Voice and speech.—Organ of voice; larynx, cavity of the larynx, glottis, vocal cords; the larynx at different ages and in different sexes.— Physiology of the larynx; mechanism of the voice; opinions as to the formation of the voice.—Galen, Fabricius Acquapendente, Dodart, Ferrein, Biot, Muller, Savart, Masson, and Longet.—Theories founded on laryngoscopy observations.—Formation of sounds in whistling.— Voice; speaking voice, mechanism of articulate sounds, vowels, consonants, timbre of the vowels; the tongue as an organ of pronunciation. —Singing; chest voice, falsetto voice, mixed voice; different theories on the formation of the falsetto: Muller, M. Segond, M. Longet, M. Fournie, M. Bataille, M. Mandl.—Timbres of the voice: high pitch, grave pitch. —Compass of voices: bass, baritone, tenor, contralto, mezzo-soprano, soprano.—Ventriloquy.