128 Canadian Record of Science. 
At a distance from these well defined fragments one finds 
here and there in the granite darker, finer grained spots 
with no distinct boundary, probably bits of gneiss more 
strongly acted upon. Here the gneissoid structure can 
scarcely be recognized, and it may be that some examples 
showing much of a bluish green augite under the micros- 
cope were torn from some deep seated augitic rock not 
found at the surface. 
The granite is in general monotonously red and coarse 
grained, though finer grained portions occur, and the color 
sometimes bleaches to a bluish or purplish grey. It has 
been quarried for various purposes, and specimens prepared 
in Mr. Forsyth’s stone cutting establishment in Montreal 
display a rich color and fine polish. 
Rare veins in the granite or gneiss contain black tourma- 
line regularly intergrown with quartz, or crystals of grey- 
ish perthite with cleavage surfaces a foot across, graphic 
granite (an intergrowth of quartz and perthite), and mas- 
sive quartz. 
Under the microscope the usual constituents of granites 
in Ontario present themselves, quartz, potash felspars and 
and biotite frequently accompanied by hornblende. The 
rock is then a biotite hornblende granite. 
The quartz is of the usual kind, crowded with fluid cavi- 
ties, often ‘‘ negative crystals” in form, containing carbonic 
acid or water with a cube of salt. Innumerable minute 
needles which are highly refractive and in isotropic quartz 
sections show parallel extinction, are probably rutile. 
The felspars include a little orthoclase, microcline in much 
larger amounts generally with microperthitic inclusions, 
and a small quantity of ordinary plagioclase with a low 
angle of extinction from the twin plane. Micropegmatite 
in which quartz forms wormlike inclusions in felspar is very 
common. 
The biotite is brown, though more or less weathered into 
greenish choloritic products, and the green hornblende is 
still more often decayed. With these minerals are gener- 
ally found brown titanite in large amounts, as well as the 
