260 
FERTILIZERS. 
than anthracite coal ashes ■ indeed, abating the quantity of earth which is necessarily intermixed 
with peat ashes, I can see no reason why 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 ask might be manu¬ 
factured expressly for fertilization. Heaps of peat might be made, and, after dry mg, burned upon 
the field, and their ashes spread. The whole operation would be attended with liti 1 " expense. 
Ash obtained in this mode will be intermixed with much charcoal, or peat imp^nccdy 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 
e 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. 
