8 M. Berzelius tvpon the Alkaline Sulphufets, 
combines with a portion of the potash. The potassium (or the 
hydrogen) reduced unites with the sulphur, abandoned by the 
oxidated part of the metal, and the sulphuret of potassium tKus 
produced, combines with the undecomposed metallic sulphuret. 
When an acid is poured into it, the potassium is reoxidated at 
the expence of the metallic oxide, to which it restores the sul- 
phur, and the metallic sulphuret is wholly precipitated as if it 
had been dissolved without decomposition. The fourth method 
gives the same result as the third, with this difference only, that 
the metal is commonly brought to a higher degree of oxidation, 
from which there arise some slight modifications of the pheno- 
mena. We may also add to these a fifth method, that is, when 
a metallic sulphuret is dissolved in a solution of carbonate of 
potash, or of soda. The carbonates, however, dissolve only a 
little of the metallic sulphurets, they are not decomposed, and 
the solution appears to be made like that of a salt in water. Of 
all these metallic sulphurets, that of antimony presents the most 
important results, both from the apparent exception which they 
make to rules, and from the use which has so long been made 
of the preparations of this sulphuret. Water separates the 
greatest part of the sulphuret of antimony from its combination 
with the sulphuret of potassium, exactly as it does the same 
from combinations of the oxide of antimony with acids. Warm 
water, however, separates less of it than cold water. The 
mes mineral is nothing else than sulphuret of antimony sepa^ 
rated in the humid way from the sulphuret of potassium, either 
by the cooling of the liquid, or by the addition of water to a 
concentrated solution. The sulphur auratum of druggists is a 
sulphuret of antimony proportional to the antimonious acid. 
The production of this sulphuret, as well as of the sulphuretted 
hydrogen gas, when we pour an acid into the liquid from which 
the Kermes has been precipitated, arises from a great complica- 
tion in the action of the potash upon the sulphuret of antimony 
It forms two combinations, one of oxide of antimony and pot 
ash, and the other of oxide of antimony and sulphuret of anti- 
mony, ( Crocus antimoni%) which remain undissolved when 
water is added. The warm liquid oxidates quickly at the ex- 
pence of the air, and the sulphuret of potassium, deprived al- 
l”^ady by the water of a part of its sulphuret of antimony, is de- 
