‘The most remarkable feature of the Iowa stone, however, con- 
sists in the homogeneousness | of its earthy composition. It ap- 
rs to contain but a single mineral species of this description, 
and this is one which, though perhaps the most common in other 
oor stones, has until now escaped a separate recognition. 
I have therefore ventured to bestow upon it a distinct name, th 
of howardite, in honor of an individual whose - early scienti 
labors in this seiack of meteorology, rank next in ee to 
those of Chladni himself. 
“he proportions of the igen: in of a appa the 
following : 
. Howardite, » é Peg ‘ » 83:00 
Niekel-iron, ‘ siete See 10:44 
prs 5: 
Magnetic pyri 
Olivinoid and Anortvit, : traces. 
A portion of the stone was ‘seepihiy cleared of the nickel-iron 
by means of the magnet, which however was inadequate to the 
separation of the pyrites. 
“The stone (well cleared of foreign substances) fused easily be- 
fore the blowpipe into a black, scoriaceous glass, which was af: 
tractable by the magnet. 
-'The powdered stone (cleared-of the nickel-iron as above) real 
ily yielded to the action of warm dilute hydrochloric acid ; and 
was quickly brought into solution,,with the separation of floceus 
lent silica. Its analysis gave the following result: 
Silicie acid, eras ? . + OG 
rotoxyd 1 sep ah Pit ‘ » 23°50 
Magnesia, : oe coaster hip 1120 
Magnetic. virion ‘ ae goss OO 
Soda and potassa ‘ , et 0:30 
99-82 
Lime and nickel, KP in traces. 
les. sod the pyrites, the composition of a mineral may be 
stated thus 
sgl Oxygen. Ratio of,oxygen. 
Silicic acid, . ie 4 @3°06 31-53 3 
Protoxyd iron, : iit 3 5-46 1 
lagnesia, . ici ¥ 1 “ a} 
Soda and potassa, : _ dl 
— Itis therefore a tersilicate of protokyl of iron and magnesia 
‘Bedi + Mg Si x io 
The composition of the emt “approaches very closely a 
that of iron 86, nickel 14,—a iar alloy, which I have re 
tofegard as very common in Laie 
