130 Canadian Record of Science. 
A microscopic examination of sé€tions from lines of shear 
gives proof of immense crushing both of quartz and feldspar, 
though fragments of microperthite have sometimes resisted 
the crushing force and are enfolded by the thin layers. 
Large individuals of quartz are frequently drawn out length- 
wise, broken into many pieces with slightly different orien- 
tation. It should be mentioned that the gneiss as a whole 
presents less evidence of violent strains than the granite. 
The quartzite, which is generally subordinate to the 
gneiss, is white or tinged with red by the weathering of 
some ore of iron, probably pyrite. A little pale greenish 
muscovite, decayed felspar, specks of tourmaline and titanite 
complete the minerals visible without the microscope. In 
thin sections one is struck by the great numbers of rutile 
needles flashing brilliantly between crossed nicols. Thicker 
rods, perhaps of the same nature, are strongly dichroic, 
brown parallel to the chief section of the nicol, almost color- 
less at right angles to it. Hexagonal brown plates are per- 
haps biotite, but seem not dichroic. A few crystals of 
zircon finish the solid inclusions. Cavities, often crystalline 
in outline, contain the same fluids as were found in quartz 
from the granite and gneiss; though these cavities, as well 
as the rutile prisms are much larger than in the other rocks. 
The only crystal of apatite observed was thick like that 
from the granite. Cataclase structure is less strongly 
marked than in either of the other rocks. 
In reviewing the three rocks described one is struck by 
the points of relationship between them rather than by their 
differences. They must have been formed under certain 
common conditions; for salt water, carbonic acid under 
great pressure and oxide of titanium are found in the quartz 
of all three. Every constituent mineral of the two schis- 
tose rocks, except a few scales of muscovite in the quartzite, 
is found in the granite, which may be looked on in a sense 
as forming a mean between them. If the various kinds of 
gneiss and quartzite were blended together, a rock very like 
the granite would result. It was intended to make a series 
of analyses to test this chemically, but time to carry out 
this purpose has failed. 
