on = eee. 
Mineralogy. Ixxxi 
ae) »». 79212 
Ls eA ees ae 17-225 
Mathie es dep ce 5's + i00. Se 
102-198 
He considers it as composed of an atom of the sexsilicate of 
 jithina and three atoms of trisilicate of alumina. Hence its 
symbol willbe LS®° + 3AS*%. = 
5. Spodumene, or Triphane.—This mineral had been examined 
by Vauquelin, who had found it to contain 10 per cent. of pot- 
ash. Hisinger and Berzelius analyzed it afterwards without 
detecting any alkaline ingredient whatever. This want of coin- 
cidence induced Arvedson to resume the examination of the 
mineral anew. The result of his experiments gave the consti- 
tuents as follows : 
ah. dts dg anne ».-. 66°40 
Atamina®>‘. 2 ..¢ Heels’ 5o'spheaae 
UIA iaicie canis a cin.» atop eee 
Qeule. of irothii eid cicee 1-45 
Volatile matter ........... 0:45 
102°45 
Vogel’s analysis of the Tyrolese spodumene, if we suppose that 
the alkali which he denominates potash was really lithina, does 
not differ very materially from the result obtained by Aryedson. 
{t is as follows : 
Silica... ‘: < ow tela 8D0 
Alanine. asses ost vues ian 23°50 
Liame@es + xs ccrersbateiewue 2.00 ie : 
Potashyts ds jie <u ti sly fie SE HOD 
Oxide of iron. .......50.0. 2°50 
Waters aceckh tobe avid. 2-00 
Manganese 2.4 sis sss cv Trace 
99°25 
(See Annals of Philosophy, xii. 392.) _ 
6. Green Tourmaline, called Crystallized Lepidolite—This 
mineral resembles the tourmaline, but is much softer; being 
easily scratched by a knife. Though it has been considered as 
a crystallized lepidolite, there can be no doubt, both from the 
shape of its crystals and from the result of the analysis of Ar- 
vedson, that it is merely a variety of tourmaline ; the consti- 
tuents which he found being nearly similar to those found by 
Klaproth and Vauquelin in the rubellite. Arvedson’s analysis 
gave the constituents as follows : 
Vou, XIII, f 
