166 Jounston-Lavis—The Eruption of Vesuvius in April, 1906. 
convenience the other products are also placed in parallel columns, and will be 
discussed when we come to their description :— 
AwALyses oF Lavas AND oTHER EsyecTA or Vesuvius in Aprit, 1906. 
Sel: 2. 3. 4. 5. 6. 
ees Lacroix. Lacrorx. LAcroIx. CASORIA. CasoRIA. 
FiscuTen. 
Laya of Bosco- Lava of Cog- Grey sand Reddish sand 
| __trecase. | Scoria at com- | noli, 8 Ap., Essential (near Obser- | (near Obser- 
MAINO) Geese, [iLleeree| Gane, | weaker | Wed” 
Si0, 47°644 47:50 48°28 48:10 48°117 48°154 
Al,0; 18°671 18°59 18°39 15°31 19:082 18°437 
Fe,0; 3511 1°52 1:12 3°20 7:709 7565 
FeO 5854 7°62 7°88 5°45 PRP 2°750 
MgO 3°924 3°86 3°72 7°55 3°728 4:432 
CaO 8°337 9°16 9:20 12°45 7:949 8244 
Na,O 2°310 2°72 2°84 1:98 2°528 2°871 
K,0 7:099 7:05 7:25 4:22 6°403 5'°834 
TiO, 0:767 1:05 1:28 1:15 undet. undet. 
P.O; 0:802 tr. 0:51 | 0:12 0°852 0:748 
H,O —- | 1°25 062 | 0:87 = = 
ZrO, = == —_ a ae gly 
BaO 0:177 — a= — 0:0938 0-096 
MnO 0:762 =| —- — — 0:418 0°394 
SrO — — _- — 0:028 0:0338 
99°828 100°32 101-09 100°40 99:679 99°552 
FRAGMENTARY EJECTA. 
Practically no part of the slopes of Vesuvius, or the immediate neighbour- 
hood of the mountain, escaped receiving some of the fragmentary matter shot forth 
from the voleano. To describe in detail a large number of sections would make 
this memoir too long; and I have, therefore, endeavoured to give a series, chosen 
from those regions that received the more important showers of stones and dust, 
and specially those that illustrate the mechanism of the eruption, or were the 
