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No. 200.] 203 
of lime, but as the effects are not so palpable, it is sufficient for my pur- 
pose to refer to them. Phosphate of lime is also produced, or found 
in lavas, particularly those in Spain. 
Again; the sandstone, in contact with this variety of limestone, has 
been converted into well characterized hornstone; that is, a rock which 
is always composed and made up of granular particles, and is evidently 
of mechanical origin, is found, when in close proximity to this lime- 
stone, a perfect hornstone with all its translucency and toughness, con- 
choidal fracture, and sharp cutting edges. Such is the change, and if 
the adjacent rock was granite, no one would now hesitate to ascribe the 
change to the granite. A specimen of the hornstone is in the collec- 
tion, and the locality from which it was taken is near the village of De 
Kalb. It is rare to meet with these rocks in contact; I do not remem- 
ber to have seen another instance than the one here mentioned. 
In concluding my remarks on the subject of the limestone of St. 
Lawrence, I remark, that if I have failed in establishing its want of 
stratification, and that it is like granite, of igneous origin, still I 
think it will be admitted that the views and considerations I have pre- 
sented are at least plausible. 
If the phenomena of granitic veins have obtained for this rock a 
rank, or place, among the igneous products of the globe, why may not 
the same phenomena obtain for limestone the same rank and place. If 
not, how shall we account for the presence of branching irregular veins. 
How were they produced ! An inference which is legitimate in one 
instance must be so in another, where the facts are the same; and if ge- 
ologists are right in maintaining the igneous origin of granite or green- 
stone, I do not see how they can refuse to admit limestome a member 
of the igneous family. 
Mditimal remarks on the economical uses of the 'primitive limestones. 
The economical uses to which the granular or primitive limestone 
may be applied are three. 1. When sufficiently free from the hard 
imbedded minerals and sulphurets, it forms a tolerable marble; but it is 
not equal to transition marbles, either in beauty, texture, or durability. 
The most promising localities for this material are between Rossie and 
Gouverneur, and on the farm of Judge Streeter, in the latter place. Its 
coarseness is a great injury to it as a building material, either in or out 
of doors, and it appears also to be more liable to discolorations by the 
oxides and sulphurets of the metals, and also to the attachment of li- 
chens, or minute plants. 
