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Emmons on American Geology. 405 
_and it is now well known that the lead-bearing limestone of these 
regions rests upon the ‘T'renton limestone and is overlaid by the 
Hudson River group. The lead mines of Missouri however oc- 
eur in the Calciferous sandrock. 
“In his description of the copper mine of Bristol, Conn., we are 
told by Mr. Emmons that the ore is gray copper, with yellow 
sulphuret, and that the locality is remarkable for its fine crystals 
of gray copper. The crystals of copper-glance or vitreous copper 
ore from this mine are well known to mineralogists, but gray 
copper, (fahlerz) which Emmons confounds with this species, is 
a very rare ore in this country, and has never yet been found at 
Bristol. He also informs us that Chatham Co.,N. C., affords veins 
of gray copper (coppe r-glance, ) ‘ which is probably an altered yel- 
low sulphuret.” But this is not the only instance where his min- 
eralogy is at fault; on page 53, leucite is classed with the zeo- 
lites, although it isa feldspar and has no affinities with that class. 
Steatite i is said by our author scarcely to differ from tale ; but the 
only analysis given in the illustration of this similarity, is the 
following,—Silica 48-30, magnesia 26°65, oxyd of iron 2-00, alu- 
mina 6°18, and water 9: 05, which is the composition of saponite ; 
the true steatites contain upwards of 60 p. ec. of silica, with but 
little water and no alumina. 
Mr. Emmons’s zodlogy is however still worse than his miner- 
alogy. We quote a few samples from a glossary of scientific 
terms soyenied to his report on the Geological Survey of North 
Carolina, 1852 
Dhaka: fossil of a cylindrical form, tapering rapidly to a 
point, and at one end or the other it has a conical cavity ; it is the back- 
bone of an extinct animal allied to the cutile fish bh; 
* Mammalia—animals which furnish glands for the secretion of 
si 
** Mastodon—see mammoth. 
“ Mammoth—an so thick. skinned animal allied to the elephant.” 
He thus confounds the two distinct genera Mastodon and E'le- 
phas. And these we are ashamed to say, are from the pen of a 
man, who is now, and has been for sary years, Professor of Nat- 
ural History i in an American col 
Whatever else may be objected our author, it must be con- 
ceded, ‘that in endeavoring to enliven the technicalities of geology 
by excursions into other - si does not peor pan . acre 
red sciences, 
des with eet. from kin diate for i iotedittngs ia En- 
bri 
ing pines, wherens ieind or wave can move them, or bring up 
