VICTORIAN METEORITES, WITH NOTES ON OBSIDIANITES. 
Knowing that a variation is exhibited in the different sections 
of the Beaconsfield, decided enough, in the opinion of Cohen, for 
the sections to have come from two different siderites, it is easy 
to realize how a single section of one siderite might show material 
differences from a section taken from another, although both 
siderites were generally of the same structure and composition. 
In dealing with the chemical aspect Cohen is not satisfied with some 
of Flight’s analyses. He also mentions that a similarity in general 
analyses does not necessarily mean identity of structure in the 
octahedrites, and, conversely, differences in the analyses may not 
point to differences in structure on account of the irregular dis- 
tribution of some of the constituents. As far as he was able to 
express an opinion, Cohen thought it not improbable that the two 
meteorites were of the same fall. Comparing the results of the 
examination of the Cranbourne No. 2 and the Langwarrin with the 
particulars given by Cohen, a great resemblance is noticed between 
the former meteorite and the Cranbourne No. 1, which, as we have 
just seen, is in close agreement with the parts of the Beaconsfield, 
in which cohenite is absent, and in which the structure differs from 
those parts containing abundant cohenite. The fact that the Cran- 
boume No. 2 yielded a section differing from the Langwarrin is 
probably of no importance. The portions taken for ex- 
amination, compared to the sizes of the meteorites, are 
quite insignificant, and had sections been taken from other 
parts of the specimens an identity of structure may have 
been noted, or the structural differences reversed. The 
physical character of the mineral constituents of the Cranbourne 
No. 2 and Langwarrin was quite similar, so that if samples from 
the two were exchanged, the fact could not be detected by examina- 
tion. The relative proportions of the mineral constituents certainly 
vary, but as the irregular distribution of the mineral constituents 
is a common feature, no objection can be taken on this ground to 
the similarity of the meteorites. Neither can the variation in the 
composition of the different constituents be held of any importance. 
Comparatively little work has been done in this direction, and 
apait from the true variation in the composition of a species, the 
elements of error are considerable, and arise, not only from dealing 
with extremely small quantities of material, but from the great 
difficulty of making certain that the material used is pure. 
Geneial analyses are also of little value as they are not made on 
average samples. 
If the chemical composition and physical structure of these four 
meteorites do not materially affect the probability of their having 
originated from one source, then the question arises as to whether 
they represent fragments of one cosmic body which burst on entry 
into the earth s atmosphere, or whether they are independent indi- 
viduals which formed part of a group of meteoric bodies. The 
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