376 Reéramination of American Minerals. 
This is the same formula as that obtained by Rose, ‘with an 
additional half atom of water, his formula being 
2Fe §2 + 21H. 
Protoxyd of iron was looked for but none found. 
40. Owenite,* identical with Thuringite—with an announcement 
new locality. 
Owenite was first described by Dr. F. A. Genth as a distinct 
species, who gave a minute and accurate analysis in the Am. 
Journ. of Science, vol. xvi, 2d series, p. 167. It was found on 
both sides of the Potomac river near Harper’s Ferry. ‘The phys- 
ical characters being already fully and accurately given, it is need- 
less to repeat them here, merely remarking ‘that its specific gravity 
as taken by me is 3°191. It is readily soluble in hydrochloric 
acid; notwithstanding, analysis No. 2 was made by fusion with 
carbonate of soda. Results of analyses as follows: 

:; 2. Genth. 
; 23 58 23°52 23°21 
Peroxyd of iron, : 14°33 13°89 
Alumina, . ‘ eon eae 16-08 15°59 
Protoxyd of iron, . . 33-20 32°18 3458 
Protoxyd of manganese, . . 009 trace 
Magnesia, . ; : 152 1:68 1:26 
ime, 0°36 
Soda. 0-46 0-41 
Potash, . ‘ ‘ . trace. 0°08 
Water, ; : : 10°45 10°48 10°59 
100°50 99°97 © 
After this examination it was rendered strongly probable that 
Owenite and Thuringite were similar if not identical minerals; 
yet, in the analysis of Thuringite by Rammelsberg, alumina is 
not mentioned as one of its constituents. This view was SUS- 
tained by the apparently perfect accordance in the physical char- 
acters of the two minerals, coupled with the fact that the amount 
of silica and water in the two, as already examined, was the 
same, and also the sum of the oxyds of iron and alumina in the 
Owenite were equal to the sum of the oxyds of iron in the Thu- 
ringite. ‘To settle the question, it became necessary to reéxam- 
ine Thuringite, of which I obtained a specimen from Mr. Mar- 
koe, coming from the original locality ; it was slightly altered by 
the action of the air, but this could interfere only with the cor- 
rect estimate of the protoxyd of iron. Its specific gravity was 
3°186, and its composition, : 
* The identity of these two minerals has already been announced by me in a let- 
thes one of the editors of this Journal (Am. lee, xvii, 131), but no details were 
given. 
