: This titaniferous iron corresponds in composition to the Wash- : 
“ingtonite of Prof. Shepard as analyzed by M. Marignac, and 
66 J. Lawrence Smith on Emery. : 
first taken to see that it was anhydrous, one gramme of it was 
calcined in a current of oxygen and it augmented -O19, which 
indicated the presence of +171 gramme of protoxyd of iron, and 
corresponds to ‘190 gramme of peroxyd of iron; the same por- 
tion then decomposed by a current of hydrogen gas and the loss 
sustained was equal to ‘222 gramme of oxygen, which corres- 
ponds to ‘740 gramme of peroxyd of iron; deducting from this 
the quantity of peroxyd equal to the protoxyd (-171) contained 
in the mineral, we have -550 gramme for the quantity of per- 
c 
: 
oxyd present. The mass reduced by hydrogen was treated with : 
: 
0 
i 
hydrochloric acid, and the part not dissolved (-230 gramme) was 
titanic acid with a little alumina. The acid solution contained 
010 lime, and a trace of alumina. The titanic acid was exam- | 
ined as to its purity and was found to ¢ontain no silica, and only 
a trace of alumina. The result of the analysis is, 
Protoxyd of iron, 2 : : 17:10 
Peroxyd of iron, . : : . 55-00 BS 
Titanic acid, : : : ; 23-01 L- 
Lime 
Sante ; A 1 
Alumina, ‘ ‘ . alittle, not estimated. 
to 
the titaniferous iron of Arendal analyzed by M. Mosander. Its 
Sp. grav. is 4°78. 
There are still two or three minerals that I have found associa- 
ted with emery, but their specific characters have not been well 
established, on account of the difficulty of obtaining enough in 
a state of sufficient purity for analysis. x 
The study of these accidental minerals in contact with emery 
has led to several general conclusions which have been mentioned 
under the description of the different species ; and now I do not 
risk much in saying, that the hydrates of alumina, as diaspore,—as 
well as the silicates, as emerylite, chloritoid and tourmaline,—an 
the minerals of iron, as magnetic, titaniferous iron, &c,—will 
be found almost everywhere with the emery and corundum. —__ 
My labors on this subject are thus terminated, and it is to be 
hoped that the examination of the emery of Asia Minor has 
served to elucidate the geology and mineralogy of this substance, 
. a * . - o 
_ until now but little known except in its uses. 
