dactylology

Fingerspelling is also known as a "hand alphabet" or "dactylology".

On Dactylology.

Fingerspelling (or dactylology) is the representation of the letters of a writing system, and sometimes numeral systems, using only the hands.

Baker also wrote for the Penny Cyclopædia various topographical articles, and those on the Instruction of the Blind, Dactylology, Deaf and Dumb, George Dalgamo, and the Abbé Sicard.

That's correct,' the fat lady smiled, and continued: 'Now, I had of course learned sign-language or dactylology - which in my mind I'd called dumbspeak - and I also knew that some deaf people could carry on perfectly normal conversations, which I termed 'deafspeak'.