372 Reéramination of American Minerals. 
stance is that recommended by Rammelsberg, the separation of 
the chlorid of lithia from the chlorids of potash and soda, by a 
mixture of alcohol and ether. 
These analyses gave 
J 2 3 
Silica, : n 64:04 63°65 63°90 
Alumina, . F 27°84 } = : 
Peroxyd of iron, . 0-64 { : lie sshd 
Lime, . F 0°84 are 0°31 ; 0:26 
Magnesia, tr. 
Lithia, 5:20 5:05 4:99 
da, 0°66 
Potassa, : 0-16 t 4 oe ; ies 
Ignition, . ‘ 0°50 ‘ 0°50 ‘ 0°60 
~ 99°38 99°30 99-25 
From these is deduced the oxygen ratio for the protoxyds, per- 
oxyds, and silica, 1: 4: 10 and the formula Re Si2+441 Si2, cor- 
responding with the results recently obained. by Rammelsberg,* 
for the composition of the spodumene from Uton and the Tyrol. 
The silica, however, is somewhat lower than that of the Euro- 
pean specimens, which is probably owing to the greater purity of 
the American mineral, it being found in crystals. 
Since completing the above examination of the spodumene 
from Norwich, we have noticed a recent examination of the 
variety from Sterling, Mass., by Rammelsberg in which he states 
uis having found 4°5 pr. ct. of potash, and a ratio nearer 1: 5: 12, 
than 1:4:10. This difference is accounted for by that author 
on the ground that the mineral is somewhat decomposed, and 
that the original ratio was 1:4:10. The fact is, Rammelsberg 
as in many places on the surface, were scales of mica with yellow 
flakes of oxyd of iron ; the specific gravity was 3-073. Now the 
spodumene :— 
; * Pogg. Ann., lxxxy, 544. 
