By _muck_, we mean the vegetable deposits of swamps and rivers. It consists of decayed organic substances, mixed with more or less earth. Its principal constituent is _carbon_, in different degrees of development, which has remained after the decomposition of vegetable matter. Muck varies largely in its quality, according to the amount of carbon which it contains, and the perfection of its decomposition. The best muck is usually found in comparatively dry locations, where the water which once caused the deposit has been removed. Muck which has been long in this condition, is usually better decomposed than that which is saturated with water. The muck from swamps, however, may soon be brought to the best condition. It should be thrown out, if possible, at least one year before it is required for use (a less time may suffice, except in very cold climates) and left, in small heaps or ridges, to the action of the weather, which will assist in pulverizing it, while, from having its water removed, its decomposition goes on more rapidly. After the muck has remained in this condition a sufficient length of time, it may be removed to the barn-yard and composted with the lime and salt mixture (described on page 115) in the proportion of one cord of muck to four bushels of the mixture. This compost ought to be made under cover, lest the rain leach out the constituents of the mixture, and thus occasion loss; at the end of a month or more, the muck in the compost will have been reduced to a fine pulverulent mass, nearly equal to charcoal dust for application to animal excrement. When in this condition it is called _prepared_ muck, by which name it will be designated in the following pages. Muck should not be used immediately after being taken from the swamp, as it is then almost always _sour_, and is liable to produce sorrel. Its _sourness_ is due to _acids_ which it contains, and these must be rectified by the application of an alkali, or by long exposure to the weather, before the muck is suitable for use. LIME AND SALT MIXTURE. [What proportions of lime and salt are required for the decomposing mixture? Explain the process of making it. Why should it be made under cover?] The lime and salt mixture, used in the decomposition of muck, is made in the following manner: RECIPE.--Take _three_ bushels of shell lime, _hot from the kiln_, or as fresh as possible, and slake it with water in which _one_ bushel of salt has been dissolved. Care must be taken to use only so much water as is necessary to dissolve the salt, as it is difficult to induce the lime to absorb a larger quantity.