1868. ] Mineralogy. 419 
sibly be only an altered form of olivine. Its composition is thus 
given :— 
SHEED Sha aa? Wea che Body shat cbs aon ued) 
Alumina sed RAS. 1 cme Sah wescaew ey le carl! 
Thrigte es. MEA ace nese eae ease ote OO 
Wiaeheria Wise s20h ool leech) sade ll 
ETotoxideOlITOngg |i dest Well esas ge LO 
5 OLMBNPRNERO, wen, vcs) 4g cence Leo 
Water heres Seat, PS Pe Pee 
100°36 
Professor Hermann has again directed his attention to the study 
of the rare mineral Colwmbite.* He shows that the metal tantalium 
is present in this mineral in the state of tantalic acid (Ta, O ), and 
may therefore be replaced by the corresponding acids of niobium 
and ilmenium. Hence he establishes for columbite the general 
formula, RO, R, O,, where RO represents the protoxides of iron and 
manganese, whilst R, O, represents tantalic, niobic, and ilmenic 
acids. 
The Swedish mineralogist, Igelstrém, describes a new species 
from the iron mines of Langban, in Wermland.t From the manner 
in which it is disseminated through the matrix, he proposes to call 
it Kataspilite. It may perhaps turn out to be an altered variety of 
cordierite, with which it agrees in crystalline form. Its composition 
will be seen from the following analysis :— 
Silicays tse Ueonase ie eer ee Les mas eee 2000 
Alumina and peroxide ofiron .. .. .. 28°95 
emer att Ruta tee Eee deca icces ike 
ESSN ais Fsiaad sa\veieeilh axe, Oeoy, ata toe EO 
Pina ets Ove i a may ce oa 
BGGAe. toes Yepa oe, tga fetta Mae eee 
gaa pia) Pane wad ict ean: pee Rai, oe te 
100°00 
An elaborate study of the optical characters of the minerals 
Harmotome and Wohlerite has led M. Des Cloiseaux to the con- 
clusion that the crystalline forms of these species must be referred 
to the oblique system, and not to the rhombic system, as previously 
imagined. 
Professor Rammelsberg has been engaged in investigating the 
chemical composition of prehnite, talc, steatite, and chlorite; but his 
researches are not of general interest.§ 
On the 30th January of the present year a remarkable shower of 
meteoric stones fell at Sielce and Gostkow, near Pultusk, in Poland. 
Several of these stones are now in the British Museum. Externally 
* «Journ. f. prakt. Chemie,’ 1868, p. 127. 
+ ‘Neues Jahrb. f. Mineral,’ 1868, Heft 2, p. 203. 
¢ ‘Proc. Roy. Soc.,’ vol. xvi., No. 101, p.319; ‘Phil. Mag.,’ June, 1868, p. 461. 
§ ‘Zeitschr. d. Deutsch. Geol. Gesell.” Bd. xx., p. 79, 82. 
