260 FERTILIZEM. 



than anthracite coal ashes ; indeed, abating the quantity of earth which is necessarily intermixed 

 witli peat ashes, I can see no reason wl>y they should not be nearly equal in value to wood 

 ashes, inasmuch as they are derived from vegetable matter. In some parts of New- York, par- 

 ticularly in that tract of country extending from Rome to Syracuse, peat ashi i  ^^ht be manu- 

 factured expressly for fertilization. Heaps of peat might be made, and, after drying, burned upon 

 the field, and their ashes spread. Tlie whole operation would be attended with lit'' • xpense. 

 Ash obtained in this mode will be intermixed with much charcoal, or peat imjy«.wci.i.ly con- 

 sumed, which, in itself, will become valuable in promoting a rank vegetation. Allied both to 

 charcoal and ashes, is soot : it is esteemed as a valuable fertilizer abroad. Imperfectly burned 

 wood or coal rises in vapor and smoke, from the burning substance, which is deposited in the 

 flues and chimneys. Soot is quite as complex in its composition as ashes ; indeed it is proba- 

 bly more variable, and we find one element which is not present in ash, namely, ammonia. 

 Phosphates and sulphates, together with carbonates, of lime, soda, potash, iron and magnesia, 

 are the principal constituents. Soot will be applied in a diluted state, as a top dressing, and 

 may be used to the extent of thirty or forty bushels to the acre : very few instances, however, 

 are known of its use, in this country, on so large a scale. 



7. Crushed and Ground Rocks. 



To what extent crushed granite, or slates and shales, may be used with profit, as fertilizers, 

 has not as yet been determined. That a soil is benefited by the application of ground rocks, 

 there can be no doubt. In England crushed granites are employed for the sake of potash, and 

 probably the phosphates are also contained in them. I have ascertained that some of the shales 

 and slates of our sedimentary rocks contain fertilizers, which, under favorable circumstances, 

 might be employed. The profits of such application turn much upon the accessibility of the 

 substances. All that I can say upon this subject, is, that where a farmer finds crumbling rocks 

 upon his premises, it indicates the presence of alkalies, or the sulphurets : if the latter are pre- 

 sent astringent salts are usually produced. Long exposure to the weather, however, prepares 

 even these salts for his fields ; or, the application of lime will form, with them, almost imme- 

 diately, a valuable fertilizer. All the changes which the weather produces upon rocks should 

 be noticed, as from those changes the farmer will derive many valuable hints. I suspect that 

 if the layers of the different groups of rocks were carefully analyzed, that some of them would 

 be found to contain valuable fertilizers, in constant, though small proportions. Rocks which 

 are suspected to contain potash, might, when crushed, be mixed with quicklime, in order to 

 hasten the process of decomposition. Those granites which offer the best prospect of yielding 

 the alkalies are coarse grained, and contain felspar in excess. The localities at which these 

 granites occur in the State of New-York are limited : Johnsburgh and Minerva lie in a limited 

 belt, where decomposing granites are common. The primary of the northern interior consists 

 of hypersthene rock, which contains lime, mostly as a substitute for potash. In the southern 

 highlands, the rock is mostly gneiss of a firm texture, and only slightly inclined to disintegra- 

 tion. The greenstone trap offers the best prospect of furnishing potash. 



