Mineralogy and Geology. Q77 
thee 9 Hl. Momaacr AND een 
“ On Petalite and aE Faget by C. Rammetssene, (Ann, der 
Physik und Chemie, Ixxxv, 544, 1852.)—The discrepancies in the 
analyses of these minerals have led M. Rammelsberg to new researches 
with regard to ek composition, and we here give an abstract of his 
paper ig the subjec 
nalyses ae made by means of carbonate of soda and hydro- 
booris ish and with special precautions for accuracy. The following 
are the results. Specific gravity of the Uto mineral, 3°1327; of that 
137. 
of Tyrol, 31 é 
Ut6. Tyrol. 
‘ oe Face ane i" 
; With carb. soda. With hydrofl. acid.  Withcarb, soda. Withhydrof. acid, 
Silica, 65°02 undet. 65°53 
Alumina, 27-70 29:47 80-26 2791 29°97 29-25 
Protox, iron, trace trace trace undet. 140 1-45 
Lime, 0°80 020) ad O84 087. 1-07 
Magnesia, 0-16 trace 5 “"@t 009 0:06 0:06 
Lithia, 550 535 4°49 
_ Soda, 0-51 007 
* Taek = howe Oia 007 
Mean of the results 
Bi 1 fen Gal Mg? Ti: Re EK 
1. Uta, . 65°02 29°14 ¢trace..050 O15 547 046 0:14=100°88 
Oxygen, 83°78 1361 014 006 3800 O11 
*, Tyrol, 6553 2904 142 097 O07 449 007 0-07=10161 
Oxygen, 34-05 1356 0°31 026 003 246 002 O01 
The first ves the oxygen ‘ratio 3:33 : 13°61 : 33-°78=1: 4:0: 10-1. 
The seco ee ad "3-09 : 13°56 : 34-051: 4-4: 11-0. 
Taking. 1:4: 10 as the most posleable ratio, the formula becomes 
Re Sie 441 Se, 
making Spodumene a compound of two bisilicates.* 
_The patbe! of Hagen of the Uté mineral, gave as a mean, 65-022 
of. Silica to 26°837 of ue with 3-836 te lithia, affording the oxy- 
Gen ratio 8:00 : 12-5; :33°79=1: rt AS 11-26, which Hagen makes 
14g: 12, siete found the o 1:4:12. For the Sterling 
(Mass, ) spodumene Hagen cbiktndd, silica 65247, and alumina 27°556. 
M. mmelsberg next cites the analyses of Mr. G. J. Brush from this 
nal (vol. x, p: 870), and alludes to its agreeing with Stromeyer’s 
‘nalysis of the Uts mineral in the silica, in which this last mentioned 
chemist differs from Arfvedson, Regnault and Hagen who found 65 to 
ewe ae . Bere gravity of the Norwich spodumene according 
". Brush, 3: 
65:3 40 earlier —— of the spodamene of Conway, Bowen found 
3 p. ©. of silica and 24:5 of alum 
From all the analyses, A ca ee infers that the formula he has 
Meduced j is the true formula. 
ob Koha ei deduced a similar formula, before soda was Inorg > Ae 
"ND Szates, Vol. XV, No, 44.—March, 1853. 36 
