But in order to get plenty of air it is not indispensable to go to forests or mountains or to the seaside; we can also get it at home, although not with the same amount of oxygen. To absorb much air we must breathe deeply and keep in the inspired air, and endeavor to get it into all parts of the lungs. In ordinary life we forget this and we get just as much air into us with our superficial breathing as is necessary to keep us alive and to feel no harm from our want of air. Most people breathe only superficially, and only inspire deeper when mounting the staircase, unless, indeed, they adopt the less healthy habit of reaching the first floor by the elevator. But as it is of apparent benefit to us to get as much air into our lungs as possible, we improve this state of affairs by breathing exercises. The great importance of these breathing exercises for the prolongation of human life has been especially insisted on by Sir Herman Weber.[252] But before him, Hamel and Harry Campbell[253] had already demonstrated the great therapeutic results of respiratory exercises. Sir Herman Weber recommends commencing with moderately deep inspirations and expirations, continued during from three to five minutes once or twice a day, and then gradually increasing to ten minutes or a quarter of an hour. The depth of each inspiration and expiration, and the duration of holding the breath, are to be increased only gradually. Sir Herman Weber advises inspiring in an erect position, with raised arms and closed mouth, bending the body forward during expiration so that the fingers touch the ground or the toes. Footnote 252: Loc. cit. Footnote 253: Dr. Harry Campbell on “Respiratory Exercise in the Treatment of Disease,” London, 1907. According to this authority, besides the influence on the circulation, the respiratory movements keep up the nutrition and efficiency of the lungs, and also maintain the elasticity of the chest walls, which are apt to become stiff in old age and thus interfere with the free action of the lungs and pleura. These respiratory exercises can also be performed in a sitting or horizontal position. According to Sir Lauder Brunton, the deep respiratory movements act as a kind of massage to the lungs, thoracic walls, pericardium, and heart. Sir Herman Weber mentions that he has seen persons who get out of breath, even after short walks and climbs, and who for this reason abstained from such, and consequently suffered in health and spirits, become, by means of these movements, active walkers and climbers, gaining improvement in every function of the body, and outliving by many years their brothers and sisters who had not practiced them. He also specially recommends these breathing exercises to literary workers, statesmen, professional men, and others who get no time to take the usual methods of exercise. In certain heart troubles—for example, dilatation of the heart—these movements are contraindicated.