1907-8.] Classification of Igneous Rocks. 153 
— continued. 
MgO. 
CaO. 
Na 2 0. 
K a O. 
Total. 
Sp. Gr. 
No. of 
Rocks. 
Deviation. 
Si0 2 , etc. 
Total. 
10-1 
7*4 
1*7 
1*1 
99-7 
3-13 (2-56) 
8 
3 0 
13-9 
6-6 
12*4 
3*0 
1-5 
100-3 
2-95 
19 
1-4 
7-2 
9-1 
11-6 
2*5 
•9 
100-4 
3-00 
13 
1-6 
6-9 
5 3 
10-8 
3-6 
1*4 
100-1 
3-12 (2-40) 
19 
1-6 
8-5 
6-7 
10-6 
2*8 
1-3 
100-3 
3-08 
15 
3-0 
10-9 
26-8 
6-8 
•2 
•2 
99-3 
3-25 
7 
3-0 
10-0 
41-2 
2-3 
•5 
•1 
100-5 
3-20 
10 
1-8 
io-i 
22-0 
6-8 
1-1 
•8 
100-1 
3-16 
12 
1-6 
8-6 
29-3 
3-8 
•2 
•2 
99-4 
3-00? 
45 
3-8 
12-0 
12-7 
14-3 
2-1 
1*1 
100-0 
3-09 
14 
1-9 
10-9 
16-6 
12-0 
1*8 
1*6 
100-2 
2-95 
13 
1-9 
12-3 
10-9 
13*3 
3-3 
1*4 
100-2 
3-25 
14 
1-8 
8-8 
12-4 
12*0 
2-9 
1*5 
100-4 
3-06 
13 
2-2 
10-9 
4-6 
5-8 
3*7 
2-9 
100-1 
2*80 (2-44) 
1000 
7-3 
