30 Mineral Resources of JVew York. [July, 



racters which show that they were derived from preexisting masses 

 which had been ah-eady consolidated: but what is still more im- 

 portant, and what is particularly interesting, is, that in this sys- 

 tem, organic bodies first make their appearance; that during their 

 formation life, in its humbler condition, was first manifested, the 

 dawning of which indicated the future development and power of 

 a new order and kind. The third, or silurian, sometimes called 

 also the New-York system, is well distinguished from the pre- 

 ceding by the great abundance of organic bodies, belonging both 

 to the animal and vegetable kingdoms, all of w^hich, however, are 

 forms ranking low in the scale of organic existence; and it is only 

 in the superior part that we find unequivocal evidence of the su- 

 perior grade to which life seemed to be tending in the remains of 

 fish, which the strata are now known to enclose. The fourth sys- 

 tem in New- York is called Devonian, or old red; and seems to 

 be scarcely more than the prolongation of the silurian; for while 

 all the typical forms go up into it from the silurian, no decidedly 

 new types or forms have yet been discovered, except in the ichthyo- 

 lites or remains of fishes. Many new species and genera it is 

 true are found in the Devonian which are not known in the silu- 

 rian; yet, it is scarcely possible to discover that they belong to 

 new types, or are very far removed from the mollusca and conchi- 

 fera of the silurian. These general remarks are introduced for 

 the purpose of opening the way for pointing out what is peculiar 

 to each system, and what useful materials belong to each respec- 

 tively; and also in what part of each system the valuable pro- 

 ducts belong. 



We begin w^ith the primary system and proceed in the ascend- 

 ing order. In the first place to what use may the rocks them- 

 selves be applied? In answer to this question we may remark, 

 that the primary formations in New York are somewhat peculiar. 

 The stratified rocks, such as gneiss, mica slate and hornblende, and 

 which in New England are fissile, and form good flagging and 

 good fire stone, are generally defective in those qualities which 

 render them suitable for construction, except for the most com- 

 mon purposes. In that part of New York north of the Mohawk 



