Feb. 10, 1870] 
NATURE 
383 
orientation is at all known, is examined by it, fails, except in rare 
cases, to be a certain guide to even the system to which such minute 
crystals belong. It was found that the only satisfactory way of deal- 
ing with the problem, was by employing the microscope chiefly as 
a means of selecting and assorting out of the bruised débris of a 
part of the meteorite, the various minerals that compose it and 
then investigating each separately by means of the goniometer 
and by analysis—finally recurring to the microscopic sections 
to identify and recognise the minerals so investigated. The 
present memoir is concerned with the former part of this inquiry. 
Obviously the amount of each mineral that can be so obtained 
is necessarily small, as only very small amounts of a meteorite 
can be spared for the purpose. On this account one has to 
operate with the greatest caution in performing the analysis of 
such minerals and the desirableness of determining the silica 
with more precision than usually is the case in operations on such 
minute quantities of a silicate, suggested the process which, 
after several experiments in perfecting it, assumed the following 
form. After the separation, by alternate treatment with hydrogen 
chloride and potash, of all silicate that gelatinises with acid, 
the pounded and weighed mineral was placed in a small retort 
of platinum with a little ball of the same metal and digested 
with an excess of pure hydrogen fluoride, containing some 32 
per cent. of absolute acid, for two hours, at 100° C. By little 
platinum delivery tubes with which the retort was provided, a 
current of hydrogen was allowed to traverse the apparatus and 
afterwards to bubble through some concentrated aqueous solution 
of ammonia. After the lapse of the two hours the retort was 
placed in a bath of paraffin and its temperature slowly raised till 
132° C. was reached, at which point the silicium difluoride is 
evolved and is carried by the current of gas into the ammonia. 
Ina few minutes the operation is complete and it must be repeated 
with fresh charges of acid and ammonia, till all silicium has been 
driven into the receiver. This done, a little hydrogen sulphate is in- 
troducedinto the retort and the retort once again heated in paraffin. 
If 0:2 gramme of silicate be taken, twice charging of the retort 
with hydrogen fluoride will suffice ; if half a gramme, the process 
may have to be repeated three or four times. The greater portion 
of silicium is removed by the first operation and the ammonia 
becomes semi-solid with deposited gelatinous silica. This 
is slowly evaporated together with the later ammoniacal charges 
and the washings of delivery tube and receiver in a platinum 
dish, and, as the excess of ammonia passes off, a point is reached 
where the last flock of suspended silica is taken up by the hot 
‘solution ; the dish is now removed from the water-bath and to 
its contents, when cold, are added a slight excess of potassium 
chloride and the requisite volume of absolute alcohol. After 
24 hours have elapsed, the precipitated potassium hydro-fluo- 
silicate is filtered off and weighed in the usual manner. The 
metallic oxides present in the mineral, remain in the retort as 
sulphates. 
The Busti Meteorite—This meteorite fell on the 2nd of 
December, 1852, about six miles south of Busti, a station 
half-way between Goruckpoor and Fyzabad, in India. The 
fall was attended by an explosion louder than a thunder-clap 
and lasting from three to five minutes. The explosion 
that shattered the metegrite, must have occurred soon after its 
passing the longitude of Goruckpoor. There was no cloud 
in the sky at the time. The stone, which weighed about 
3lb., was presented to the collection at the British Museum by 
the Secretary of State for India. The Busti aérolite bears a 
great resemblance to the stone that fell on the 25th of March, 
1843, at Bishopsville, South Carolina, U.S. 
The meteorite consists for the most part of the mineral 
enstatite; at one end, however, were embedded a number of 
small chesnut-brown spherules, in which again one detected 
minute octahedral crystals, having the lustre and colour of gold. 
hese two minerals seem scarcely to have been affected by the 
heat that fused the silicates which surround and encrust them. 
The brown spherules are sulphide of calcium (named by the 
author Oldhamite) and they also occur sparsely in the Bishops- 
ville aérolite. This mineral forms small, nearly round spherules, 
whose outer surface is generally coated with calcium sulphate. 
It cleaves with equal facility in three directions, which give 
normal angles averaging 89° 57’ and are no doubt really go”. 
