254 Messrs. Jackson and Alger on the 
allel to the lateral primary planes of the crystals, though they 
present deep transverse striz which seem to indicate an opposite 
cleavage, and which are not stated to have been observed in the 
crystals of that mineral; from which also it differs, in not being ta- 
ken up in the smallest degree by nitric acid. The secondary 
planes of the crystals of this mineral, are usually more smooth 
and vitreous than the primary, which are roughened by strie ; 
and they disclose a perfectly transparent and homogeneous inte- 
rior. These crystals are rarely three eighths of an inch in length. 
But we shall suspend any further remarks on this substance, until 
an accurate and careful analysis of it, now making by our friend, 
Mr. A. A. Hayes, is completed ; as we may then be better able to 
show its identity with any partially known species, or set forth 
its claims to the title of one wholly unknown to the present cata- 
logue of mineral substances. We were unwilling to pass on, 
without recording some notice of it, although we have not given 
a complete description of its characters, and have attempted only 
to identify it with some described species. 
Hornstone, masses of agate, &c., occur scattered among the 
ruins of the trap rocks, which become entirely inaccessible as 
we approach Cape Blomidon. This cape forms an abrupt termi- 
nation of the North mountains, or, as they are called in this dis- 
trict, the Cornwallis mountains, on the east. It presents us with 
a view of the outcropping of the sandstone, which here gives sup- 
port to the trap rocks, and constitutes the chief part of the 
precipice, being more than three hundred feet high, and having 
the columnar trap resting upon, and scarcely attaining the eleva- 
tion of an hundred feet above it. ‘The sandstone forms a pro- 
jection beyond the trap, which is called by the inhabitants of the 
country “the offset.” This rock is regularly stratified, and dip- 
