But why is it that light soils, need more manure than loamy or heavy lands? We answer--because, in the first place the rains which quickly descend through the open soil, wash down out of the reach of vegetation the soluble fertilizing matters, especially the nitrates, for which the soil has no retentive power; and in the second place, from the porosity of the soil, the air has too great access, so that the vegetable and animal matters of manures decay too rapidly, their volatile portions, ammonia and carbonic acid, escape into the atmosphere, and are in measure lost to the crops. From these combined causes we find that a heavy dressing of well-rotted stable manure, almost if not entirely, disappears from such soils in one season, so that another year the field requires a renewed application; while on loamy soils the same amount of manure would have lasted several years, and produced each year a better effect. We want then to _amend_ light soils by incorporating with them something that prevents the rains from leaching through them too rapidly, and also that renders them less open to the air, or absorbs and retains for the use of crops the volatile products of the decay of manures. For these purposes, vegetable matter of some sort is the best and almost the only amendment that can be economically employed. In many cases a good peat or muck is the best form of this material, that lies at the farmer's command. I.--_Its absorbent power for liquid water_ is well known to every farmer who has thrown it up in a pile to season for use. It holds the water like a sponge, and, according to its greater or less porosity, will retain from 50 to 100 or more _per cent._ of its weight of liquid, without dripping. Nor can this water escape from it rapidly. It dries almost as slowly as clay, and a heap of it that has been exposed to sun and wind for a whole summer, though it has of course lost much water, is still distinctly wet to the eye and the feel a little below the surface.