Editorial Comment. 255 
reach the bottom surface rusted out in that way? The acid- 
ulated waters could not have been retained in them, being 
bottom side up. (5) How could the "pittings" on the bot- 
tom surface be preserved while the waters with which they 
must have been brought into contact were eating such enor- 
mous cavities in the immediate and contacting iron.* (6) 
why are the bottoms of these basins always basin-shaped, 
curving from the sides regularly inward instead of being 
flat and the sides expanded outwardly to the very bottom? 
We prefer to consider all these cavities as due sintply 
to the vacancies left after the removal of other minerals, 
such as troilite, olivine, enstatite and perhaps other silicates. 
It is but fair to Dr. Ward to state that he recognizes this 
possible cause for these cavities. But he plainly does not 
approve it, since he dwells on the causes discussed by him 
at length and only mentions this as a possible alternative. 
Again, the agent of removal of such stony matter he implies 
was heat and friction at the time of the fall, these materials 
being considered by him as "softer and more easily yielding 
to attrition." 
On the other hand these cavities have probably all been 
formed since the meteorite fell, and the manner of removal 
of the minerals that formerly filled them was oxidation and 
solution. The shape of these cavities is characteristic. In 
the association of metallic iron with the usual meteoric sili- 
cates the iron usually presents concave surfaces toward the 
minerals. These concave surfaces come into contact with 
the convex surfaces of the masses of stony matter. The 
iron is cellular or spongy with roundish cavities, and runs 
to points and edges. It appears to have taken shape after 
the other minerals, or in obedience to the crystalline de- 
mands of the other minerals. This is well exemplified by 
the Kiowa meteorite which was illustrated by the writer in 
1890,* and the writer lias observed no exception to that rule. 
* The writer saw, many years ago, a slab of Corniferous limestone 
which had been drawn up from thf bottom of lake Huron by fisher- 
men on their nets in the vicinity of Thunder bay. Michigan, which had 
been corroded by supposed acid waters that entered the lake at invisi- 
ble springs in the bottom of the lake, lis surface was completely cov- 
ered with small basin-shaped depressions about 1*£ inch in depth and 
from 1 to 2 inches in diameter, bui there was no portion of the orig- 
inal surface remaining. 
* American Geologist, May and December, 1890, vols. 6 and 7. 
