Page:Guide to health.djvu/28

 We should all be as much against the breathing of impure air as we are against the drinking of dirty water and the eating of dirty food; but the air we breathe is, as a rule, far more impure than the water we drink or the food we eat. We are all worshippers of concrete objects; those things that can be seen and felt are regarded by us as of far greater importance than those which are invisible and intangible. Since air belongs to this latter class of objects, we fail to realise the evil wrought by the impure air that we breathe. We would think twice before eating the leavings of another man's food, or drinking out of a cup polluted by another man's lips. Even those who have not the least sense of shame or repugnance would never eat another man's vomit, or drink the water which has been spat out by him; even those who are dying of hunger and thirst would refuse to do it. But, alas, how few of us realise that the air we inhale is so often the impure and poisonous air which has been exhaled by others, and which is surely no less objectionable than a man's vomit! How strange that men should sit and sleep together for hours in closed rooms, and go on inhaling the deadly air exhaled by themselves and their companions! How fortunate for man that air should be so light and diffusive, and capable of penetrating the smallest holes! Even when the