be distinct from t 
N. S. Maskelyne on the fall of Butsura. 71 
the siderolites, but, as in the beautiful aerolite of Akbarpir, the 
‘grains of metal seem linked by a ferruginous or iron-stained 
mineral, which may possibly indicate the vestiges of a sponge- 
like structure of the iron at some earlier period in its history,’ 
when perhaps the silicates were less basic than at present, and 
less of the iron oxydized. 
Besides these ingredients, there are several very irregularly- 
_ distributed spherules of a mineral of the greenish-brown color 
and translucency, as well as the lustre, of dirty bees-wax. It is 
somewhat transparent in thin sections, and presents the charac- 
ters of olivine. : 
A minute amount of iron pyrites occurs besides the meteoric 
pyrites; and a little of a very dark-colored mineral is also present, 
generally with a lustrous fracture, and perhaps occasionally 
somewhat crystalline. 
In a section under the microscope with a power of one-inch 
focus, this aerolite does not prove to be a very remarkable one. 
The mass of it seems to consist of olivine. This is associated 
with a gray mineral, and also with one that is of an opake white. 
This gray mineral in some cases seems to constitute entire no- 
dules of the aerolite, and sometimes seems mingled in the sort 
of brecciated mass, containing olivine crystals, that forms other 
nodules in it. It presents the appearance, in the former case, 
either of a dark mottled surface spangled with dark points (con- 
sisting sometimes of iron, and in some cases curiously distributed, 
as if spurted through the mass from a centre), or of a mineral 
presenting very regular and minute parallel cleavage-planes 
with dark gray bars running along them, often rayed out like a 
fan, and with cross-cleavages usually oblique, but at es 
—_ vary with the inclination of the section to the axis of the 
crys 
There is also another mineral, transparent and presenting 
cleavages nearly perpendicular to each other, which appears to 
foregoing. ' He 
hat these minerals thus associated in small proportion with 
the olivine may be—whether they are solely augitic, or whether 
_ iron, to approach in character to a siderolite in that the silicates 
