MINERAL CONSTITUENTS OF METEORITES. 
195 
dispersion of the outer parts of the stone in its career through the air, fused down with 
portions of the silicates into a dark and perhaps more fusible enamel that has mixed 
unevenly as it flowed over the less fluid glass of the silicate. The enamel, it should be 
added, has generally vesicular appearances when seen under a high power, as if gases 
had escaped from it during its fusion. 
One end of the meteorite presented a remarkable feature ; small round chestnut-brown 
spherules, coated with yellowish-white fused silicate, stood out from a well-defined nodule 
that was imbedded in this portion of the stone near N in the upper view. In these small 
spherules there might in one or two places be seen, with a lens, minute octahedral 
crystals with the lustre and colour of gold. These two minerals seemed scarcely to have 
been affected by the heat that fused the silicates in which they are imbedded, and which 
protected their surfaces from the action of the atmospheric oxygen; but in one or two 
cases the crust at these spots was rendered darker in colour by the influence of the 
nodule it covered. 
It was indeed fortunate that this meteorite came in its entirety into the British Mu- 
seum. A blow from a hammer (the too usual fate of Indian meteorites) would have 
scattered the contents of this nodule as dust, for its peculiarities were only visible from 
the outside on very careful inspection. A section was made so as to pass through this 
nodule ; it was then seen to be definitely bounded by a black line, within which two 
distinct silicates could be detected, and the polished surface was dotted with the round 
spherules of the chestnut-brown mineral that has been alluded to. A representation of 
this section parallel to the line N is given in Plate XXIII. 
The powder produced in the cutting of the meteorite and a few fragments of the 
separated portion, too small for distribution to other museums, were retained for chemical 
examination, and slides of the different minerals were worked from some of these frag- 
ments for the microscope. A small nodule of the metallic iron was also preserved for 
analysis. From the fragments the different minerals were picked out under the micro- 
scope, and among these a few specimens were found sufficiently complete to throw light 
on their crystallography. 
IV. Oldhamite — Sulphide of Calcium. 
I gave the name of Oldhamite to this mineral in 1862, when it first attracted my atten- 
tion, though I had not then the opportunity of properly investigating it*. 
Oldhamite is a pale chestnut-brown and, where pure, transparent mineral occurring 
in the Busti aerolite, and apparently also sparsely in that of Bishopville, in small nearly 
round spherules imbedded in enstatite or augite, or in a mixture of both. The outer 
surface of the spherules is generally partly coated by calcium sulphate, the result of the 
* I named it in compliment to Dr. Oldham, Director of the Indian Geological Survey, who in that year acted 
on behalf of the Asiatic Society of Calcutta on the occasion of that Society giving, in the most liberal spirit, 
to the British Museum large portions of several important aerolites that had fallen on Indian territory, and. 
were preserved in its Museum. 
