the Combinations ofAUmlies with Metallic Sulphurets* 3 
supposed, and that it is not this sulphuret of potassium only, 
which renders the pyrophorus of Homberg so extremely com- 
bustible. 
KS^, (M. Berzelius found, that it would be too much to 
make a nomenclature for these different sulphurets,) is obtained 
when sulphur is exposed, with an excess of carbonate of potash, 
to incandescence in vessels closed against the entrance of air. 
3. KS®, When the mixture of sulphur with carbonate of po- 
tash in excess is exposed to a red cherry heat, till it disengages 
carbonic acid, or when carbonate of potash is decomposed by 
fire, by means of a current of the vapours of sulphuret of car- 
bon, 
4. KS’'. When the sulphate of potash is reduced by means of 
sulphuretted hydrogen gas, the sulphur is remarkable for its 
transparency, and by its wine-red colour, bordering a little up- 
on yellow. A part of the sulphur of the sulphuretted hydro- 
gen is set at liberty during the operation, and is deposited with 
the water in the cold part of the apparatus. 
5. KS®, By the reduction of the sulphate of potash by means 
of the vapours of sulphuret of carbon ; or when sulphuretted 
hydrogen gas is passed over the ordinary hejpar^ till the sulphate 
of potash which it contains is decomposed. 
6. KS®, When sulphur is added in excess to the preceding, 
and the mixture is heated in a current of sulphuretted hydrogen 
till it yields no more sulphur. 
7. !KS^°, Is the saturated combination of sulphur which con- 
stitutes the ordinary hepar^ when it is prepared by adding to it 
sulphur in excess. 
With respect to KS”^, KS®, M. Berzelius has doubts of their 
existence, not because the result of the experiment which yields 
them is doubtful, but because these odd numbers are not yet 
known in any other inorganic combinations. They may, besides, 
be very likely nothing more than fixed and determinate combi- 
nations of two other sulphurets of potassium ; for this evidently 
takes place with the sulphuret of magnetic iron, whether native 
or produced artificially. In this last substance the iron is, ac- 
cording to the j^periments of Stromeyer, combined with Ifth, 
as much sulphur as in the true protosulphuret of iron, and, con- 
sequently, is as 7. to 6. 
