The philosophy of the human voice: Embracing its physiological history; together with a system of principles by which criticism in the art of elocution may be rendered intelligible, and instruction, definite and comprehensive. To which is added a brief analysis of song and recitative.

“With over 30 diagrams and charts, including myriad musical notations to show the pitch and duration of syllables, the text offers a systematic notation for the description of speech sounds, followed by a detailed treatise on elocution, used for generations to teach oratory, articulation, and speech therapy" (ANB). Digital facsimile from Google Books at this link.