It is essential to perfect health that every avenue to the lungs should be kept open and free, and that the air cells should be kept clear, for if the walls of the cells thicken, oxygen cannot penetrate them. If these cells are not properly filled during respiration, the walls thicken, and substances collect in the cells. If any trouble occurs in the air cells, except for traumatic reasons, it will first be found in the apexes of the lungs. In the production of tone, whether on a low, high, or medium pitch, the vocal cords are drawn so closely together that the air cannot immediately escape from the lungs; therefore, unable to get out readily, it is pressed up into the apexes of the lungs by the expiratory muscles, filling the air cells to the utmost, thus keeping them clear and their walls thin and healthy. In correct singing or speaking, the apexes of the lungs are filled with air. Tubercule seeks devitalized tissue for its development. Therefore tuberculosis usually begins in the apexes of the lungs because they are not kept clear and healthy through proper respiration and vocal exercise. Voice was given to man to make him strong and expressive, to give him life and power. THE EFFECT OF THE VOICE UPON THE STOMACH. The stomach is the principal organ of digestion. Out of the nutriment taken into it all the tissues of the body are renewed. It lies under the diaphragm, and is held in place by the abdominal muscles. The stomach is moved during respiration, descending with every inspiration, and rising with every expiration. In addition to this exercise during the production of tone, the stomach is held firmly between the diaphragm and abdominal muscles. At the close of the tone the muscles which thus hold the stomach relax.