When one inhales, the lungs seem to grow. As the cells are filled with air, the chest proportionately enlarges. At the same time, the ribs and the diaphragm assume a new position. The result is that the chest, the between-rib muscles, and the diaphragm are all very strenuously exercised. By proper breathing, the various muscles involved are constantly trained; they are developed and made elastic to such an extent that the lungs are not required to stand alone in their resistance against adverse conditions, both without and within. * * * * * The lungs expand during inhalation; they contract during exhalation. A full breath dilates the lungs to their maximum capacity; they relax to the minimum size when the breath is completely expelled. By practice one can readily learn to influence the various movements, and gradually to control them. The practice of the first exercises in the series given includes sudden exhalation, slow exhalation, and rhythmic exhalation. These tend to reduce the quantity of air that is left in the lungs when the breath is expelled. Such residual air is poisonous, and an excess of it, due to improper breathing, is very injurious. Its retention in the lung cells not only lessens the space available to be filled with fresh air, but it also acts as a direct agent for ill in the bodily processes. How Consciously Controlled Breathing Makes You Resist Disease It should be added, and with emphasis, that _the habit of deep breathing makes one immune to the germs of various diseases_. The practice of breath-control gives a toughened fiber to the whole breathing apparatus. This and the constant purifying of the blood develop the body’s vital forces to the highest degree possible, against which disease is rendered powerless. Thus one may enter into possession of the health and strength that are his by right; and thus, and thus only, shall he know the joy of life. Here is an illustration of what may be done by serious and persistent attention to breathing. It must be understood, however, that I by no means advise others to follow my example, although I believe it quite possible for anybody--man, woman, boy or girl--by constant practice, to develop the same perfect resistance that I myself have.