It is not so much by day that people suffer from the effects of poor ventilating. For then most of us are compelled by the force of circumstances and the exigencies of our work to move about from one place to another, even if it is only from room to room. It is in the evenings, and winter evenings in particular, that the atmosphere of the dwelling-rooms becomes contaminated. The family sits by the fireside, with the windows and door closed, and they never notice how stuffy and close the room is becoming, until someone comes in from the outside air and beseeches them to open the window.

Yet they go on sitting in that poisoned air, and one or two of them become drowsy and sit half asleep, with the result that when bedtime comes they have to face a restless night. Others, perhaps, find their heads aching, and attribute it to the fact they are working too hard during the day.

But it is only when they go to bed in rooms with the windows closed that the chief harm comes. Considering what a large proportion of our lives we spend in our bedrooms, it is of vital importance that the air should be, if anything, purer than that of the rooms we live in by day. For at night we are not moving about, but lying still, and the air does not get a chance of renewing itself unless the ventilation is efficient. Many people complain that they can scarcely wake up in the mornings, they feel so heavy. Or that when they do rouse themselves they have a headache, which it takes hours to get rid of. All this might be avoided by the use of the open window.

The objection to it generally consists in the fact that it makes a draught. There is no necessity for this, however. There are some cranks who have much to account for in regard to this matter. They boast that they can sleep close to a window which is open top and bottom to its fullest extent, and are proud to say that they have waked up in the morning to find that the rain had been coming in and had soaked the bedclothes through and through.

There may be a few constitutions which can stand this, but they are certainly in a hopeless minority. The majority of people would find themselves in “Queer Street” if they attempted such folly, for folly it is without a doubt. In one case where a father adopted vigorous methods of this sort with his children it ended in one of them getting an inflammation of the ear, which resulted in incurable deafness.

There is reason in all things, ventilation included. And fresh air can be secured without any draught at all. A few inches top and bottom, or only at the top if the weather be very stormy, makes all the difference, either in a sitting-room or a bedroom. Better still is the plan of fixing a block of wood the width of the window frame below the lower sash. That leaves a space between the upper and lower sashes, which ensures a constant supply of fresh air. If this be adopted the atmosphere will always be pure and healthy, even if the window is never opened any farther.

It is vastly better to have this constant supply of pure air in small doses than to throw the window open wide after the atmosphere has become hot and unpleasant.

Sometimes, however, it happens that in spite of all our efforts we have to breathe air containing some deleterious matter, germs or dust or what ever else it may be. To meet this contingency, Nature has provided a filter of her own. It consists of a network inside the nostrils. That is why it is of such importance to breathe through the nose instead of the mouth. If all children were taught to do this there would be fewer colds and fevers. The nostrils would arrest the unwholesome particles before they had a chance of reaching the tonsils, which are such a suitable soil for their growth.

Needless to say, pure air is of greater value when it is inhaled as freely as possible. In order to bring this about, it is necessary to breathe deeply. There are not many people who get the best value out of their lungs. As a rule, respiration is much too light. In order to remedy this defect, breathing exercises are of great value. The way to carry them out is to stand with the hands on the hips and breathe slowly in and out, inwardly counting four each time in a deliberate manner, and expanding the chest to its fullest possible extent.

The mistake usually made is to lift the chest with each inspiration. This only raises it, it does not expand it. The proper way is to breathe from the abdomen and lower part of the chest wall. When this is done every part of the lung is filled with air, and this has the great advantage of preventing the air inside the lung spaces from stagnating in any one part, an occurrence which is always prone to lead to the onset of congestion or disease.