Its system, therefore, is cubic ; indeed, in polarised light it is 
seen to be devoid of double refraction. Its specific gravity is 
2°58 and its hardness 3°5 to 4. With boiling water it yields 
calcium polysulphides and in acids it easily dissolves with 
evolution of hydrogen sulphide. Chemical analysis indicated 
the following as the composition of the spherules :— 
I. II. 
5 Calcium monosulphide . . 89°369 90°244 
eiaiemute Magnesium monosulphide . 3°246 3°264. 
Gypsum. cw teas Galion ft. Sean 4189 
Galciumicarbonates 3,9 <1) 9-8 cy alone esta Sd: —— 
AM 6S. Is a Sh oe —— 2°303 
100'000 100'000 
The presence of such a sulphide in a meteorite, shows that the 
conditions under which the ingredients of the rock took their 
present form, are unlike those met with in our globe. Waterand 
oxygen must have alike been absent. The existence of iron 
in a state of minute division, as often found in meteorites, leads 
to asimilar conclusion. But, if we bear in mind the conditions 
necessary for the formation of pure calcium sulphide, the evidence 
imported into this inquiry by the Busti aérolite seems further to 
point to the presence of a reducing agent during the formation of 
its constituent minerals; whilst the crystalline structure of the Old- 
hamite and of the Osbornite next described must certainly have been 
the result of fusion at an enormous temperature. The detection of 
hydrogen in meteoric iron by Professor Graham tends to confirm 
the probability of the presence of such a reducing agent. Osborn- 
ite is the name given by the author to the golden-yellow micro- 
scopic octahedra imbedded in the Oldhamite, in honour of Mr. 
Osborne and in commemoration of the important service that 
gentleman rendered to science in preserving and transmitting to 
London, in its entirety, the stone which his zeal saved at the time 
of its fall. These minute octahedra gave the angles of the 
regular octahedron ; but the amount, about 0°002 gramme, was 
too small for anything but qualitative experiments. These 
showed the little metallic-looking crystals to contain calcium, 
sulphur and a metal which gives the reactions of titanium in 
some singularly stable state of combination. ‘The next mineral 
described was an augite, of which the measurements and analyses 
were given in detail. Its formula was (¢ Mg, Ca) SiO3. The 
greater part of the meteorite, however, consisted of enstatite, 
which presents itself in three apparently different characters : 
in each, however, the mineral is nearly pure magnesium mono- 
silicate. Of this mineral, the measurements and analyses were 
recorded. The iron contained in small amount in this remarkable 
meteorite, gave as the result of its analysis 79'069 per cent. iron, 
3205 nickel, and r-oo per cent. schreibersite. 
The Manegaum Meteorite of 1843 was next described and 
was shown to consist almost entirely of an enstatite, with 
the formula (2? Mg, + Fe) Si O, associated with small 
quantities of Chromite and of meteoric iron. In publishing 
the results obtained in the attempt, so far as this memoir 
goes, to treat exhaustively of the mineralogy of two im- 
portant meteorites, the author wished to record his obligations to 
Dr. Flight, assistant in his department at the British Museum, 
for his valuable aid in the chemical portion of the inquiry. 
In March, last year, Prof. Maskelyne recorded in a preliminary 
note, read before the Society, his discovery in the Meteorite of 
Breitenbach, of silica in the rhombic systene with the specific 
gravity of fused quartz. It was associated with enstatite with 
the formula ($ Mg, } Fe) SiO . It is singular that the measure- 
ments of the crystals of this enstatite, made at the British 
Museum and published by Prof. Viktor von Lang (Sitzungsh. 
Akad. Wien, vol. lix., 1869, p. 848), accord closely with those 
recently published by Von Rath as the crystallographic constants 
of a kind of enstatite to which he has given the name Ambly- 
stegite. 
LE TEERS LO) PRs DLO ke 
[The Editor does not hold himself responsible for opinions expressed 
by his Correspondents. No notice is taken of anorymious 
communications. | y 
Japanese Sea Shells 
SrncE writing the notice of Dr. Lischke’s work which 
appeared in No. 13 of Nature, I have received from Dr. Lea 
of Philadelphia a typical specimen of his genus Hiffagus and 
the volume of his ‘* Contributions to Geology.” Jor such 2 
valuable communication I would publicly acknowledge my 
obligation to that veteran conchologist. Iwas misled by Philippi 
and Searles Wood, in considering //i*fagus and Terticordia the 
