OBSERVATIONS ON ANTIMONY. 
309 
diately, from the solution by the addition of concentrated 
hydrochloric acid, especially when boiling. 
Antimonious acid is more soluble in water than the oxide; 
the filtered boiling liquor becomes cloudy on cooling; it is 
colored yellow by sulphuretted hydrogen, and is deprived of 
its color by ammonia, as entirely as the solution of the oxide. 
When antimonious acid is heated with iodide of potassium 
in a tube, closed at one end, abundant vapors of iodine are 
disengaged, and the residue is an hypo-antimonite of potassa. 
The temperature need not be much increased to produce this 
effect. 
The antimonic acid has also a slight solubility in water, and 
its solution acts with sulphuretted hydrogen and ammonia in 
the same way as the oxide of antimony and antimonious acid. 
The hydrated sulphuret of antimony, which is formed by 
the action of sulphuretted hydrogen on protoxide of antimony 
dissolved in water, exhibits, both while in suspension and so- 
lution, the clear yellow color of sulphuret of arsenic; besides, 
like the former, it is soluble in ammonia; whether this be 
added to the clear and transparent liquor, or to the sulphuret 
itself when deposited as orange yellow floculi. 
I am satisfied that the sulphuret of antimony is really dis- 
solved in the ammonia itself, and not in the sulphuret of this 
base, which is produced by its addition to a liquid containing 
more sulphuretted hydrogen than is necessary for the decom- 
position of the oxide of antimony. For when we add to the 
solution of oxide two or three drops of water of sulphuretted 
hydrogen, certainly not sufficient to destroy all the oxide, the 
yellow color will be discharged by ammonia, the same as if 
the liquid had contained an excess of sulphuretted hydrogen. 
Besides, if, after having decomposed the oxide by a slight excess 
of the sulphuretted hydrogen, the solution be then boiled 
for a short time, the orange yellow sulphuret, which is depo- 
sited, is, when separated from supernatant liquid, completely 
soluble in ammonia. 
The sulphuret of antimony, formed by the action of sul- 
phuretted hydrogen on oxide of antimony, possesses, like the 
