... unlike the plant, they usually possess much more of the latter than of the former. In the plant, the organic matter constitutes the most considerable portion of the whole. In the soil, on the ... fertile soil, and therefore we will examine the nature of different soils, in order that we may understand the relations between them and plants. What is a fixed character of soils? How is the ... soil, which comprise the acids, alkalies, and neutrals, furnish plants with their ashes, and are the most necessary to the fertility of the soil. GEOLOGY. a sandy soil, a clay soil, etc. These...