When the fresh mixture of quick-lime and salt is incorporated with _any porous body_, as soil or peat, then, as Graham has shown, _unequal diffusion_ of the caustic soda and chloride of calcium occurs from the point where they are formed, through the moist porous mass, and the result is, that the small portion of caustic soda which diffuses most rapidly, or the carbonate of soda formed by its speedy union with carbonic acid, is removed from contact with the chloride of calcium. Soda and carbonate of soda are more soluble in water and more strongly alkaline than lime. They, therefore, act on peat more energetically than the latter. It is on account of the formation of soda and carbonate of soda from the lime and salt mixture, that this mixture exerts a more powerful decomposing action than lime alone. Where salt is cheap and wood ashes scarce, the mixture may be employed accordingly to advantage. Of its usefulness we have the testimony of practical men. Says Mr. F. Holbrook of Vermont, (Patent Office Report for 1856, page 193.) "I had a heap of seventy-five half cords of muck mixed with lime in the proportion of a half cord of muck to a bushel of lime. The muck was drawn to the field when wanted in August. A bushel of salt to six bushels of lime was dissolved in water enough to slake the lime down to a fine dry powder, the lime being slaked no faster than wanted, and spread immediately while warm, over the layers of muck, which were about six inches thick; then a coating of lime and so on, until the heap reached the height of five feet, a convenient width, and length enough to embrace the whole quantity of the muck. In about three weeks a powerful decomposition was apparent, and the heap was nicely overhauled, nothing more being done to it till it was loaded the next Spring for spreading. The compost was spread on the plowed surface of a dry sandy loam at the rate of about fifteen cords to the acre, and harrowed in. The land was planted with corn and the crop was more than sixty bushels to the acre." Other writers assert that they "have decomposed with this mixture, spent tan, saw dust, corn stalks, swamp muck, leaves from the woods, indeed every variety of inert substance, and in _much shorter time than it could be done by any other means_." (Working Farmer, Vol. III. p. 280.) Some experiments that have a bearing on the efficacy of this compost will be detailed presently.