340 
THE MEDITERRANEAN NATURALIST 
sing from the amorphous to the crystalline con- 
dition. Or again, to their early union with other 
elements of the lava. This may possibly be so, 
the combination being broken up by a lowering of 
temperature (?), leaving the chlorides free to the 
sublimed. It seems tome that the chlorides must 
be continually escaping, but that they are not 
deposited until the scoria and. fumarole sides are 
cooled enough to allow such to occur. The liquids 
included in cavities in crystals are generally solu- 
tions of chlorides or sulphates. 
There is little doubt that these saline materials 
must form a very important constitutent of the 
magma; but whether they play much part as a 
solvent medium for certain minerals is a thing yet 
to be experimentally verified, though one is incli- 
ned to think that they really do perform a very 
important function in that way. One point open 
to speculation is whether the presence of sodic and 
potassic chlorides and sulphates is not the deter- 
mining cause as to whether the magma shall con- 
tain leucite hauynite, nosite, or sodalite. For 
instance, we find Monte Yultura producing at dif- 
ferent epochs basalts, lencitic basalts and hauynite 
basalts, which might result from the accidental 
introduction of such salts from the sea or other 
sources. We might suppose the salts are decom- 
posed and dispersed as acids, whilst the bases 
are seized upon by the silicic acid which, in a 
magma at high temperature, has powerful acid 
properties, and so forms minerals of the leucite or 
felspar groups. 
In these papers I have brought together a con- 
siderable number of observations, and endeavoured 
to glean from them the clue to some of the most 
important problems of geological science. The 
train of argument is somewhat disorderly; but 
from the large number of circumstances that enter 
into the question of the formation of igneous rocks, 
the subject is difficult of arrangement. It. is un- 
mistakably evident that if the young science of 
petrology is intended to be carried beyond the 
simple dry description of rock masses, it must be 
brought to bear upon the various modifications 
and derivatives of them, in any given district, and 
also that it will never supersede field investigation; 
but by the two going hand-in-hand they may 
open the doors and show us the secrets of Nature's 
great chemical laboratory— our globe. 
The Lands of Volcanoes. 
In the Japan and Kurile Islands, according to 
Prof. John Milne, not less than 100 volcanoes 
still preserve their form an I craters, and as ma- 
ny as 50 of them emit steam. The great erup- 
tions which have been recorded number 23S. the 
greater frequency, as with earthquakes, having 
been during the colder months of the year. One 
line of vents, more than 2000 miles long, begins 
in Kamschatka, and passes through the Kuriles, 
Yezo, and down by Honshiu to the eversmoking 
Asama, where it is joined i >y a line running to 
the southwest through the great Fujisan and 
Osharna, till it reaches the Ladrones, a distancee 
of 1200 miles. The last line begins near the gi- 
gantic crater of Mount Aso, and extends 130.) 
miles through Formosa to the Philippines. The 
lavas are all magnetic, and the soil of the coun- 
try, consisting largely of decomposed lava, is in 
many places so tilled with grains of magnetite 
that a brush of this material will be collected 
on a magnetized knife scraped over a garden 
walk. The most famous of the volcanoes is Fu- 
jisan. On its summit, at a height of about 12. 
400 feet, Prof. Milne has made observations with 
a tremor— measure that tend to prove that the 
great mass of the mountain is actually swayed 
by the wind! 
The Geology of Arabia Petrea and 
Palestine 
At a recent meeting of the Geological Society 
of London a paper entitled. “Outline of Geolo- 
gical Features of Arabia Petrea and Palestine. ’ 
by Prof. Edward Hull, f.k.s.. f.g.s. was 
I read, of which the following is an abstract, taken 
from the “Proceedings of the Geological Society 
of London. 
The regions may be considered as physicalv 
divisible into five sections, viz.: — (i) The Moun- 
tainous part of the Sinaitic Peninsu la : (ii) the table 
land of Badiet-ei-i ik and Central Palestine; (iii) 
the Jordan Arabah valley; (iv) the table land oi 
