The Collaborative International Dictionary of English v.0.48:

Volatileness \Vol"a*tile*ness\, Volatility \Vol`a*til"i*ty\, n.
   [Cf. F. volatilit['e].]
   Quality or state of being volatile; disposition to evaporate;
   changeableness; fickleness.
   [1913 Webster]

   Syn: See Levity.
        [1913 Webster]