1822.] Composition of the Alkaline Sulphurets. 287 
with the disengagement of sulphuretted hydrogen ; muriate of 
barytes poured into the solution did not produce any precipitate. 
- These experiments performed with an alkaline earth and an 
alkali prove then in a decided manner, that the compounds hitherto 
regarded as alkaline or earthy sulphurets are compounds of sul- 
phur with the metallic base of the alkali or earth. 
As hydrogen reduces sulphate of potash, and produces water, 
which evaporates, it is clear that at.a high temperature, sulphur 
may also reduce the potash to sulphuret of potassium, and that 
sulphate of potash ought to be formed at the same time. This 
completely confirms the opinion of M. Vauquelin, with respect 
to what occurs when carbonate of potash is fused with sulphur. 
This celebrated chemist states im his experiments upon the 
compounds of sulphur with the alkalies, that when potash 
unites with sulphur by fusion, a quantity of sulphuric acid ig 
formed, the oxygen of which is equal to that of the potash, 
deducting, however, from the amount, the quantity of oxygen 
which exists in the potash combined with the sulphuric acid ; 
this last portion forms one-fourth of the whole quantity of 
potash ; so that the oxygen of the sulphuric acid can. only con- 
stitute three-fourths of that which exists in the whole of the 
potash. In order to establish this fact, I prepared some hepar 
with one gramme of carbonate of potash, which was fused in a 
small retort with 1+ its weight of sulphur. 
The mixture was dissolved in boiling water, and precipitated 
by muriate of barytes, by which there were obtained in two 
experiments 0°421 gramme of sulphate of barytes. By calcula- 
tion, 100 parts of subcarbonate of potash converted by this me- 
thod into hepar, ought to give 42°15 parts of sulphate of barytes. 
These experiments prove then that when subcarbonate of potash 
nicary with sulphur, one-fourth of the potash goes to form sul- 
phate of potash, and the remaining three-fourths are converted 
into sulphuret of potassium ; this theorem may be employed in 
future in several calculations, and the accuracy of which it was 
proper to prove by experiment, although it was easy to discover 
It @ priori. 
Il. Experiments upon the different Proportions in which Potas- 
sium may be combined with Sulphur and, with Sulphuretted 
Hydrogen. 
Before we proceed to examine the formation of heparin the 
moist way, or by the intervention of water, we shall inquire what 
are the relations in which potassium may combine -with sulphur 
and with sulphuretted hydrogen, which are necessary parts of 
the proposed examination. 
hen sulphate of potash is reduced by hydrogen or by car- 
bon, sulphuret of potassium of the first degree of sulphuration is 
formed ; that is to say, K S*, which is proportional to the sul- 
phate. It is difficult to obtain it pure. If the operation is per- 
