1822.] Composition of the Alkaline Sulphurets. 351 
phur in a solution of potash contained in a vessel ippnided with 
a valve which suffered vapours to escape, but suffered nothing 
to enter. When the sulphur ceased to dissolve in the boiling 
liquid, it was suffered to cool. A portion of it was decomposed 
by hydrate of copper; the liquid, when filtered, was treated 
with aqua regia, and poured into a well-stopped flask. It 
became turbid and milky ; after some hours, it was boiled in 
the unstopped flask ; a small portion of sulphur weighing 0-046 
gramme was deposited. The solution was mixed with muriate 
of barytes, which precipitate 0°95 gramme of sulphate of barytes. 
The filtered solution was precipitated with excess of sulphuric 
acid; then again filtered and evaporated to dryness; after this, 
it was dried with the requisite care, so that there remained 
merely neutral sulphate of potash ; it weighed 1-287 gramme. 
I repeated this experiment with nearly similar results; that is 
to say, the sulphate of barytes weighed one per cent. more than 
the sulphate of potash. This circumstance can only be explained 
by supposing that the saturated hepar contained K S® + 
3 K H* S$", and that in this case, as well as in the dry way, one- 
fourth of the potash combines with hyposulphurous acid, in such 
proportion that the acid contains three times as much oxygen as 
the base. It follows that we ought to obtain by analysis three 
atoms of sulphate of barytes for four atoms of sulphate of pot- 
ash, the weights of which are to each other as 874-8 : 872-8. 
Consequently hyposulphurous acid may combine with bases in 
three proportions: first, that which occurs when zinc or iron is 
dissolved in sulphurous acid, in which the base and the acid 
contain an equal quantity of oxygen; secondly, that which is 
formed when sulphur dissolves in sulphurous salts, or when 
hepar oxidizes in the air; in this the acid contains twice as 
much oxygen as the base; thirdly and lastly, the case which has 
just been mentioned, in which the acid contains three times as 
much oxygen as the base. It is clear that if hydrate of potash 
be added to saturated hepar, a hyposulphate less saturated with 
acid is formed, while the hepar itself suffers no alteration, 
because the relation of the hydrogen undergoes no change. 
This circumstance may occasion the question, if with less sul- 
phur there would be formed, for example, KS? +. KH S?, or 
K 84+ + K H® S'; this, however, does not appear to happen, 
for the smallest quantity of sulphur colours the potash, and these 
combinations would be colourless; or there might be formed 
KS*+ +246 H* Stor K S* + K H* §%, and so on with an 
increasing number of atoms of sulphur up to 10. Indeed it is 
necessary only to add a portion of potash corresponding to the 
weight of + K cr half an atom of. potassium to the saturated 
hepar already mentioned, to obtain the stated relation between 
the quantity of base which combines with the acid, and that 
