This is an important fact. Lime may act beneficially on many or most soils by converting the soda silicate into a lime silicate, or, in other words, converting a salt that will not absorb carbonate of ammonia from the air, into a salt that has this important property. There is no manure that has been so extensively used, and with such general success as lime, and yet, “who among us,” remarks Prof. Way, “can say that he perfectly understands the mode in which lime acts?” We are told that lime sweetens the soil, by neutralizing any acid character that it may possess; that it assists the decomposition of inert organic matters, and therefore increases the supply of vegetable food to plants: that it decomposes the remains of ancient rocks containing potash, soda, magnesia, etc., occurring in most soils, and that at the same time it liberates silica from these rocks; and lastly, that lime is one of the substances found uniformly and in considerable quantity in the ashes of plants, that therefore its application may be beneficial simply as furnishing a material indispensable to the substance of a plant. These explanations are no doubt good as far as they go, but experience furnishes many facts which cannot be explained by any one, or all, of these suppositions. Lime, we all know, does much good on soils abounding in organic matter, and so it frequently does on soils almost destitute of it. It may liberate potash, soda, silica, etc., from clay soils, but the application of potash, soda, and silica has little beneficial effect on the soil, and therefore we cannot account for the action of lime on the supposition that it renders the potash, soda, etc., of the soil available to plants. Furthermore, lime effects great good on soils abounding in salts of lime, and therefore it cannot be that it operates as a source of lime for the structure of the plant. None of the existing theories, therefore, satisfactorily account for the action of lime. Prof. Way’s views are most consistent with the facts of practical experience; but they are confessedly hypothetical; and his more recent investigations do not confirm the idea that lime acts beneficially by converting the soda silicate into the lime silicate. Thus, six soils were treated with lime water until they had absorbed from one and a half to two per cent of their weight of lime. This, supposing the soil to be six inches deep, would be at the rate of about 300 bushels of lime per acre. The amount of ammonia in the soil was determined before liming, after liming, and then after being exposed to the fumes of carbonate ammonia until it had absorbed as much as it would. The following table exhibits the results: