HBighth Supplement to Dana’s Mineralogy. 371 
nanxuinite [p. 166, I, VII].—The chemical composition of this mineral has 
‘ 7 studied ‘by “e mmelsberg (Pogg. Ann., cvii, 312), and the causes of 
he disagreement in former anatyses po ointed ont, His a analyses, partly 
from massive, and partly from crystallized specimens, gave: 
: : 4, 5. 
#e 64:28 65:32 6492 6840 64°64 
G.=5'21 + Mn 13°08 13°87 13:28 1381 
Zn 25°09 26°83 25°51 
10388 10351 1 
Analyses 4 and 8 were made by Schulz in Rammelsberg’s Laboratory. The mean 
is Pe 64°51, Mn 13-51, Zn 25-30 (excluding Zn in No, 4) =108°52, equal to 
Mn Zn oO 
9°38 20°30 95°16 = 100°00 
Equivalents, yt 1° 18 9°3 
The atomic a between the metals and the oxygen is.7-6 : 9'S==1 : 1:25 :6 
or R506. Rammelsberg proves by hen gong t that at least a portion of the man- 
fanese must be "peices, and after the consideration of spe hypotheses in 
regard to the oxydation of the iron and ee which show the euaparey 4 
of the composition of the mineral ing to the s inel phi i t 
assume the whole of the manganese to e sesquioxyd. He then aictlaten the 
gen Sew after eos that pont with the zinc’and manganese, as be- 
longing to the iron. This giv 
a Oxygen. Bd Oxygen. 
Min «18°51 418 ) 15.61 13°51 1 18) io-56 
. 31-64 9-48 27-50 s 95 
e 29°55 6°55 33°31 38 ' ‘ 
Zn 2530 S500 of 1155 9530 ~— 005 17 88 
100-00 95:16 99°62 24°76 
Column b is a correction of the calculation £0 as to make the oxygen of f the pat 
pe bag sesquioxyds equal, and corresponds to the amount of iron found in 
The oxygen — calculated di : 
"The calculation of the c ct <oe eee R506 in which Mn: Zn: e==1:2:5 gives 
Fe 45:24, Mn 8°92, Zn 21 04, © 24°81, or He 64°66, Mn 12°80, ZnO 26°19=108°65, 
corresponding very well with a rata of the analyses, and giving the formula 
(Fedin)® PeMn) or R*4 Rammelsberg considers th i pee sireaiy 
asa hism of and it, alrea 
shown in 9 prend investigations aaghey Lege i augite, and the different varieties 
of om and titanic iron. [An n atialyate of iy i by the 
nearly w 
G3, 4B.) 
rred to 
AtEa |p. 36, II—IV, V The so-called seinmannit already refe 
plea by Re enngott ( (Veber 1865 855, 109), has recently eco gt by Schwarz 
| Wien. Akad. ‘Ber., xxv, 561), with the follow 
PbS SbS. ZnS ra | 
iwi 76-48 se nee 11°38 9-10 = 99°98 
b ‘one aarp gave 2 p.c. less lead, a trace of zine, an and s searcdly any arsenis, 
: ti 2 7 * . 
pa ‘hued ro lgg shag som roto Pro s “aie draws the conclusion that sul 24 
ee is the only constant constituent, and that steinmannite is an impure galen si 
Schischi 
[p. 190, I~VII].—Analyses of lime-iron-garnet from the 
ae al (0 an iy veils ok (2) pci he grossular from Depart mae River 
tone under the direction of N. v. Iwanow_in the Mining- “ahve 
a St. Petersburg gave pear Mat. Min. Russlands, ill, 
