370 C. U. Shepard on Meteoric Iron from Sonora. 
hand, permitted sapeiae 
The fragments were small; the largest piece not weighing 
above one-quarter of an ounce, and that somewhat battered by 
the process employed for its separation. Still, it showed the 
natural outside of the meteor. It was destitute of a well marked 
crust, and much coated with oxyd of iron, evincing in common 
with the other fragments, that this iron is prone to undergo a 
rapid oxydation on exposure to the weather. ; 
ne fresh surfaces presented the color and lustre of white cast- 
iron; though it is not brittle, or granular in its fracture. A close 
examination of a fresh surface, produced by the cold chisel, re- 
veals frequent white spots, of the size of a pin’s head and smaller, 
scattered in every direction, and without any very perceptible 
order. ‘These spots seem to be owing to the presence of an earth 
powder, which adheres closely to the iron, and indeed seems pat- 
tially imbedded therein. When such a surface is highly polished 
on the burnishing wheel, the spots disappear; but are renewe 
again on the application of acids, in the etching process. They 
then come into view, rather more circumscribed in their areas 
than before; but of a very determinate figure, being mostly 
rounded or oval, sometimes with angular indentations in theit 
borders. ‘They are never rhomboidal or rectangular in their out- 
line, after the manner of the much larger earthy grains, or cryS- 
tals, in the Atacama iron, which render the latter porphyritic, 
when cut into slabs. The Tuczon iron on the contrary, when 
thus polished and etched, is amygdaloidal only; and to discern 
this character thoroughly, requires the aid of a microscope. 
_* Proceedings of the American Association for the Advancement of Science, 
Sixth Meeting, p- 188. 
