MANURE. Every substance which has been used to improve the natural soil, or to restore to it the fertility which is diminished by the crops annually carried away, has been included in the name of manure. There are some substances which evidently belong to both classes of manure. Of these lime, either in its caustic state of quick lime, or its milder form of a carbonate or chalk, is the principal. Lime, being an earth less porous than sand, and more so than clay, has an improving effect on soils in which either sand or clay prevails ; but it has also a chemical effect as an alkaline earth.
Perhaps the most important class of manures are the excrements of animals. From the most ancient times of which there are any re cords, the dunging of a field has been an im portant part of cultivation. The preparing of the dung of animals, so as to render it more efficacious, is a later improvement, which however has not yet attained the perfection of which it is capable. A mixture of the dung of all the different animals kept on a farm, with all the straw that can be afforded, will give a manure of an average strength, which may be used upon all kinds of land. The
great use of liquid manure on light soils is to impregnate them with soluble matter, which, being diffused through their substance, sup. plies nourishment to the roots of plants, wherever they may shoot out. It may be ap plied to the land at any time before the seed is sown, and soon after, when the blade springs up or the seed begins to form. The great effect of liquid manure has set farmers on finding some artificial substitute for it. Such substitutes are obtained by mixing all kinds of refuse animal matter (such as the refuse from oil mills and other manufactories) with water, and inducing putrefaction. This be 3omes a branch of trade in those countries where nothing will grow without manure. the increase of manure by the formation of :omposts is well known in many parts of Britain, and by their means the land has in natty districts been rendered much more pro luctive.