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.

ACTION OF FLUORINE UPON A FEW ORGANIC COMPOUNDS.

Chloroform.—­When chloroform is saturated with fluorine, and subsequently boiled, carbon tetrafluoride, hydrofluoric acid and chlorine are evolved.  If a drop of chloroform is agitated in a glass tube with excess of fluorine, a violent explosion suddenly occurs, accompanied by a flash of flame, and the tube is shattered to pieces.  The reaction is very lively when fluorine is evolved in the midst of a quantity of chloroform, a persistent flame burns beneath the surface of the liquid, carbon is deposited, and fluorides of hydrogen and carbon are evolved together with chlorine.

Methyl chloride is decomposed by fluorine, even at -23 deg., with production of a yellow flame, deposition of carbon, and liberation of fluorides of hydrogen and carbon and free chlorine.  With the vapor of methyl chloride, as pointed out in the description of the electrolysis, violent explosions occur.

Ethyl alcohol vapor at once takes fire in fluorine gas, and the liquid is decomposed with explosive violence without deposition of carbon.  Aldehyde is formed to a considerable extent during the reaction.