VICTORIAN METEORITES, WITH NOTES ON OBSIDl'ANITES. 
acid than the Cranbonrne No. 2 or the Langwarrin, and this fact mav, 
to some extent, support the suggestion that the etched structure 
was, m part, due to the removal of troihte. During etching the 
pitted patches disappeared, leaving cavities with finely jagged boun- 
daries. This may be accounted for by the porous condition of the 
iron in these particular areas permitting a more rapid action of the 
acid than the dense iron, when the intermittent attachment of the 
porous iron to the ground mass would leave jagged boundaries to 
the cavities. These jagged edges seemed to be outlined by a bright- 
white nickel-iron having generally a uniform thickness, and which 
resembled the silver-white taenite-like nickel-iron envelope noted 
in association with some of the troilite nodules in the Cran- 
bourne No. 2 meteorite, only differing in not being quite so 
regular and well defined. The edges assumed a pinkish colour 
after being in a dilute acid solution for some little time, while the 
remainder of the surface of the plate showed an iridescent tarnish. 
Troilite. — On the cut face of the section of the meteorite two 
small patches of troilite occur, one near the centre, in the form of 
a narrow interrupted vein about 1| cm. long by 1 mm. wide, and 
the other of irregular oval form, on the edge of the face. The 
chloride of iron exuded along the margin of the troilite nodule 
occurring on the edge of the section, but the vein in the centre of 
the section only showed a darkening in colour, and no chloride was 
visible. 
The slight scaling observed at many places on the surface of the 
meteorite has no doubt resulted from the decomposition of the 
troihte, both as segregated impregnations and as solid nodules, 
under the influence of the chloride of iron. No minerals were noted 
in association with troilite, it being directly in contact with the 
nickel-iron without the intervention of either graphite or schreiber- 
site. 
Schreibersite. — On complete solution of the nickel-iron a small 
residue remained containing very small bright silvery-white metallic 
particles. These dissolved in aqua regia and the solution gave 
reactions for phosphoric acid, so that the mineral was probably 
schreibersite, but the very restricted amount available was insuffi- 
cient for a qualitative analysis. The mineral evidently occurs 
generally and finely disseminated through the mass, and also, 
perhaps, as occasional small segregations scattered here and 
tb.616 
Lawrencite. — This constituent has been mentioned in connexion 
with its association and influence upon the troilite.. As far as observ a- 
tion went lawrencite did not exude from the solid iron. This fact mat 
be attributed to the more open texture of the patches impregnated 
with troilite and to the comparatively imperfect contact between 
the troilite nodules and the dense ground-mass providing channels 
for the ingress of moisture and subsequent flow oi the chloride m 
1431.— D. I- 49 3 
