6 M. Berzelius upon the Alkaline Sulphurets^ and on 
The nature of the solutions of the sulphurets may be explain- 
ed in two ways. They either form hydro-sulphurets of oxidat- 
ed bases, or, as has already been said, the sulphurets may dis- 
solve without alteration. This question cannot yet be resolved; 
and the phenomena are equally explicable upon both hypotheses. 
But in the case of the sulphurets oxidating when they dissolve, 
it follows, that hydrogen ought to form with sulphur as many 
acid combinations as there are degrees of sulphuration of potas- 
sium soluble in water ; that is, we ought to have at least five 
hydro-sulphuric acids, whose combinations with salifiable bases it 
would be difficult to distinguish by any nomenclature at once scien- 
tific and harmonious. It is true, that these sulphurets of hydro- 
gen cannot be all obtained in an insulated state ; but this proves 
nothing either one way or another. For M. Berzelius observes, 
that the hypo-sulphurous acid cannot be obtained in an insulat- 
ed state ; and yet the hypo-sulphites are not less real ; on the 
other hand, sulphuretted hydrocyanic acid exists in an insulated 
state, though it decomposes in contact with potash. 
The sulphuret of potassium has a very great tendency to form 
double sulphurets with a number of substances, particularly 
electro-negative ones. It is owing to this tendency that the 
alkaline sulphurets exercise such a dissolving power over a great 
number of metallic substances; for from KS* to the 
metals appropriate at a high temperature the excess of sulphur, 
and reduce the different sulphurets of potassium to the state of 
proto-sulphuret. 
The proto-sulphui’et of potassium combines with the sulphu- 
ret of hydrogen in the proportion of one atom of the /former to 
two of the latter KS^ -f 2 S. This double sulphuret is 
obtained by passing a current of sulphuretted hydrogen gas 
over the carbonate of potash, at a cherry-red heat, till the gas 
which issues from the apparatus contains water and carbonic 
acid gas. It is slightly yellow, and very crystalline, having the 
appearance of a melted salt. Dissolved in water, it forms what 
is called the neutral hydrosulphate of potash, (considering the 
solution of the protosulphuret of potassium as a sub-hydro- 
sulphate). Sulphur, as well as all the metallic sulphurets, solu- 
ble in caustic potash, drive away from it the sulphuretted hy- 
drogen, and combine with the sulphuret of potassium. Three 
