_Chlorides_ of the metals are instantly decomposed by fluorine,
generally at the ordinary temperature, and in certain cases, antimony
trichloride for instance, with the appearance of flame. Chlorine is in
each case liberated, and a fluoride of the metal formed. A few require
heating, when a similar decomposition occurs, often accompanied by
incandescence, as in case of chromium sesquichloride.
_Bromides_ and _iodides_ are decomposed with even greater energy, and
the liberated bromine and iodine burn in the fluorine with formation
of their respective fluorides.
_Cyanides_ react in a most beautiful manner with fluorine, the
displaced cyanogen burning with a purple flame. Potassium ferrocyanide
in particular affords a very pretty experiment, and reacts in the
cold. Ordinary potassium cyanide requires slightly warming in order to
start the combustion.
Fused _potash_ yields potassium fluoride and ozone. Aqueous potash
does not form potassium hypofluorite when fluorine is bubbled into it,
but only potassium fluoride. _Lime_ becomes most brilliantly
incandescent, owing partly to the excess being raised to a very high
temperature by the heat developed during the decomposition, and partly
to the phosphorescence of the calcium fluoride formed.
_Sulphides_ of the alkalies and alkaline earths are also immediately
rendered incandescent, fluorides of the metal and sulphur being
respectively formed.
_Boron nitride_ behaves in an exceedingly beautiful manner, being
attacked in the cold, and emitting a brilliant blue light which is
surrounded by a halo of the fumes of boron fluoride.
_Sulphates_, _nitrates_ and _phosphates_ generally require the
application of more or less heat, when they too are rapidly and
energetically decomposed. Calcium phosphate is attacked in the cold
like lime, giving out a brilliant white light, and producing calcium
fluoride and gaseous oxyfluoride of phosphorus, POF_{3}. _Calcium
carbonate_ also becomes raised to brilliant incandescence when exposed
to fluorine gas, as does also normal _sodium carbonate_; but curiously
enough the bicarbonates of the alkalies do not react with fluorine
even at red heat. Perhaps this may be explained by the fact that
fluorine has no action at available temperatures upon carbon dioxide.