The intercostal muscles raise the ribs. The diaphragm is drawn down by contraction, thus adding to the enlargement of the chest by increasing its depth. The abdominal muscles relax and allow the stomach, liver, and other organs in the abdomen to move downward to make room for the depressed diaphragm. This causes a vacuum in the chest. The lungs expand to fill this vacuum and the air rushes in to fill the expanding lungs. EXPIRATION The intercostal, and a part of the abdominal, muscles depress the ribs and lessen the chest cavity anteriorly and laterally. The abdominal muscles compress the abdomen and force up the diaphragm which is now relaxed, thus lessening the depth of the thorax. This pressure forces the air from the lungs and prepares them for another inspiration. CORRECT METHOD That the lateral-abdominal--more accurately chest-abdominal--breathing is correct and natural for both male, and female, and that the shoulders should remain as fixed as were Demosthenes' under the points of the swords hung over them, is now so generally admitted as to need no argument here. If any one has still a doubt on the subject let him observe a sleeping infant. It affords a perfect example of lateral-abdominal breathing, and no one can have a suspicion of sex from any difference in this function. Among the lower animals sex shows no difference in breathing at any age. All the peculiarities of female breathing are the results of habits acquired in after life. Chest and shoulder heaving are vicious and evidence impeded breathing. The singer who, forgetting the lower thorax, breathes with the upper only is sure to fail. Therefore breathe from the _lower_ part of the trunk, using the whole muscular system cooerdinately--_from below_ upward. In other words breathe deeply, and _control deeply_, but with the whole body--from below, not with the upper chest only, or with lateral expansion only, or abdominal expansion only. Every teacher and pupil should remember that "singing and speaking require wind and muscle," hence the breathing power must be fully developed. Weak breathing and failure to properly focus the voice are the most frequent causes of singing off the key. They are much more common and mischievous than lack of "ear." Dr. May tested the breathing of 85 persons, most of them Indians, and found that 79 out of the 85 used abdominal breathing. The chest breathers were from classes "civilized" and more or less "cultured." Nature has provided that for quiet breathing when at rest the air shall pass through the nose. But when a person is taking active exercise, and consequently demands more air, he naturally and of necessity opens the mouth so as to breathe more fully. While speaking or singing the air is necessarily taken in through the mouth. BREATH CONTROL