No. 161.] 109 
search of coal, gold or silver, when a very limited knowledge of 
the subject would have saved the useless expense. 
We shall now speak of the individual rocks of the 2d district, 
confining ourselves to their general characters and the use to which 
they may be applied. 
1st. Granite. For the present, we apply this name to the rocks 
in the interior of Essex, as it is the one which appears at the high- 
est elevation, and constitutes the great primitive nucleus, towards 
which all the other primary rocks lean. This rock is not strickly 
speaking granite ; that is, it is not composed of quartz, feldspar 
and mica, neither is it a true sienite, for even the hornblende dis- 
appears almost entirely for miles. It is mostly feldspar in every 
locality where the formation is perfectly developed. This feldspa- 
thic rock, to adopt a descriptive name, contains the beautiful La- 
brador feldspar; it is often in large masses, and might be obtained, 
probably, of sufficient size to form small ornamental tables. The 
colour of the rock is usually grey, greenish or bluish, and in small 
pieces frequently pale green and bluish green. It rarely contains 
quartz. The coarse granites, like those of New-England, have no 
where been met with. There is a fine reddish granite in the Kay- 
aderosseras range, and also a coarse granite bordering the St. Law- 
rence, in the town of Alexandria, and also forming the Thousand 
Islands. The latter often contains beds of feldspar nearly white, 
and suitable for the manufacture of porcelain. The most valuable 
bed is on an island in the St. Lawrence, opposite Alexandria. It 
is called by way of distinction High Island, though it does not rise 
more than fifty feet above the water. A specimen or two of this 
feldspar may be seen in the collection. 
The feldspathic rock of which we have spoken, has not been ex- 
amined in place, except in Essex county; there it forms mountain 
masses, and attains a great elevation, as will be seen by reference 
to our accounts of the measurements given in the preceding pages. 
These mountains slope rapidly to the north and soon disappear un- 
der the transition rocks in Clinton county; they are not supposed 
to rise again till they reach Labrador. In this country the rock 
probably appears bearing the same minerals as in Essex county. 
Travelling north from Caldwell to Moriah we meet many boul- 
ders of this rock by the road sides, particularly in Warrensburgh, 
