a Mineral from Faroe. 49 
tion, it weighed 14.35 grains. It dissolved in boiling potash ley 
except a residue of .47 of a grain, which shall be afterwards no- 
ticed. ‘There was thus left of silica 13.88 grains. 
d, The liquid separated from silica was treated with ammo- 
nia in some excess. A few flocks only fell, becoming gradually 
brown. These were separated by filtration, and, after ignition, 
weighed 14 of a grain. 
e, These ignited flocks were digested in muriatic acid, and 
were dissolved, except a residue of .02 of silica. The solution 
was boiled with excess of caustic potash. The precipitate re- 
maining undissolved was separated by filtration, and the liquid 
supersaturated with muriatic acid, and treated with carbonate 
of ammonia. A slight muddiness ensued ; but the quantity or 
nature of the precipitate was not determined, from its small 
amount. 
f, The residue left by the caustic potash in e, was dissolved 
in muriatic acid, boiled with a little nitric acid, neutralized by 
ammonia, and precipitated by benzoate of ammonia. The pre- 
cipitate, ignited with a little nitric acid, yielded .04 of oxide of 
iron. The residual liquid was boiled with carbonate of soda. A 
white precipitate fell, which, after ignition, weighed .05. This, 
when examined, proved to be oxide of manganese, mixed with 
some lime ; but as the proportion of lime could not be determined, 
the whole may be held as red oxide of manganese, equivalent to 
046 of protoxide, although, from the reaction of the mineral on 
platinum foil with soda, formerly mentioned, the real quantity of 
that oxide was apparently less. 
g, The liquid. which had been precipitated by ammonia in d, 
after concentration by heat, was brought nearly to the boiling 
point, and carbonate of ammonia added. A plentiful white pre- 
cipitate fell, which, after being collected by filtration, and duly 
dried, weighed 11.74 grains. This precipitate, which was carbo- 
nate of lime, dissolved without residue in diluted muriatic acid. 
A few drops of hydrosulphuret of ammonia were added to the 
VOL. XIII. PART I. G 
