appear to be decomposed under the influence of the electric current: it
was the water which gave way apparently. The fused fluorides were
electrolysed (417.); but having during these actions obtained _fluorine_ in
the separate state, I think it better to refer to a future series of these
Researches, in which I purpose giving a fuller account of the results than
would be consistent with propriety here[A].

[A] I have not obtained fluorine: my expectations, amounting to
conviction, passed away one by one when subjected to rigorous
examination; some very singular results were obtained; and to one of
these I refer at 1340.--_Dec. 1838._

771. _Hydro-cyanic acid_ in solution conducts very badly. The definite
proportion of hydrogen (equal to that from water) was set free at the
_cathode_, whilst at the _anode_ a small quantity of oxygen was evolved and
apparently a solution of cyanogen formed. The action altogether
corresponded with that on a dilute muriatic or hydriodic acid. When the
hydrocyanic acid was made a better conductor by sulphuric acid, the same
results occurred.

_Cyanides._--With a solution of the cyanide of potassium, the result was
precisely the same as with a chloride or iodide. No oxygen was evolved at
the positive electrode, but a brown solution formed there. For the reasons
given when speaking of the chlorides (766.), and because a fused cyanide of
potassium evolves cyanogen at the positive electrode[A], I incline to
believe that the cyanide in solution is _directly_ decomposed.

[A] It is a very remarkable thing to see carbon and nitrogen in this
case determined powerfully towards the positive surface of the voltaic
battery; but it is perfectly in harmony with the theory of
electro-chemical decomposition which I have advanced.

772. _Ferro-cyanic acid_ and the _ferro-cyanides_, as also _sulpho-cyanic
acid_ and the _sulpho-cyanides_, presented results corresponding with those
just described (771.).

773. _Acetic acid._--Glacial acetic acid, when fused (405.), is not
decomposed by, nor does it conduct, electricity. On adding a little water
to it, still there were no signs of action; on adding more water, it acted
slowly and about as pure water would do. Dilute sulphuric acid was added to
it in order to make it a better conductor; then the definite proportion of
hydrogen was evolved at the _cathode_, and a mixture of oxygen in very
deficient quantity, with carbonic acid, and a little car