180 
tion in powder 2 
XXII, and xxIII 
Silica, - 
Alumina, SS acene 
Peroxyd of iron, - 
a So 
Magnesia, - = - 
Potash, - 
Soda, 
Volatile, 
XXI. 
4690 47-00 
31-10 
ra ¢ 32°65 
16-07 15-90 
a 
58 
abi} 
1-00 
99-42 
T. S. Hunt on Lithology. 
Xx. XXIII. 
62-05 62°10 
3:96 8-69 
' 24-72 
with the rock of Belceil, seems to con 
een the trachytes and diorites. 
Rigaud mountain consists of a rather 
is made up of a crystalline feld- 
