There is no doubt that an indoor, sedentary life tends to high pressure far more than an active, outdoor one. This is partly due to the mental work and concentration that goes with it and partly to oxygen deficiency. The inhalation of oxygen lessens the viscosity of the blood and consequently the work of the heart and of the arterial muscles, while an excess of carbon-dioxide in the air increases the viscosity and the necessary heart force that must be expended. The amount of oxygen we inhale in the open is necessarily more than in confined buildings, and we all feel how difficult it is to drive our brains in a close, stuffy atmosphere. This points to the economic value of ventilation and space. Wise, moderate exercise also tends to lower pressure by promoting a general quickening of circulation throughout the whole body; the stagnant pools are flushed out and oxygenation becomes more perfect. Even severe exercise in health only raises pressure temporarily; the subsequent level in health is below the original. But where there is evidence of cardio and arterial disease, exercise must be taken wisely, moderately, and only slowly increased. This is done very effectually in some health resorts, where the patient is trained to mount gradually increasing slopes. The same effect is reached by graduated exercises. In all these methods pulse rate and arterial pressure are tested and serve as guides to further advance. Certain Bath treatments, such as Nauheim and its English adaptations, help materially to lower pressure and to hasten a sluggish blood flow. These act chiefly by dilating the blood-vessels at the surface of the whole body and thus relieving internal congestions and increasing oxygen exchange. The nature of our games and exercise in sclerosis needs careful thought. Golf, for instance, is very good if taken quietly, but some courses are so hilly that there is a good deal of strain put on the heart. If one is compelled to play on such a course, one must take it slowly, and not allow the spirit of the game to run away with one. Quiet sculling is one of the best exercises, for it works all the muscles of the body slowly and symmetrically, and the strain on heart and lungs is entirely under one’s own control. Swimming, again, is a most healthy exercise, if taken quietly and not in very cold water. I know of nothing that improves one’s wind so quickly. But all these exercises must be taken under advice and never pushed to the point of real fatigue or exhaustion.