Source : Webster's Revised Unabridged Dictionary (1913)

Impalpability \Im*pal`pa*bil"i*ty\, n. [Cf. F.
   impalpabilit['e].]
   The quality of being impalpable. --Jortin.

Source : WordNet®

impalpability
     n : the quality of being intangible [syn: {intangibility}, {intangibleness}]
         [ant: {tangibility}, {tangibility}]