316 Messrs. Jackson and Alger on the 
river, exhales in sultry weather, an odor, which cannot fail to 
apprize the inhabitants of its existence. 
About four miles from Bear river, in the vicinity of a place 
known as “The Joggins,” the clay-siate of the South mountains 
is intersected by another dyke of porphyry, which is here pre- 
sented, forming the sides of a deep recess or valley, but a few 
yards from the main road to Digby. It enters the strata nearly at 
the same angle with the dyke, before mentioned, on Nictau moun- | 
tain; and, like that, its actual connexion with the neighbouring 
slate being entirely hidden from observation, we were unable to 
determine its extent, or its more approximate relations to that 
rock. The base of this porphyry is a greyish-black trap, of a 
fine-grained texture, and compact. The imbedded granular con- 
cretions of felspar, of a pure white color, are very numerous. 
Though, for the most part, no regularity of form is discernible in 
them, sometimes distinct parallelograms of white felspar may be 
observed. The rock is thus rendered more distinctly porphy- 
ritic than that of Nictau. | 
We shall not attempt to discuss the origin of the dykes which 
thus intersect the strata of clay-slate ; for the theory applied to all 
other dykes of similar character, is equally applicable to these. 
They are doubtless of an origin posterior to the clay-slate, and now 
occupy the immense fissures left by the contraction or solidifica- 
tion of the adjoining transition rock, including the great ore-bed ; 
and have proceeded from, or are coeval with, the trap rocks of the 
neighbouring North mountains. Should the dyke at this place 
extend for any considerable distance into the high land, it will be 
found most probably to intersect the great ore-bed, which, from 
the direction of the latter near Bear river, must take place nearly 
two miles south of the valley. Whether the intersection does 
