Meteorites. 
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mixed up with ilie pebbles of other rocks.. It is possible that the lower part of the rubbish 
is much older than the upper, but there is no clearly marked line between them. There 
is, however, no copper near the top, and no bricks, &c,, near the bottom. If the rubbish 
be of one age, the bricks would show that the fissure had been filled in within a com¬ 
paratively recent period, and. it seemed not impossible that the ore was the result of former 
workings washed into the fissure by surface water. I then tried to find any lode; the pebbles 
associated with the copper are so various as to give no clue to its locality if it exist, 
excepting the probability of its being in the Bijawur and not in the crystalline rocks. I 
carefully examined the neighbourhood (or any indications of copper without finding a trace. 
1 also searched the bed of the stream which drains the locality for any loose pebbles, but 
without any result. The only way to prove it really, therefore, seemed to me to sink trial 
pits. 1 discussed the matter with the Assistant Commissioner and gave him what inform¬ 
ation I could on the subject; he expressed his determination to carry on the investigation 
which he had commenced, and it is to he hoped that, his researches will he successful. 
April, 1868. 
Meteobites. —It is well known to those who have studied the structure and character 
of meteorites that, while no single element has been found in these bodies which does not 
occur on our globe, and while a very largo number of the combinations of these elements 
to form mineral species which occur in meteorites occur also on the earth, there still remain 
a few minerals which are specially confined to these bodies. The most important of these 
are Native iron; Schreibersite (or the phosphide of iron and nickel); and Troilite, or what is 
generally supposed to he the protosulphide of iron. Every extension of accurate research 
which tends to diminish this number of minerals special to meteorites is of very high 
interest as bearing on the conclusions to be drawn from their composition regarding the 
origin and physical condition of the planetary bodies. And in this point of view, the recent 
researches of M. Stanislas Meunier, the able adjunct, to Professor A. Daubree, in charge of the 
mitieralogical collection at the Jardin des Plantes, Paris, possess a very wide interest. At 
present we will only allude to his researches on the nature of Troilite, of which we give here 
a summary. M. Meunier has also recently published a very excellent treatise, Etude des¬ 
criptive theorique et experimentale stir les meteobites, 8vo., Paris, 1867. 
On the nature of Troilite, S. Mbusier. “It is known that certain meteorites, 
that of Orgueil, for example, contain small crystals of the second system formed of a 
sulphide of iron, having the composition and characters of magnetic pyrites, or Pyrrhotine. 
This sulphide, ol' which the formula is Ee 7 S 8 , enters into the composition of many terres¬ 
trial rocks also. 
Besides Pyrrhotine, meteorites very often present another mineral of very similar 
composition and which up to the present never has been found crystallized, To this the 
name of Troilite has been given. A certain number of Slineralogists, following 
Mr. Lawrence Smith, attribute to it the formula Pe S, and consequently regard it as constituting 
the protosulphide of iron. This distinction between Troilite and Pyrrhotine is probably 
not so marked as is generally supposed. As seen, the difference in composition is very slight, 
and the physical properties of the two appear very similar. 
I have had lately opportunities of analysing many specimens of Troilit e from the 
meteoric irons of Cbarcas and Toluca, and the numbers which I have obtained lead me 
to think that this mineral is more closely allied to magnetic pyrites, than to the proto¬ 
sulphide of iron. The results of these analyses will be published separately when they have 
been completed and extended to a larger number of specimens, hut I wish at once to call 
attention to a reaction, which seems in all cases easily to distinguish the protosnlphide of iron 
from magnetic pyrites, and, a fortiori, from compounds more highly sulphuretted. 
It seems, at the first view, that this distinction would be very easy, but in reality it 
is not so. The two minerals are of the same bronze yellow colour, their specific gravities 
me very close (T5 for Pyrrhotine, 4'7 for Troilite), and variable within certain limits 
in different specimens: the mean composition differs very little, Pyrrhotine contains (in the 
mean of results) 39'6 of sulphur to 60 4 of iron, and Troilite, in the mean, has 364 of 
sulphur to 63 G of iron ; both are feebly attracted by the magnet; both fuse freely in the 
reducing flame to a black globule, strongly magnetic; both finally dissolve easily in 
Hydrochloric acid, with a very abundant discharge of sulphuretted hydrogen. 
It. is known also that magnetic pyrites is distinguished from the protosnlphide by the 
deposit of sulphur which it gives, when treated with acids, but this reaction, very marked when 
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