120 Scientific Intelligence. 
an additional percentage of the oxyds from a former higher surface now 
eroded, and with this extra charge of iron and manganese carried by per- 
colation down to and crystallized against their foot tock,—this change 
may have required an immense time to erfect, and no doubt was going r 
with the disintegration and recrystallization be un, to the perfect ball’ 
and pot ore of radiated, acicular, crystallized brown-hematite. The great 
variety in the composition of the original rocks has been the cause of a 
great diversity in the ores taken from the different openings. But two \ 
principal distinctions may be particularly noticed; viz: that the ores = i 
Ww 
to hold a small percentage of sulphur; or perhaps we should say, are less 
likely to permit the abundant drainage needful for carrying off the sul- 
phur in the form of a salt. Sometimes in the same deposit there is a 
mixture of the two varieties, producing a neutral ore, ut it is 
often that such large exposures of both varieties occur in the same 
neighborhood, as is the case here. 
* Taking into view all that we know of these deposits along the southeast 
side of the Great Valley from the Hudson river to Tennessee and Alabama, 
and adding what we know of similar deposits, produced in a similar way, 
Mr. Lesley also describes the positions of the lignite beds, and refers 
them to the Tertiary age, as done by Lesquereux (though without men- 
is point atforded b ont 
sion over these regions to the New Red Sandstone Triassico-Jurassic 
of the Atlantic slope, as follows -— pie 
