238 Transactions of the Geological Society of France. 
AEROLITES. 
A mass of iron, partly scoriaceous, found in the environs of Mag- 
debourg, has attracted for many years, the attention of chemists. 
Some have regarded it as an artificial product, inasmuch as analysis 
indicated its composition to be different from that of any meteoric 
iron hitherto examined. M.Srromeyer, who first referred this 
mass to this class of bodies, has repeated the analysis, and presented 
various objections against the idea of its artificial origin. He has de- 
tected in it a very small quantity of nickel and of cobalt, of molyb- 
dena and of arsenic, and a trace of sulphuret of silver: capillary 
native copper and variegated copper ore take the place in it of mag- 
netic iron pyrites. Now the ores of iron and of copper employed 
in northern Germany, have never been known to contain any molyb- 
dena. ‘This fact would seem to prove that the mass could not have 
been the product of the furnace. 
According to M. Burxarr the mass of meteoric iron at Charcas 
near Catorze in Mexico weighs 9 quintals. 
The majority of philosophers have believed, and still think, that 
aerolites and meteoric iron are elevated to a high temperature while 
traversing the atmosphere ; nevertheless there is but little agreement 
concerning the degree of heat observed in them immediately after 
their fall. Recently an experiment of M. Breriey, repeated by 
M. p’Arcer has rendered this high temperature doubtful: a bar of 
iron, heated to whiteness, was held in the current of air, from the 
blowing machine of a forge; the metal did not cool, but burnt bril- 
liantly, throwing off glowing particles in every direction. ‘The tem- 
perature of the iron rather increased than diminished under the in- 
fluence of the current of air. 
M. Jutes Lovis Ipever has discussed with great learning, the 
subject of fire-balls, andof the Aurora borealis, (Ueber d. Ursprung 
d. Feuerkugeln, etc. Berlin, 1832, 8vo.) He is the author also of 
the Meteorologia veterum Grecorum et Romanorum, Berlin, 1832, 
Svo. and of a work on Hail and the electric phenomena of the at- 
mosphere. (Untersuchungen uber den Hagel, etc. Leipzic, 1833, 
8vo.) 
The facts brought forward lead to the following conclusions : 
1. The fall of aerolites generally takes place in summer, and at the 
period of the equinoxes, that is, in the season of the most abundant 
rains. 
2. The frequency of this phenomenon diminishes from the equa- 
tor to the poles, —— in general the annual quantity of rain dimin- 
