344 Zi&. Hunt on some American Minerals. 
This analysis agrees very closely with the results obtained by 
Perez under the direction of Rose, from the samarskite or urano- 
tantalite of the Ilmen mountains; this according to Rose, is iden- 
tical with the yttro-ilmenite of Hermann, which the latter con- | 
ceives to contain a new metallic acid called ilmenic acid, associated 
with titanic acid, yttria, oxyd of iron, and a little uranium. The 
samarskite of North Carolina resembles Hermann’s mineral in con- 
taining oxyd of cerium, which is not indicated in the analyses of 
Perez, but the presence of titanic acid could not be detected, and 
the metallic acid present has been already shown to have the 
characters assigned by Rose to niobic acid. Rose has proved 
that the ilmenic acid of Hermann is the niobic contaminated 
with a little tungstic acid. 
Rutherfordite.—Under this name Prof. C. U. Shepard has de- 
scribed as a new species, a mineral which is found with samars- 
kite, rutile, brookite, zircon and monazite, in the gold washings 
of Rutherford County, North Carolina. A small fragment of 
‘273 grammes weight, given me by Prof. Shepard, has enabled 
me to make a partial examination of the proposed species. It 
as a rounded pebble, iron-black exteriorly, and not at first sight 
distinguishable from the samarskite; it yields to the knife with 
difficulty, and has a hardness probably of 5:5; its specific gravity 
is 5°55 (558-5°69, Shepard.). The fracture is perfectly con- 
choidal, and the lustre vitreo-resinous, shining ; the color of the 
resh surface is blackish-brown; thin fragments however are 
trauslucent, and transmit a smoky orange-brown light. This 
mineral is very brittle, and its streak and powder are of a yellow- 
ish-brown approaching to fawn color, and completely earthy in 
appearance ; by the streak and by its translucency, rutherfordite 
is readily distinguished from samarskite, which it otherwise 
closely resembles, Exposed to heat ina glass tube, it decrepi- 
tates slightly and gives off a little water; the mineral on cooling 
is dark yellowish-brown with a resinous adamantine lustre, in ap- 
pearance resembling some varieties of blende. 
A portion of the pulverized mineral weighing ‘164 grammes, 
which had not been artificially dried, lost by strong ignition over 
a spirit-lamp ‘003 grammes, and assumed a light cinnamon-brown 
color; no glow was observed during the process. It was decom- 
posed by prolonged boiling with concentrated sulphuric acid, and 
was then completely soluble in a large volume of warm water. 
The clear solution became turbid on boiling, and threw down @ 
white precipitate, which adhered in part to the surface of the 
glass vessel, but was completely dissolved by heated strong sul- 
phurie acid even after ignition, and was thrown down again by 
ammonia as a voluminous precipitate which glowed brilliantly 
when ignited. The solution gave with tincture of galls a deep 
. 
