their respective fluorides. When fluorine is delivered into an aqueous
solution of hydriodic acid, each bubble as it enters produces a flash
of flame, and if the fluorine is being evolved fairly rapidly there is
a series of very violent detonations. A curious reaction also occurs
when fluorine is similarly passed into a 50 per cent. aqueous solution
of hydrofluoric acid itself, a flame being produced in the middle of
the liquid, accompanied by a series of detonations.

_Nitric acid_ vapor reacts with great violence with fluorine, a loud
explosion resulting. If fluorine is passed into the ordinary liquid
acid, each bubble as it enters produces a flame in the liquid.

_Ammonia gas_ is decomposed by fluorine with formation of a yellow
flame, forming hydrofluoric acid and liberating nitrogen. With a
solution of the gas in water, each bubble of fluorine produces an
explosion and flame, as in case of hydriodic acid.

_Phosphoric anhydride_, when heated to low redness, burns with a pale
flame in fluorine, forming a gaseous mixture of fluorides and
oxyfluoride of phosphorus. _Pentachloride and trichloride of
phosphorus_ both react most energetically with fluorine, instantly
producing a brilliant flame, and evolving a mixture of phosphorus
pentafluoride and free chlorine.

_Arsenious anhydride_ also affords a brilliant combustion, forming the
liquid trifluoride of arsenic, AsF_{3}. This liquid in turn appears to
react with more fluorine with considerable evolution of heat, probably
forming the pentafluoride, AsF_{5}. _Chloride of arsenic_, AsCl_{3},
is converted with considerable energy to the trifluoride, free
chlorine being liberated.