LIMESTONE IN AGRICULTURE. 
65 
Galena, blende, and pyritous copper; zircon, in fine perfect translucent crystals from 
one-tenth to two inches in length, at Rossie. 
Condrodite, in Schroon. 
Graphite is universally disseminated in the rock. 
It is a curious fact, that the ores of iron, which are contained in this rock, are in a state of 
peroxidation. In St. Lawrence county, where this rock is so abundant, the black ores of iron 
are quite uncommon. 
Value of Limestone in Agriculture. 
Some experiments have been made with this rock, to test its value as a fertilizing agent, 
but the results have not been very satisfactory. According to the opinion of some farmers, 
it exerts a favorable influence ; but according to others, it has little or no effect. Such would 
very probably be the result where but few had tested this question; for it is always to be 
expected that the circumstances or condition of the ground might determine the result, and 
which might be unsuccessful in a few instances, and yet, upon the whole, prove a valuable 
agent in increasing the productiveness of some kinds of soil. It is the opinion of many of 
the best informed agriculturalists, that lime is quite essential to fertility. If this view is cor¬ 
rect, then no reason can be offered why the unburnt limestone should not be useful; for, the 
state in which it exists in all soils, must be that of a carbonate. A reason why it appears to 
have no effect, may be its want of fineness, and its slow operation. Marl, which is an ar¬ 
gillaceous carbonate of lime, is extremely fine : this is usually esteemed in agriculture, and of 
its value there can be no doubt. I think, upon the whole, from all the testimony I can collect, 
that the unburnt limestone will prove valuable in agriculture, if it is reduced to the fineness 
of the marls, many of which are nearly a pure carbonate of lime. If this conclusion is in¬ 
correct, then it will be necessary to give up the prevailing opinion that lime is an essential 
element in good soils. 
Some important inquiries, which follow from the establishment of the igneous origin of 
Primitive Limestone. 
It has been my object to place before, the reader all the facts relating to the occurrence of 
this rock ; the precise relation which it holds to other masses ; and also to give a general 
view of its extent, and of the proportion of surface which it bears to other rocks. How it 
occurs among those rocks, may be seen from the structure of the diagrams which I have 
used for illustrating this important point; but, it is only by a careful examination in the field, 
that the student can acquire perfectly correct notions of this rock, and divest himself of the 
prevalent doctrine, that it is only a sedimentary mass, changed in some places by igneous 
action. When, however, he sees its position among the schistose, as well as the thick un¬ 
stratified rocks, he will perceive the insurmountable difficulties to the maintenance of this 
doctrine; and not till then will the more simple and rational one which I have endeavored to 
support, be likely to gain his credence. Against this view, I am sensible that there is, if I 
Geol. 2r) Dist. 9 
