The History of Vesuvius . 
U ul y. 
Lava de Granateilo. 
Lava Staladlite. 
Vesuvius, 1631. 
Vesuvius, 1868. 
Silica 
48'54 
46-58 
Alumina 
14*86 
20 - 00 
Iron peroxide .... 
4 #I 7 
3’20 
Lime 
11*89 
9'°9 
Magnesia 
575 
3-16 
Soda 
2*71 
274 
Potash 
6*45 
7'35 
Iron protoxide 
4*82 
5’ 6 9 
Titanium protoxide 
0*21 
0*2 7 
Manganese protoxide 
ri8 
1*07 
Phosphoric acid ... 
0*18 
Not determined 
Fluorine 
None 
None 
Chlorine 
Not determined 
Not determined 
Water 
0*16 
0*32 
100*92 
99*47 
The same lavas with the constituents grouped according 
to the principle of least paste : — 
Lava de Granateilo. 
Lava Staladtite. 
Leucite 
33-60 
41*80 
Anorthite 
o*6o 
18*20 
Magnetite 
4*45 
3*75 
Olivine 
,.. trace 
— 
Augite 
41*20 
22*6o 
Hornblende ... 
trace 
— 
Nepheline 
... 10*00 
— 
Sodalite 
... trace 
6*04 
Apatite 
0*44 
— 
Paste 
971 
7*6l 
100*00 
100*00 
The percentage composition of the minimum paste in the 
case of the Lava di Granateilo is — 
Silica 45*o 
Lime 27*0 
Protoxides 28*0 
And of the other — 
100*00 
