat as follows:-- Mountains collect rain. Rain fills the rivers. Rivers make rich alluvial plains. Agriculture follows; and food is produced. Abundant food maintains a large population.