96 
POPULAR SCIENCE REVIEW. 
the author supposes the silica in hot solution to have come in contact with a 
limestone under pressure, setting free carbon dioxide, which being enclosed 
in the crystal cavities along with water would on cooling condense to a 
liquid. — (“ J. Chem. Soc.,” xxix, 137.) 
Volatility of the Alkaline Earths. — A paper was recently read before the 
Chemical Society by Professor J. W. Mallet on the above subject. The 
author has ascertained by a series of carefully made experiments that 
lime, baryta, or strontia heated in contact with metallic aluminium to a 
very high temperature in a carbon crucible, suffers an appreciable loss of 
weight, in some instances to the extent of more than 3 per cent., indicating 
that the alkaline earth must have been partly reduced and the metal volati- 
lized. This supposition is confirmed by the observation of the flame cf the 
carbon monoxide which is given off, the characteristic lines of the metals 
being distinctly visible when it is examined with the spectroscope. 
GEOLOGY AND PALAEONTOLOGY. 
Submarine Upheaval in Greece. — M. J. de Cigalla writes from Corfu, to the 
French Academy of Sciences, describing a curious upheaval of the sea 
bottom which has occurred in the little bay or port of Karavossera, in the 
Gulf of Arta. In November 1847 and February 1865, after some shocks of 
earthquake, a very dense sulphurous vapour issued from the bottom of the sea; 
this killed great numbers of fishes and other marine animals, and rendered 
the sea milky as far as Previsa. These sulphurous emanations still continue, 
especially when the wind is in the south, but they are not sufficient to 
cause any destruction of animals. Previous to 1847 the spot from which 
the emanations proceeded had a depth of 8 fathoms according to the charts, 
but in the spring of the present year Lieut. Miaulis, of the Greek Navy, 
found that the bottom had risen in the form of a cone, having a circum- 
ference of about 300 fathoms, and with its apex only 2 fathoms 4 feet 
below the surface of the sea. No increase of temperature was perceptible in 
the sea, but objects sunk at this part, and left for a time, are said to become 
encrusted with sulphur. 
Two New British Formations. — There are certain things that demand 
courage, and one of them is the establishment of a new British geological 
formation. Nevertheless, Mr. Hicks has ventured to introduce two new 
divisions among those ancient rocks of the St. David’s promontory, of which 
he ha3 successfully constituted himself the historian. The rocks thus 
honoured form the central ridge of the promontory, and were formerly re- 
garded as consisting of intrusive syenites and felstones ; but, according to 
Mr. Hicks, this ridge is entirely composed of altered sedimentary rocks of 
earlier date than any Cambrian deposits, the conglomerates at the base of 
the latter being chiefly made up of pebbles of these rocks. In the ridge 
Mr. Hicks has recognized two distinct and perfectly unconformable series. 
The older of these, occupying the centre of the ridge, consists of quartzites 
and altered shales and limestones, has a N.W. and S.E. strike, and dips at 
a very high angle ; the newer series, composed of altered shales, and having 
