A CATALOGUE OF OBSERVATIONS OF LUMINOUS METEORS. 415 
the zodiacal light completely surrounding the ecliptic, termed by German 
astronomers the Gegenschein, of which M. Schiaparelli has himself frequently 
corroborated the appearance at Milan. It will be sufficient to notice, in 
closing the present abstract, that the result of the investigation is not favour- 
able to the assumption that the outer portion of the zodiacal light consists of 
solid bodies, shining by borrowed light which they reflect to us from the sun. 
“Synthesis of Meteorites.” By M. Daubrée (Comptes Rendus, 1866, Jan. 
> 29-March 19, vol. Lxii. pp. 200, 269, 660).—By the help of a high heat*, 
—————ee 
in one of the gas-manufactory furnaces of Vaugirard, supplied with gas-coke, 
M. Daubrée succeeded in liquifying the intractable materials of upwards of 
thirty different aérolitic falls. After solidifying, the fused mass was found 
to consist of a vitrified slag in the case of the three unique meteorites of 
Juvenast, Jonzac, and Stannern, which differ from the ordinary type of 
aérolites in the presence of alumina. The magnesian or common type of 
aérolites, on the other hand, separates on cooling into two distinct and regu- 
larly crystallized minerals, one of which forms a pellicle of square-based, 
octahedral, or occasionally lamellar crystals, and is peridot, or protosilicate 
of magnesia. The meteorite of Chassigny consists entirely of this mineral, 
with a small percentage of chrome-iron ore. The other mineral, of which 
the meteorite of Bishopville is almost entirely~composed, is enstatite, or 
bisilicate of magnesia. It crosses the centre of the mass, apparently on ac- 
count of its greater fusibility, in groups of long square prisms, of very per- 
fect form, and generally in one direction. The crucibles being lined with 
charcoal to preserve the contents from contact with the air, a portion of the 
iron contained as silicate is reduced; and the silica set free, combining with 
a portion of the peridot, thereby increases the quantity of enstatite. The 
ease with which these two minerals crystallize from the liquid state makes 
it probable, as supposed by Mr. Sorby, that the confused mass of very small 
broken and imperfect crystals of which the magnesian aérolites consist must 
have been deposited by sublimation, like flour of sulphur, from a state of 
heated vapour. 
In order to test the affinity of terrestrial rocks with aérolites in this re- 
spect, several magnesian silicates were fused, and those which gave results 
most similar to those of aérolites were found to be,—1°, Peridot from the 
basalts of Langeac (Haute Loire); 2°, Peridotic hypersthene from Labrador ; 
3°, and especially, Lherzolite (a mineral found at many places in the Pyrenees) 
from Prades, consisting of a mixture of the magnesian minerals of peridot, 
enstatite, and pyroxene. The result of fusion of these rocks, in the pre- 
sence of charcoal, is exactly similar to that of aérolites: the two magnesian 
silicates contained in them crystallize separately ; and the reduced iron ex- 
tracted from the mass contains a proportion of nickel, which, as shown by 
Stromeyer, is present, with phosphates (found by G. Rose, and by M. C. St.- 
Claire Deville in Vesuvian lavas), as well as chromite, in most of the basic 
rocks which spring from a source below the granite. A phosphate (apatite) 
was also found by Rammelsberg, together with titanium, in the rare aluminic 
meteorite of Juvenas; but the presence of titanium in meteorites of the com- 
mon or magnesian type was first discovered by M. Daubrée, in the course of 
his experimental fusions of the meteorites of Montréjau and Aumale. 
Several attempts to imitate meteoric iron by fusion were partially suc- 
cessful, as in the liquefaction and reduction of lherzolite and the peridot of 
* The heat of melting platinum was employed throughout the experiments. 
+ In the case of Juvenas, the mass, on solidifying, is porous and full of air-bubbles, as 
if gas were disengaged from the meteorite at a high heat. 
