and Union of Supposed Distinct Species. 309 
Oxygen. Ratio. 
Titanic acid, 25.98 4.82 1 
Peroxide of iron, 51.84 10.36 2 
Protoxide of iron, 22.86 5.08 1 
99.98 
The atomic proportions are thus, nearly one atom titanic acid, 
two atoms peroxide of iron, one atom protoxide of iron; or, 
a trititaniate of i iron, consisting of two atoms trititaniated per- 
oxide and one atom trititaniated protoxide. If we unite the 
magnesia and lime with protoxide of iron, in the following 
analysis of an IImenite. from Arendal,’ by Mosander, we obtain 
Precisely the same result. The crystalline form of the two 
Varieties is also the same, and there can be no donbt of their 
identity as one species.’ 
Titanic acid, 24.19 
Boise of iron Nu 53.01 
rotoxide o ifou 
Magnesia and Lime, 1.01 d RBB? 
i referring to the analyses of Ilmenite from other localities, 
it will be seen that the essential constituents, titanic acid and 
the two oxides of iron, so interchange with each as to produce 
different varieties, but all having the same crystalline form. 
= enlin of Breithaupt 
à te rhombohedron, PonP 86° 10^, for the Ilmenite. Shepard, employing 
oia planes of the Washingtonite, makes P on P 86». Prof. Shepard fou fou nds 
Shown to be distinct, i n any essential manner, from the axotomous pae 
S, or from C richtonite (including Ilmenite) : indeed, it nene most pr » 
hos these minerals are not onl y identical in their angles, but are isomorphous 
eM ì iron,” tage vol. xliii. p. 365. The analysis, now, would seem 
‘toy the groundwork Si des piety 
