dissolved in the periodide, and that to its slow decomposition the
feeble conducting power is due. Periodide would be formed, as a secondary
result, at the _anode_; and the mercury at the _cathode_ would also form,
as a secondary result, protiodide. Both these bodies would mingle with the
fluid mass, and thus no final separation appear, notwithstanding the
continued decomposition.

692. When _perchloride of mercury_ was subjected to the voltaic current, it
did not conduct in the solid state, but it did conduct when fluid. I think,
also, that in the latter case it was decomposed; but there are many
interfering circumstances which require examination before a positive
conclusion can be drawn[A].

[A] With regard to perchloride and periodide of mercury, see now 1340,
1341.--_Dec. 1838._

693. When the ordinary protoxide of antimony is subjected to the voltaic
current in a fused state, it also is decomposed, although the effect from
other causes soon ceases (402, 801.). This oxide consists of one
proportional of antimony and one and a half of oxygen, and is therefore an
exception to the general law assumed. But in working with this oxide and
the chloride, I observed facts which lead me to doubt whether the compounds
usually called the protoxide and the protochloride do not often contain
other compounds, consisting of single proportions, which are the true proto
compounds, and which, in the case of the oxide, might give rise to the
decomposition above described.

694. The ordinary sulphuret of antimony its considered as being the
compound with the smallest quantity of sulphur, and analogous in its
proportions to the ordinary protoxide. But I find that if it be fused with
metallic antimony, a new sulphuret is formed, containing much more of the
metal than the former, and separating distinctly, when fused, both from the
pure metal on the one hand, and the ordinary gray sulphuret on the other.
In some rough experiments, the metal thus taken up by the ordinary
sulphuret of antimony was equal to half the proportion of that previously
in the sulphuret, in which case the new sulphuret would consist of _single_
proportionals.

695. When this new sulphuret was dissolved in muriatic acid, although a
little antimony separated, yet it appeared to me that a true protochloride,
consisting of _single_ proportionals, was formed, and from that by
alkalies, &c., a true protoxide, consisting also of _single_ proportionals,
was obtain