=Constant Supply.=--Of so great importance is the matter of having a constant supply of unvitiated air that sanitariums for consumptives are now becoming common in which the principal feature is to have the patients enjoy a continuous out-door existence, day and night, being wrapped up and otherwise protected from cold and dampness. Consumptive symptoms often yield to this treatment.
=Individual Habit.=--Habit has much to do with our appreciation of pure air. If we recognize its value to health and to all the mental and physical activities, and insist upon a plentiful supply of pure oxygen, the habit soon becomes a second nature, and we instinctively feel uncomfortable upon entering an ill-ventilated room. In northern climates, economic considerations often interfere with the highest sanitary regulations. Householders, school boards, and church trustees frequently save fuel at the expense of health.
We may, however, by spending much time in poorly ventilated rooms, become so accustomed to the depressing influence of the impoverished atmosphere that we suffer a sort of semi-stupor without being conscious of the fact. How great a wrong is inflicted upon children in the school-room and in the crowded factory, by subjecting them, day after day, for months and years, to a vitiated atmosphere, laden with the poisonous exhalations from lungs and skin! Their growing bodies are stunted and their awakening intellects dulled, and the seeds of disease and weakness are implanted to develop into a harvest of wretchedness and misery in later life.
=Sea Air.=--When the breeze is off the ocean, the air is practically free from the exhalations of animals, the smoke and soot of chimneys, and the gases of sewers. The curative value of sea-air is well known. It comes richly laden with ozone, and its effect upon sojourners at the sea-side is very stimulating. Many persons are not strong enough to endure sea-bathing, yet gain much benefit from the sea-air.
=Mountain Air.=--The air of the mountains is pure. It is usually still, and seldom foggy. Being more rarefied than that of the low-lying valleys, it contains less oxygen in proportion to volume, but its lesser density gives to the oxygen greater activity.