THE MEDITERRANEAN NATURALIST 
337 
Notes and News. 
The island of Samothrace has, according to an 
Athenian telegram, been visited by a severe earth- 
quake the effects of which have been as destructive 
to property as were those of Zante. 
In our next number we shall give our readers a 
detailed account of the more prominent physical 
phenomena with which the Zantiote earthquakes 
were accompanied. 
About this time last year we had occasion to 
refer to the remarkable fact that many of the 
most destructive earthquakes of recent times have 
taken place in the month of February. Among 
others were noted the Lisbon earthquake in Feb. 
1531; that of Aquila in Italy in Feb. 1703; the 
Sicilian earthquakes of 1783; the great earth- 
quake in Central America in Feb. 1797; the Chilian 
earthquake in Feb. 1891; and now to these must 
be added the destructive earthquakes of Zante 
and Samothrace which took place during the 
early part of last month. 
From the statistics that have been compiled it 
has been demonstrated that upwards of 60 per 
cent of the earthquakes that have been recorded, 
have occurred during the six colder months of 
the year. 
The maximum number in January and the 
minimum number in July. 
Such are the results of the calculations for the 
whole area of the globe. But the calculations that 
have been made for separate earthquake districts 
are in full accord with them, and in some cases 
show even a greater proportion for the cold 
than for the warm season. In the Mediterranean 
area this is especially the case as there the number 
of shocks that have been experienced during Dec. 
January and February are to the number felt 
during June July and August as 5. is to 2. 
It is with the greatest pleasure that we are able 
to announce the appointment of our valued col- 
laborator Dr. Johnston Lavis to the professorial 
chair of vulcanology in the University of Naples. 
A magnificent specimen of the shark. Lanina 
cornubica or Smeriglio, measuring 14 feet 9 inches 
was caught by some Gozo fisherman off Cape 
Dimitri on the 12th of February last. 
This species seems to be very abundant this 
year, many have been caught both in the tunny 
nets and with the line. 
The Relationships of the Structure of 
Rocks to the conditions of their 
Formation. 
BY 
Professor H.J. Johnston Lavis m.d.,b.s.,fgs.,etc. 
Again, we find pyroxene, antagonistic to olivine, 
amphibole, and biotite, competing for the magnesia. 
Again, in the Vesuvian pumices, amphibole and 
mica prevail, as these had probably formed under 
great pressure, whilst in the same pumices that 
escaped more slowly, and in the lavas, it is the 
pyroxene that monopolized the magnesia. We 
know that olivine (?), amphibole, and biotite are 
met with in their greatest perfection in plutonic 
rocks, whilst pyroxene is remarkably characteristic 
of rocks slowly cooled near the surface, and under 
low pressure. The fact of the former of these 
having resisted all attempts at artificial production 
points to conditions which have not yet been 
adopted in the laboratory, whilst leucite and 
augite are produced with ease and certainty. We 
therefore must conclude that antagonism of mine- 
ral species in crystallizing from a medium depends 
not only on the composition of that medium, but 
also of the surrounding physical conditions. Prof. 
Haughton (1) admits that, according to his theory, 
olivine - ought to prevail, as it has only to contest 
for iron and magnesia, whilst pyroxene, amphibole 
and biotite, are weakened in the additional fight 
(1) Op. c it. 
