86 
THE GEOLOGIST. 
fell on it, although at the present time it appears probable that 700 
fall annually?" To which Humboldt has replied, that problematical 
uickeliferous masses of native iron have been found in northern Asia, 
at the gold-washing establishment of Petropawlowsk, eighty miles 
south-east of Kusnezk, imbedded thirty-one feet in the ground ; and 
more recently in the Western Carpathians (the mountain-chain of 
Magura, at Szlaniez), in both of which cases they are remarkably like 
meteoric stones.* 
The Governor of the Island of Reunion (Bourbon), in a despatch of 
the 8th December last, says : — " The volcano of this island is now in 
full eruption. Since last week a torrent of burning lava has been 
seen flowing towards the sea, and all communication with the Arron- 
dissenient du Vent has been cut ofl" ; the lava having crossed the high 
road for an extent of 400 yards, and to the depth of from nine to 
twelve feet." The flow of lava reached the sea on the 9th. This 
volcano of Bourbon is the most active of all those existing in the 
southern hemisphere, between the west coast of New Holland and the 
east coast of America. The greater part of the island, particularly the 
western portion and the interior, is basaltic. Recent veins of basalt, 
with little admixture of olivine, run through the older rock, which 
abounds in olivine ; beds of lignite are also enclosed in the basalt. 
The summit of the volcano of Bourbou, which Hubert describes as 
emitting nearly every year two streams of lava, which frequently 
extend to the sea, is eight thousand feet high. It exhibits several 
cones of eruption, which have received distinct names, and which 
alternately send forth eruptions. Eruptions from the summit ai'e 
not frequent. Tiie lavas contain glassy felspar, and are therefore 
rather trachytic than basaltic. The ashes frequently contain olivine 
in long fine threads, like that produced by the volcano of Owhyhee. 
A violent eruption of these glassy threads, covering the whole island of 
Bourbon, occun-ed in the year 1821. f 
M. Fleurion, professor in one of the Imperial Schools of Agriculture, 
announces to the Paris Academy of Sciences, that, having noted for 
some time past the variations of temperature in the air, and at a 
depth of two metres beneath the surface of the soil, he has found by 
comparing them, that the temperature of the earth at this depth is 
invariably higher by two-tenths than that of the air at the surface. 
It is probable that a slip of the pen has caused the author to write 
down two-tentlis instead of one-tenth. For, taking two metres to be 
(in round numbers) equal to six feet, and admitting an increase of one 
degree Fahr. for every fifty-four feet (English) in depth, we have : 
54 ft. : 6 ft. = 1 " Fahr. : x. 
X = -^^ = 0.111, or 
* Mr. E. W. Binney has described the occurrence of three probably meteoric 
stones in the coal-measures of Lancashire. — Transact. Liter. Philos. Soc. of 
Manrheslcr, vol. IX. — Ed. Geol. 
t For an account of a recent discovery of gold in the island of Bourbon, see 
my article in Tue Geologist for March, 1858.— T. L. P. 
