"I have made an experiment with a soil of ordinary tenacity, to ascertain how much water it would hold in suspension, with the following result: One cubic foot of earth held 0.4826434 cubic feet of water; three feet of dry soil of that character will receive 1.44793 ft. vertical depth of water before any drains off, or seventeen and three-quarter inches, equal to nearly six month's rain-fall. One cubic foot of earth held 3.53713 gallons of water, or if drains are three feet deep, one square foot of surface would receive 10.61 gallons of water, before saturation. Other soils would sustain a greater or less quantity, according to their character." Besides this power of retaining water, when brought into contact with it, the soil has, in common with other porous bodies, the power of drawing up moisture, or of absorbing it, independent of gravitation, or of the weight of the water which aids to carry it down into the soil. This power is called _capillary attraction_, from the hair-like tubes used in early experiments. If very minute tubes, open at both ends, are placed upright, partly immersed in a vessel of water, the water rises in the tubes perceptibly higher than its general surface in the vessel. A sponge, from which water has been pressed out, held over a basin of water, so that its lower part touches the surface, draws up the water till it is saturated. A common flower-pot, with a perforated bottom, and filled with dry earth, placed in a saucer of water, best illustrates this point. The water rises at once to a common level in the pot and outside. This represents the water-table in the soil of our fields. But, from this level, water will continue to rise in the earth in the pot, till it is moistened to the surface, and this, too, is by capillary attraction. The tendency of water to ascend, however, is not the same in all soils. In coarse gravelly soils, the principle may not operate perfectly, because the interstices are too large, the weight of the water overcoming the power of attraction, as in the cask of stones or shot. In very fine clay, on the other hand, although it be absorptive and retentive of water, yet the particles are so fine, and the spaces between them so small, that this attraction, though sure, would be slow in operation. A loamy, light, well pulverized soil, again, would perhaps furnish the best medium for the diffusion of water in this way.