232 Hague and Iddings— Volcanoes of 
cones. 
TABLE III. 
; Til. 
SiO. 69°36 65°77 "6°75 
Al,O; 16°23 21°51 12°32 
Fe,0, 88 
FeO 1:53 trace 1°36 
CaO 3°17 6°42 1°18 
MgO 1°34 0-00 0°00 
Na,O ‘06 5°92 3°55 
2 3°02 0°83 3°98 
Ignition 0°45 0°34 0°54 
100°04 100°09 99°68 
The analysis itself would indicate that the rock belonged to 
the dacites, for in addition to the increase in silica there 1s 40 
