which fell in the Environs of Langres. 351 
I subjected ten grammes of the aérolite reduced into fine 
powder to the action of the sulphuric acid diluted with water. 
The decomposition took place without effervescence:—the only 
phenomena observed were a development of heat and a diminu- 
tion of volume in the substance submitted to experiment. 
Nevertheless the whole mass did not disappear: there re- 
mained a grayish substance, which the sulphuric acid even aided 
by heat cannot dissolve: it forms nearly the tenth part of the 
aérolite. 
The sulphuric acid does not acquire any colour in this opera- 
tion: in the state of dilution in which it was employed, it was 
almost as white as water. , 
There are remarkable differences between this aérolite and 
all that have been hitherto examined. 
All the latter, on being dissolved in the sulphuric or weak 
muriatic acid, gave out hydrogen gas partly sulphuretted, and 
generally furnished a solution of a green colour deeper than that 
of iron: the present aérolite exhibited nothing similar. This 
proves that this aérolite contains no iron in the metallic state 
which the magnet had already announced, and that there is no 
nickel in it, which, as we know, makes its solutions green, and is 
itself acted upon by the magnet. 
The solution being effected, the liquor was decanted and 
washed, and the residue evaporated to dryness. At the end of 
the operation a transparent jelly was formed, produced by the 
separation of the silex, which being washed and dried, weighed 
three grammes and one centieme. 
The liquor, which ought to contain magnesia and iron, was 
again evaporated to dryness, and the residue calcined for at least 
half an hour. The matter, which had assumed a red colour, was 
put into water, in order to dissolve the sulphate of magnesia: it 
was filtered in order to collect the red oxide of iron. 
The sulphate of magnesia must be evaporated and calcined 
three times, in order to separate entirely the sulphate of iron. 
The different quantities of oxide of iron obtained in these 
operations having been collected and dried, weighed three 
ramimes and ten centiemes. ‘This oxide was of a very lively 
, « 
red colour. 
The sulphate of magnesia when purified and calcined weighed 
eight grammes seven-tenths, in which there is about three 
grammes two-tenths of magnesia. This salt was then tolerably 
white, very soluble in water, and had the bitter taste which 
belongs to the natural sulphate of magnesia: lastly, it appeared 
tobe pure. Nevertheless, in order to ascertain if it did not con- 
tain nickel or some other metal, I put hydro-sulphuret of pot- 
ash 
