120 Lieut. Baddeley on the geognosy 
To judge of the quality ofland by the growth of timber upon 
it merely, is to be guided by the effect, and to lose sight enti- 
rely of the cause 3 apractice, the inconvenience of which, if 
generally adopted, would soon be felt in every department of . 
science. 3 
As the shores of lake St. John are approached, the soil 
gradually becomes sandy, until at Kouispigan, as the mouth 
of La Belle Riviére is called, it becomes one sheet of fine bright 
sand. 
Leaving Kouispigan, we proceeded on lake St. John, to 
the northward, inthe direction of La Grande Décharge, and 
touching at two small rocky islets on our way, collected speé- 
cimens of arock composed almost exclusively of a highly erys- 
talline felspar, of a dark bluish grey colour, but in which a 
little hornblende was present. This rock was observed form- 
ing black isolated masses, both on the shore and in the wa- 
ter, on this side of the lake. Having encamped on one of 
these, at the entrance of La Grande Décharge, we had more 
leasure to consult the characters of this rock, which are as fol- 
lows : it possesses no sign of stratification ; its surface is re- 
markably black, particularly when moistened, and often almost 
semi-metallic : it is frequently flat and tabular ; many portions 
of it attract the needle, although the eye can detect no magnetic 
iron ; its structure is compactly crystalline, in some cases pass 
sing into compact, but there are always to be seen some shining, 
often splendent faces of the laminz, of which it is composed, 
and they are frequently striated. In many respects it bears a 
great resemblance to Labrador felspar, but its iridescence is 
wanting ; it is occasionally traversed by veins of red felspary 
and rarely small portions of its surface were covered witha 
brownish red powder, probably an oxide of iron, One of the 
veins traversing this rock, exhibited a curious phenomenon ; 
the substance of the vein itself, composed of felspar and horn- 
blende, 
