1907-8.] 
Classification of Igneous Rocks. 
151 
64 Groups. 
MgO. 
CaO. 
Na 2 0. 
k 2 o . 
Total. 
Sp. Gr. 
No. of 
Rocks. 
Deviation. 
Si0 2 , etc. 
Total. 
•3 
1-1 
2-4 
1*8 
100-0 
2-64 (2-30) 
10 
1-9 
6-8 
*7 
1-3 
1*5 
32 
99-8 
2-61 
12 
1-0 
5-9 
•3 
•9 
4*2 
3-0 
100-1 
2-65 (2-36) 
21 
1-0 
4-0 
•6 
•7 
2*1 
4-2 
100-0 
2-62 (2-34) 
18 
IT 
6-0 
•3 
1*1 
4*1 
3*5 
100-0 
2-60 (2-35) 
23 
•9 
4-2 
•5 
1*1 
2*7 
4-6 
100-1 
2-61 (2-42) 
17 
1-0 
3-8 
•3 
1*2 
4-0 
3-7 
100-2 
2-64 
19 
IT 
4-9 
•3 
1-4 
2-8 
4-6 
99-9 
2-66 (2-38) 
14 
1-7 
6-5 
•7 
1*4 
4-4 
4-6 
100-2 
2-64 (2-39) 
14 
1-4 
5-9 
1-5 
2'5 
3-1 
38 
ioo-o 
2-67 
13 
1-2 
4-7 
•6 
1-8 
4-5 
4-3 
100-2 
2-63 (2-40) 
29 
IT 
5-0 
1*1 
1-8 
2-9 
5*5 
100-1 
2-66 
20 
1-4 
4-9 
•7 
2-4 
4-9 
4-5 
ioo-o 
2-61 
11 
1-5 
63 
•8 
2-2 
4-6 
6-5 
100*2 
2-60 
11 
1-5 
6-6 
■5 
1-5 
6-1 
6*2 
99-9 
2-75 
10 
1-6 
6-1 
•5 
1*2 
5-8 
8-4 
100-2 
2-60 
6 
2-8 
9-6 
1*4 
3-1 
4-7 
1*5 
100-2 
2-76 
11 
2-1 
10-5 
2*0 
4-5 
32 
2-6 
100*2 
2-64 
16 
IT 
5-5 
•9 
2-3 
5-4 
3-4 
100-2 
2-60 
14 
2-0 
9-7 
2-5 
2-2 
3 3 
3-6 
ioo-o 
2-72 
18 
1-6 
7-5 
1-6 
4-4 
5*0 
2-1 
ioo-o 
2-49 
15 
1-4 
5-9 
• 2-2 
4-7 
3*9 
2-5 
100-3 
2-61 (2'18) 
24 
1-3 
5-3 
1-0 
2 3 
7-2 
2-9 
100-1 
2-72 
15 
1-5 
8-1 
1-1 
2-6 
4-8 
4-7 
100-1 
2-64 
12 
•9 
7-7 
31 
5-8 
4-3 
2-4 
100-1 
2-65 
16 
IT 
5-9 
4-6 
4-8 
3-0 
5*1 
99-8 
2-67 
18 
1-4 
8-7 
1-1 
3-6 
64 
4-4 
100-2 
2-70 
12 
1-2 
7-8 
1-7 
3-0 
5*8 
5*6 
100-2 
2-63 
14 
1-7 
7-7 
•8 
2-4 
8*1 
4*6 
100-1 
2-53 
15 
IT 
5-0 
1*4 
3-0 
5-6 
6’4 
100-2 
2-57 
13 
IT 
4-9 
•4 
1*7 
9-5 
4-9 
99-9 
2-56 
16 
IT 
5*2 
*7 
2-7 
7’5 
6-8 
100-1 
256 
17 
IT 
6*4 
37 
7-4 
3-0 
1-4 
100-1 
2-79 
25 
IT 
6-4 
5-1 
7-7 
2-4 
1-5 
ioo-o 
2-83 
24 
1-6 
8-0 
3-5 
65 
3-8 
1*6 
100-1 
2-88 
16 
1-8 
7'5 
4-8 
5-8 
2-9 
1-1 
99-9 
2-90 
17 
2-3 
9-7 
2-6 
8-5 
3-9 
1*4 
100-4 
2-76 
21 
1-5 
8-5 
4*2 
8-4 
2-9 
1-3 
100-1 
2-82 
14 
1-9 
7-7 
2-6 
64 
4-1 
2*5 
100-1 
2-74 
17 
1-7 
8-9 
3 6 
6*9 
2-7 
2-1 
100-3 
2-93 
15 
1-0 
8*7 
7*1 
8-7 
3-1 
2-1 
100-3 
2-79 
21 
1-4 
7-3 
8-2 
8*9 
1-9 
2-7 
100-4 
2-90 (2-56) 
22 
1-6 
7-6 
56 
9*2 
3-1 
2-1 
100-1 
2-95 (2-65) 
19 
1-0 
5-9 
7-0 
8*4 
2-9 
2*0 
100-1 
2-93 (2-79) 
17 
IT 
5-9 
5-0 
11*1 
4-2 
2*1 
100-6 
2-82 
15 
1-5 
9-4 
6-6 
10-6 
3-1 
1-9 
100-3 
2-91 
18 
1-4 
8T 
2*9 
8*4 
7-5 
3-0 
100-1 
2-76 
19 
2-6 
11-9 
4-2 
93 
33 
5*2 
100-2 
2-78 
15 
1-6 
8-0 
8-9 
9-4 
2-8 
1*2 
99-7 
2-92 
17 
IT 
6-2 
133 
87 
1*6 
•5 
100-1 
2-96 
14 
2-2 
9-7 
5-8 
9'4 
34 
•9 
100-2 
3-02 (2-45) 
16 
1-3 
6-9 
