METALLIC COMPOUNDS. 
41 
dissolved when shaken in the solution. This salt is flooculent, 
light, and does not adhere to the sides of the vessel. It is not 
decomposed by carbonic acid in the air $ but the nitric acid 
extracts by digestion, though not without difficulty, all the 
barytes it contains. 
Stibias ktilicus is produced by a process similar to the fore* Stibias kali- 
going. It is a white powder sparingly soluble in water j cus * 
for the precipitate produced at the commencement is readily 
dissolved by shaking the solution. Yet it requires but a small 
quantity to saturate the water, and the precipitate, after a time, 
assumes a crystalline aspect precisely like the carbonate of 
lime, and a quantity of these infinitely small crystals is depo- 
sited on the glass, which becomes covered with them. It is 
found, however, that it is not carbonate of lime by decanting 
the fluid, and treating it with nitric acid, which dissolves the 
lime without effervescence, and leaves the stibic acid on the 
glass in the form of a milk white stratum. 
Stibias plumbicus is produced by precipitating nitrate of Stibiate ok 
lead by stibiate of potash. A. white precipitate is formed, ieado 
resembling very much at first the muriate of silver, and which 
is perfectly insoluble in water. When exposed to the Are it 
gives out its water of crystallization, and becomes yellow. 
It does not melt by a red heat, but on a piece of charcoal be- 
fore the inner flame of the blow-pipe it is rapidly reduced 
with a slight deflagration, affording a white metallic button of 
stibiteum plumbi. I was in hopes, by the analysis of this 
combination, of gaining a more exact knowledge of the com- 
position of the stibiates, as it was very easy to obtain the 
stibiate of lead in a neutral state. But I found, to my great 
surprise, that the stibiate of lead, ignited by heat, was scarcely 
at all attracted by the nitric acid, and that the newly-precipi- 
tated stibiate still humid, if poured into concentrated nitric acid, 
cannot be decomposed but to a certain degree, which seems to 
produce the superstibias plumbicus. I endeavoured to decom- 
pose this by several days exposure to concentrated nitric acid, 
nearly boiling, without its being altered. I lastly mixed it 
with charcoal, and reduced it in a glass retort, and afterwards 
treated the reduced metal with nitric acid. The result was 
nitrate of lead and superstibias plumbi again 5 and I could 
net. 
