Air, air, the precious boon of heaven, which all may have, will bless you with its invigorating influence, if you will not refuse it entrance. Welcome it, cultivate a love for it, and it will prove a precious soother of the nerves. Air must be in constant circulation to be kept pure. The influence of pure, fresh air is to cause the blood to circulate healthfully through the system. It refreshes the body and tends to render it strong and healthy, while at the same time its influence is decidedly felt upon the mind, imparting a degree of composure and serenity. It excites the appetite, and renders the digestion of food more perfect, and induces sound and sweet sleep.—Testimonies for the Church 1:702 (1870). CH 60.1