Dac′tyl‐ol″o‐gy (?), n. [Gr. δάκτυλοσ 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.
☞ There are two different manual alphabets, the one-hand alphabet (which was perfected by Abbé de l'Epée, 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.