Shall the windows and doors where a child sleeps, be kept closed; or shall they be suffered to remain open a part or the whole of the night? This must be determined by circumstances. If there are no doors but such as communicate with apartments whose air is equally impure with that in which the child is, it is preferable to keep them closed. If the windows cannot be opened without exposing the child to a current of air, it is perhaps the less of two evils, not to open them. But we are not usually driven to such extremities. In some instances, windows are constructed--and all of them ought to be--so that they can be lowered from the top. When this is not the case, something can be placed before the window to break the current, so that it need not fall directly upon the child. Closing the blinds will partially effect this, where blinds exist. I have known many an individual who was in the habit of sleeping with his windows open during the whole year, and without any obvious evil consequences. Dr. Gregory was of this habit. But if adults--not trained to it--can acquire such a habit with impunity, with how much more safety could children be trained to it from the very first year. Macnish says, "there can be no doubt that a gentle current pervading our sleeping apartments, is in the highest degree ESSENTIAL TO HEALTH." This consideration--I mean the impurity of sleeping rooms, even after every precaution has been used to keep them ventilated--affords one of the strongest inducements to going abroad early in the morning (especially when there is no other room which either adults or children can occupy) while the nursery or chamber is aired and ventilated. The utility of _rising_ early, I hope no one can doubt; but some have doubts of the propriety of going abroad, till the dew has "passed away." Such should be reminded, by the foregoing train of remarks, that early walking may be a choice of evils; and that if it _is_ on the whole advantageous to adults, it cannot be less so to children. And as soon as the sun has chased away the vapors of the night, if the weather is tolerable, most children should be carried abroad. SEC. 4. _The Bed._ This should never be of feathers. There are many reasons for this prohibition, especially to the feeble. 1. They are too warm. Infants should by all means be kept warm enough, as I have all along insisted. But excess of heat excites or stimulates the skin, causing an unnatural degree of perspiration, and thus inducing weakness or debility. 2. When we first enter a room in which there is a feather bed which has been occupied during the night, we are struck with the offensive smell of the air. This is owing to a variety of causes; one of which probably is, that beds of this kind are better adapted to absorb and retain the effluvia of our bodies. But let the causes be what they may, the effects ought, if possible, to be avoided; for both experience and authority combine to pronounce them very injurious.