Air bathing, breathing, hot-air baths, ozone and oxygen therapy have all been used. Air bathing is most beneficial in that it tones up the muscles and develops efficient skin reaction. Breathing pure air by means of rhythmic diaphragmatic breathing should form part of every health program. The ozone and oxygen treatments and hot-air baths have little value and act mainly as symptomatic treatments. Tobacco smoking could also be mentioned under the heading of Air. Inhalation of these poisonous gases pollutes the bloodstream and not only causes respiratory diseases, but aggravates many conditions in other parts of the body.