232 On Mineral Veins. 
for the formation of the mineral veins in the diorite dykes 
found in the schistose rocks. Take, for example, the 
Morning Star Hill, at Wood’s Point, of which Fig. 5 is a 
cross section. 
Fig. 5. : * 
The dyke underlays to the west, and is traversed by a 
series of auriferous quartz veins more or less horizontal, 
situate one below the other, and having no connection with 
each other. Portions of the dyke are frequently enclosed 
within the vein, similar in character to the riders in vertical 
veins. These parallel flat veins could not have been a series 
of open fissures, unless the portions of the dyke between 
them had been suspended by the pressure of the schist on ~ 
each side—a manifestly absurd supposition. | 
The open fissure theory might have been tenable as regards 
some veins, so long as it was held that the contents of these 
veins had been of igneous origin, for the minerals forced into 
the fissure in a molten state might have kept it open, as in 
the case of trap dykes; but when the igneous theory has 
been abandoned, it is inconceivable how geologists can cling 
to a supposition so opposed to all experience. It may 
be urged that when the veins were formed the rocks © 
might have been in such a hard and compact state as — 
