1822.] Composition of the Alkaline Sulphurets. 347 
KS? + Pi; but that which clearly proves that this compound 
was formed after that of K §*, is that in the contrary case, the 
two atoms in excess of K S®°, could not to expel the carbonic 
acid from the potash ; they would have no action upon it, 
exactly as if K S° only was formed, and besides one-third of 
K S* could not combine with the platina, at the end of the opera- 
tion, without being accompanied by some change in the weight. 
It is seen by this how difticult it 1s to obtain K S*, at least by 
this method, because in glass vessels the silica of the glass 
opposes its formation, and in metallic vessels, the sulphur is 
divided between the metal and the potassium, forming a double 
sulphuret. 
These experiments also show the action exerted by the alkaline 
sulphurets in fusion upon the metals: the metal, provided it be in 
sufficient quantity, divides the sulphur with the potassium, until 
KS? is formed. In these double sulphurets, the number of the 
atoms of the metallic sulphuret produced is determined by the 
number of atoms of sulphur in the sulphuret of potassium. 
Experience has shown that many of these double sulphurets are 
decomposed by water, which separate some sulphurets such as 
those of lead, silver, and copper; while others are dissolved, as 
the sulphurets of arsenic, tungsten, tin, and gold. We shall 
hereafter refer to these interesting compounds. 
We have then acquired a knowledge of several sulphurets of 
potassium, which contain 2, 4, 6, 7, 8, 9, and 10 atoms of 
sulphur. 
1. K S®, obtamed by reducing sulphate of potassium by 
hydrogen. 
2. KK S*, by fusing carbonate of potash in a red heat, with a 
quantity of sulphur less than required to decompose it. 
3. K S®°, by heating the above mixture slowly, until it fuses, 
and without ebullition or evolution of any gas. 
4, KS’, by reducing sulphate of potash with sulphuretted 
hydrogen gas. 
5. KS®, by keeping the hepar at a maximum in fusion in sul- 
phuretted hydrogen gas, until neither water nor gas are disen- 
gaged, or by reducing sulphate of potash with sulphuret of 
carbon. 
6. K S°, by fusing the preceding with sulphur, the excess of 
which is driven off by a moderate heat, a current of sulphuretted 
hydrogen gas, or any other gas which contains no oxygen, being 
passed over the liquefied mass. 
7. KS'°, by the fusion of carbonate of potash with an excess 
of sulphur, till no carbonic acid gasis evolved. It is not requi- 
site to raise the temperature above a red heat, to decompose the 
salt completely. 
The combinations in which the sum of the atoms of sulphur is 
expressed by even numbers, answer to 1, 2, 3, 4, and 5 atoms of 
sulphur for each atom of potassium, potash being considered as 
