1824.] certain Compounds of Sulphur. 445 



1. The action of a metallic sulphuret. 



2. The action of a metallic oxide and sulphur. 



3. The action of a metallic oxide and a metallic sulphuret. 

 The simplest case is that of putting sulphuret of potassium 



into water. In this case water is decomposed, the oxygen 

 forming potash with potassium, and the hydrogen hydrosulphuric 

 acid with the sulphur; and supposing that an atom of sulphuret 

 of potassium is decomposed, there must of course be formed an 

 atom of hydrosulphate of potash consisting of 



1 atom hydrosulphuric acid (1 + 16) . . = 17 

 1 atom potash (8 + 40) == 48 



~65 



When potash and sulphur are boiled together, the action is of 

 course more complicated. Water must be decomposed, for an 

 acid added to the solution evolves hydrosulphuric acid, and sul- 

 phur is precipitated. Now hydrosulphate of potash is not 

 decomposed by an acid so as to precipitate sulphur, and more- 

 over, although water is decomposed, what becomes of its oxygen ? 

 Does the following take place ? 



1 atom hydrogen = 1 



1 atom sulphur = 16 



Hydrosulphuric acid 17 



And does the atom of oxygen unite with another atom of sulphur 

 to form hyposulphurous acid ? Thus 



1 atom oxygen 8 



1 atom sulphur 16 



Hyposulphurous acid 24 



This appears to be probable, for it will readily be granted that 

 oxygen is not evolved from the decomposition of the water, 

 while its hydrogen is forming hydrosulphuric acid. The oxygen 

 cannot unite with potash, for that is already an oxide, and it 

 cannot convert it into peroxide, for that is decomposed by water. 

 As then in this case both the elements of the water appear 

 necessarily to combine with the sulphur, there are, perhaps, 

 fanned hydrosulphate and hyposulphite of potash. But here 

 again a difficulty occurs : when hydrosulphate and hyposul- 

 phite of potash are treated with an acid, although hydrosulphu- 

 ric acid must be given out by the decomposition of the former 

 salt, neither of them, 1 believe, yields sulphur, which is well 

 known to be precipitated from the solution of sulphur in potash. 

 Is there a third compound formed, which is inrivly a solution of 

 sulphur in potash, and in which no water is decomposed .' Is 

 there in fact formed a real sulphuret of potash ? This appears to 



