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 
at one time covering or sustaining 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 difficulty ; 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 Middlefields, west of 
Middletown, with impressions of fish, i dary. Slate then 
appears to belong to all these three great classes of rocks. 
As to the meialliferous 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 tofthe perusal of those who 
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. 
