70 Eaton's Key, 



of Bakewell, and some of his own. Werner's arrangement of 

 rocks has, undoubtedly, its imperfections and its redundancies ; 

 and yet it may be questioned how far his system has been 

 really improved by its different emendators. If Werner, by 

 mentioning argillaceous schistus only in the primitive class of 

 rocks, left us to dispose of it where we might, when we find it 

 atone time, covering or su^aining anthracite, with impressions 

 of ferns, and at another with impressions of fish and vegeta- 

 bles, and in contact with bituminous coal ; still those who, with 

 Mr. Eaton, throw argillaceous slate into the transition class, and 

 omit it in the primitive and secondary, embarrass us with an 

 equal difl5culty ; for we find argillaceous slate in contact, and 

 alternating with, mica slate, and without any impressions of 

 organized bodies, when we must, without a doubt, call it pri- 

 mitive. 



This is the fact with the clay slate of the Woodbridge hills, 

 near New-Haven, which is primitive ; that of Rhode-Island, 

 with anthracite, is transition ; and that at MiddlefieldSj west of 

 Middletown, with impressions of fish, is secondary. Slate thea 

 appears to belong to all these three great classes of rocks. 



As to the metalliferous limestone, we do not so much object 

 to the introduction of this term by Bakewell, although it ap- 

 pears to us quite as well to say that certain limestones, those 

 of the transition class for example, are metalliferous. But is 

 Eaton correct in referring such limestone as that of which the 

 New-York City-Hall is built, to a metalliferous class ? Is not 

 that limestone decidedly primitive ? The fact mentioned of 

 its containing pyrites, hardly proves it to be metalliferous ; 

 since most rocks contain more or less of pyrites. Some other 

 remarks of less importance we might add, but we prefer con- 

 cluding by recommending this tract to the perusal of those %vho 

 wish for information respecting the geological structure of 

 New-England ; and we think that Mr. Eaton is seriously 

 aiding the progress of geology in the interior of New-England. 



