No 50.] 
47 
different associations and the mode in which they are distributed in 
different countries. These researches, although in part appertaining 
to Geology, when exclusively confined to simple minerals, form also 
an important part of descriptive mineralogy. 
In examining the localities of the various mineral species and varie- 
ties we find great diversity in the appearances which they present. 
Minerals in a few cases constitute mountain masses ; such for example 
as serpentine, carbonate of lime, dolomite, pyroxene, hornblende, and 
even magnetic iron ore. In other cases, they occur in beds, blocks or 
veins, such as most of the metallic minerals, and calcareous spar, in its 
crystallized form. Finally, other minerals are disseminated in quanti- 
ties through masses of rocks, or in the rifts and cavities which they 
contain. 
Those who have but partially studied the mineralogy of the State of 
New-York, cannot fail to have noticed the similarity which in this re- 
spect exists between its northern and southern portions. To such 
northern district belong parts of the counties of Clinton, Franklir^, St. 
Lawrence, Jefferson, Lewis, Herkimer, Hamilton, Essex and Warren; 
while the southern includes parts of the counties of Orange, Rockland, 
Westchester, Putnam, Dutchess and Sidlivan. I refer especially to 
the general nature of the rock formations, and to the minerals which 
are imbedded in them. The most interesting and important of these 
minerals, now knowii, are undoubtedly the various kinds of iron ore. 
Let us see how far the statement above made in regard to the similarity 
in the northern and southern portions of the State, is supported by the 
facts which we possess concerning these valuable productions. 
Northern Counties. — The magnetic iron ore is almost as exten- 
sively diffused as are the mountains of granite and gneiss throughout 
the comities of Warren, Essex, Clinton, and Franklin. The rocks in 
which the ore is found in these counties, however, difi'er somewhat in 
their characters. In some parts of Essex, it is associated with a rock 
composed of quartz and hornblende, of a fine granular structure, but 
the most extensive beds in this county are associated with a granite or 
sienite composed almost entirely of dark coloured feldspar, containing 
masses of opalescent or Labrador feldspar, and in some places a small 
proportion of augite or pyroxene. In Clinton county the rock in which 
this ore is found is a granite composed of quartz and feldspar, quartz 
and hornblende, or feldspar and hornblende, sometimes with scales 
