that gas is taken up to some extent by what is actually hurtful to life. When this is the condition of the atmosphere outside the dwelling, it is necessarily much worse within it, for there the displacement of impure air by pure cannot take place so rapidly. The consequences are as already stated. Large parts of our town populations never have sufficient oxygen; their lives are feeble and full of suffering, and numbers die before their time. Such facts are painful to contemplate; but a knowledge of them puts the wise man on his guard, and he may do much for himself. In the choice of a house he will remember the advantage of a great air-space around it, and of plenty of space within it, so that bedrooms may not be overcrowded. Or, if a large house is beyond his means, he will take care that the rooms are not crowded with furniture, for every piece of furniture excludes an equal bulk of air. When he enters the house he will see that at all times as much fresh air from the outside is admitted, by means of open doors and windows, as can be allowed without inconvenience from cold; and as often as possible ho will have a blow through, to clear out all odd corners where foul air may linger. "Pure air and good food make pure blood, and only pure blood will give good health."
