could be realized, not an atom of fresh air would be admitted during the hours of sleep. So little is the necessity for good air understood, that we find au able writer on health sanctioning, if not advocating, sleeping with the mouth under the clothes. His argument is that birds sleep with their heads under their wings, and he might have added, many animals with their noses buried in their fur; forgetful, however, that the feathers (and hair) form a natural respirator to warm and equalize the temperature of the air that passes freely through. There is therefore no analogy in a process for warming a constant supply of perfectly fresh air, and one for breathing the same air over and over again, and charged ad nauseam with organic impurities. Miss Nightingale approaches the subject of night air from the side of reason, and common-sense, and experience. She says:
"Another extraordinary fallacy is the dread of night air. What air can we breathe at night but night air? The choice is between pure night air from without and foul night air from within. Most people prefer the latter. An unaccountable choice. What will they say if it is proved to be true that fully one-half of all the disease we suffer from is occasioned by people sleeping with their windows shut? An open window most nights in the year can never hurt any one. This is not to say that light is not necessary for recovery. In great cities, night air is often the purest and best air to be had in the twenty-four hours. I could better understand in towns shutting the windows during the day than during the night for the sake of the sick. The absence of smoke, the quiet, all tend to making night the best time for airing the patients. One of our highest medical authorities on consumption and climate has told me that the air in London is never so pure as after ten o'clock at night."
These are the words of sound sense and experience. We shall only have to add to them, by-and-by, that it is not necessary to encounter the oftentimes great risk of sudden changes in temperature during the night, if we arrange one principal source of admission day and night to the house, and warm the air admitted. We may further remark that if there be the least ground for shrinking from night air, it is because of the often sudden and unforeseen change in the temperature, the very point overlooked in moving from fireplace to window in modern drawing-rooms.
Latterly some attention has been directed to a plan for diffused ventilation, adopted by Mr. M. Tobin. This plan consists of a series of vertical pipes placed along the walls, delivering fresh air in an upward current. In a multitude of pipes there is safety—much more so than in a multitude of counselors on this subject. Commenting upon this plan of course many critics claim priority of invention, and superiority in their modes of application, and the interests of the public thus go to the wall without any result. It is a pity that it cannot be made intelligible that whoever first opened a window or a door, for the express purpose of admitting air, originated ventilation; and that whoever first made a deeper recess for the lowest sash-bar, so that when the
