a!* ^ 
THE MEDITERRANEAN NATURALIST 
and near the Observatory. Everything was new/ 
dark, as the mountain had calmed down at 8 p.m. 
At 2 a. m. June 8th, we were at the extremity 
of the Observatory ridge and commenced to wend 
our way across the lava surface towards Monte 
Semina. We were at the lowest part of the 
depression at the W. and of the A trio del Cavallo 
where it joins the Fossa dells Vetrana and along 
which some of the largest lava streams have ; 
flowed ( 1855, 1872, etc. ) when suddenly on our 
right, above us (2.23a.m.) avast quantity 
of bright red vapour arose from the new outpour 
of lava and which Illuminated all the wild crag j 
o the inner walls of Monte Somma. We hast- ■ 
ened our steps as much as the road arid ou Ian 
tern would allow us, so as to reach the escarq 
ment of Monte Somma, the foot of which was 
followed till near the Punta del asone and 
close to the theatre of eruption. Here we tim- 
bered up some distance above the level of the 
Atrio to watch events whilst we ate our late : 
supper or early breakfast. Along the slope of 
the great cone in the line of fissure were a Tv 
luminous points from a few pieces of still un- 
cooled lava of the little that had oozed forth 
from the lower half of the fissure. At about GO 
or 80 yards from the foot of the great cone two 
or three fountains of lava were throwing up jets 
of molten rock for 2 or 3 m. and the lava was 
slowly spreading out on the almost horizontal 
plain of the Atrio in several tongues. The lava 
must have still been high in the maim chimney, 
as the vapour that issued at the top of the fissure 
showed slightly the illumination. So we remained 
till daylight when we could see the fissure on the 
side of the cone. The mouth that formed at 
5.30 the previous day was still smoking a little, 
whilst the fissure below it sent off several rami- 
fications at an acute angle like the branches of 
an inverted tree from several of which, little 
streams of lava had been given out, where they 
had soon consolidated. We now followed the 
base of the great cone to the lower rail 'wav sta- 
tion, where we found all the people up and 
dressed, frightened by the strong shock and 
noises at 2. 23 a. m. coincident with the fresh 
outflow of iava that we had witnessed, but which 
shocks we had not felt, although they were des- 
cribed as the strongest that had occurred. 
Having ascended the summit of T v esuvius we 
found the central crater rapidly enlarging by the 
falling in of its edges. From the new fissure at 
its summit was issuing much vapour under pres- 
sure, and so rich in Sulphurous acid as even in 
traces to be intolerable; and the hot air coming 
from innumerable new fissures rendered approach 
very difficult. We did in fact once jump across 
part of the fissure, but returned much quick er on 
account of the hot irritant vapours. An approa*. h 
from the opposite side was equally unsuccessful. 
At some old futnaroles on the 1872 crater plain 
I collected some crust of Boric acid, and alum, both 
rare products at this volcano. 
One of three terminations we may expect to 
these phenomena which are very characteristic of 
a lateral disruption so common at Vesuvius : 
1st. Should the lava cool sufficiently to plug the 
radial dyke no further phenomena will occur, 
and activity will be restored to the central vent. 
2nd. If this plugging only partially take place 
lava may dribble forth for months, but probably 
the escape of vapour will soon be restored 
to the central vent. 
3rd. If the rent should widen, considering how low 
it extends we may expect a grand eruption 
which might rival that of 1872, which com- 
menced near the .same spot and much in the 
same way: the mechanism by which this occurs 
I have explained elsewhere. (1) 
H. J. Johnston-Lavis. 
Observations on the Geology of the 
Maltese Islands 
by John H. Cooke 
The Maltese Islands have of late years oc- 
cupied a considerable share of the attention of 
naturalists, and they are, therefore, by no means 
a terra incognita either to the botanist or to the 
geologist. 
But while the botany of the Islands has been 
making most marked progress in the hands of the 
late Professor Gulia and his collaborators, the 
(1) If. J. J. L. The Relation-ship of the Struc- 
ture of Igneous Rocks to the Conditions of their 
Formation . — Scieniif. Proceed. R. Dublin Soc. 
y.ol. V, New Ser. pp. 112-156. 
