\Dac`tyl*ol"o*gy\, n. [Gr. da`ktylos finger +
-logy.]
The art of communicating ideas by certain movements and
positions of the fingers; -- a method of conversing practiced
by the deaf and dumb.
Note: There are two different manual alphabets, the one-hand
      alphabet (which was perfected by Abb['e] de l'Ep['e]e,
      who died in 1789), and the two-hand alphabet. The
      latter was probably based on the manual alphabet
      published by George Dalgarus of Aberdeen, in 1680. See
      Illustration in Appendix.