The Voice, a Waste Product. It is one of the most curious things in this body of ours that what we regard as its most wonderful power and gift, the voice, is, in one sense, a waste product. So ingenious is nature that she has actually made that marvelous musical instrument--the human voice--with its range, its flexibility, and its powers of expression, out of spent breath, or used-up air, which has done its work in the lungs and is being driven off to get rid of it. It is like using the waste from a kitchen sink to turn a mill. The organs that make the human voice were never built for that purpose in the first place. Unlike the eye and the ear, nature built no special organ for the voice alone, but simply utilized the windpipe and lung-bellows, the swallowing parts of the food passage (tongue, lips, and palate) and the nose, for that purpose, long after they had taken their own particular shapes for their own special ends. The important point about this is that a good voice requires not merely a large and well-developed "music box" in the windpipe, but good lungs, a well-shaped healthy throat, properly arched jaws,--which mean good, sound teeth,--clear and healthy nasal passages, and a flexible elastic tongue. Of course, the blood and the nerves supplying all these structures must be in good condition, as well. So practically, a good voice requires that the whole body should be healthy; and whatever we do to improve the condition of our nose, our teeth, our throat, our lungs, our digestion, and our circulation will help to improve the possibilities of our voice. There are, of course, many exceptions; but you will generally find that great singers have not only splendid lungs and large vocal cords, but good hearts, vigorous constitutions, and bodies above the average in both stature and strength. How the Voice is Produced. The chief parts of the breathing machine that nature has made over for talking purposes are the windpipe, or air tube, and the muscles in its walls. In the neck, about three inches above the collar bone, four or five of the rings of cartilage, or gristle,--which, you remember, give stiffening to the windpipe,--have grown together and enlarged to form a voice box, or _larynx_. [Illustration: THE VOCAL CORDS Looked at from above: position _A_, in quiet inspiration; _B_, in singing a low tone; _C_, in singing a high tone.] The upper edge of this voice box forms the projection in the front of the throat known by the rather absurd name of the "Adam's apple." This grows larger in proportion to the heaviness of the sounds to be made, and hence is larger in men than in women and boys. When the boy's voice box begins to grow to the man's in shape and size, his voice is likely to "break"; for it is changing from the high, clear boy's voice to the heavy, deep voice of the man.