True words, then, are not sounds separate from the spirit; they are the incarnated soul. I would never teach voice, I would never teach oratory, if words were not, in their true nature, Divine things, if they were not forms of the spirit and of the soul! =_ORGANS THAT PRODUCE, REINFORCE, AND GIVE RESONANT FORMS TO THE VOICE._= VOICE DEFINED. The human voice is that sound, caused by the vibration of the vocal cords in the larynx and reinforced by the resonant chambers, which reports the physical and mental states of man. CAUSE OF VOICE. Voice is caused by the contraction of the muscles of expiration, which brings sufficient pressure upon the lungs to drive the air from them out between the vocal cords, thus causing their edges to vibrate, thereby throwing the column of breath into such rapid vibration as to produce sound. ORGANS THAT PRODUCE VOICE. Larynx, (Including Vocal Cords), Lungs, Muscles of Respiration. _LARYNX._ The larynx is the principal organ of voice. It is situated in the front of the neck, and forms the prominence sometimes called “Adam’s apple”; it also forms a part of the anterior boundary of the pharynx. At the upper part it has the form of a triangular box, with one angle directly in front. It is composed of nine cartilages moved by muscles, and lined with mucous membrane. Six of its cartilages are in pairs; three are single. The three single cartilages are the thyroid, cricoid, and epiglottis; the three pairs are the arytenoid, cuneiform, and cornicula laryngis. The larynx is sometimes called a music-box; from it proceeds the sound called voice. [Illustration: =SIDE VIEW OF THE LARYNX AND TWO RINGS OF THE TRACHEA.=] VOCAL CORDS. Across the larynx are stretched the true vocal cords. [Illustration: =SHAPE OF THE GLOTTIS WHEN AT REST.=] [Illustration: =THE GLOTTIS DILATED.=] [Illustration: =GLOTTIS, CLOSED, AND MUSCLES CLOSING IT.=] Each cord consists of a band of yellow tissue, covered by mucous membrane. By means of the action of the muscles of the larynx that connect with the cartilages which enter into its structure, the vocal cords are so adjusted that when the muscles of expiration force the air, which is compressed in the lungs, out between these cords, their edges are set in vibration. This is the beginning of the sound which we call voice, but before it is heard in speech or song it is reinforced by the chambers of resonance.[1] ----- [1] For the function of the false, or superior vocal cords, see pp. 68-71, _Physical Culture_. PITCH.