356° hope. 
‘which frét its being insoluble in acids and gritty between 
the teeth, we concluded to be silex. The liquor in which 
this residve was digested, and which was separated by the 
filter, was treated with carbonate of ammonia and a white 
precipitate obtained (No. HI.) which being calcined, weighed 
8.9 grain. This was entirely soluble in a mixture of diluted 
sulphuric acid and sulphate of potash, and crystals of alum 
resulted ; showing it to be alumine. 
D. The precipitate (C. No. I. 9.7 grs.) was observed to 
be but partially soluble in sulphuric acid mixed with sulphate 
of potash; and although alum was formed, yet an insoluble 
residuum always remained. Hence we suspected, either that 
the silex and alumine were not well separated by the fusion 
of the mineral with carbonate of soda, or that the muriatic 
acid as it sometimes does, had taken up some of the silex in 
solution. Circumstances beyond our control prevented our 
treating the mineral, as would have been proper, with borax. 
We therefore digested this precipitate (C. No. I.) repeatedly 
in sulphuric acid mixed with sulphate of potash, to separate 
the alumine and form alum. After several trials of this kind, 
ihe insoluble residue was dried and weighed, and found to 
have lost 6.3 grs. (No. I.) The remainder, 3.4 grs. (No. II.) 
appeared to be silex. This result led us to suspect that the 
siliceous residue (C. No. II.) might contain a small propor- 
tion of alumine. We accordingly subjected it to the same 
process as the precipitate (C. No. I.) just described. Alum 
was formed and there was a loss of 3.33 grs. (No. Hl.) which 
was shown to be alumine. The remainder 11.47 grains, 
(No. 4.) was doubtless silex. 
E. The liquor that remained after the separation of B. Ne. 
3. was tested with an infusion of galls, and gave decided in- 
dications of the presence of iron. No attempt was made to 
ascertain the proportion of this ingredient; and indeed, we 
are not quite sure, but that the muriate of lime used might 
have contained a small quantity of iron. 
F. From the dark stain that appeared on the platina cru- 
cible, in which the mineral was heated with carbonate of 
soda, a suspicion was excited, that lithia might be present. 
We made an aitempt to decompose a smail bit of the mineral 
with pure soda, by means of the common blowpipe, on pla- 
tina foil; and we likewise began the like comparative trials 
with spodumene from Sweden and Massachusetts; a dark 
Stain in most jnstanees appeared upon the foil around the 
