The nostrils are the proper channels for the breath of life. The mouth is designed for other important purposes; and when it is not opened for some good purpose, it were better that it remain closed. Some fifteen or twenty years ago I read an article on this subject, and since then have been trying to reduce to practice the advice to keep the mouth shut, with some progress, I think, and certainly with some benefit. Many a cold, sore throat, toothache, etc., can be prevented by keeping the mouth closed, when going out in cold weather. I have held evening meetings in stormy, winter weather, where the good people were afraid to have the house properly ventilated, and as the result, the close of the meeting would find me in perspiration. When obliged to go out, I would keep my mouth so strictly closed till I reached my quarters that I feared I should give the impression that I was unsociable; and in this way, I would escape colds almost entirely while almost all others would be very much afflicted with them. But this is not the sole cause of the difference; something must be credited to my different manner of living in other respects. Hygienic living in general is the best preventive of this difficulty, as well as of others.
Think of the cases of those of your acquaintance who, attending singing school, have ruined their voices, contracting a bronchial affection for life. After singing two hours in a heated and unventilated house, they would get into sleighs and go singing on their way home. The throat, irritated and inflamed, suddenly exposed to the frosty air of a northern winter! It was a wonder that any could live through such an ordeal. Think of it, friends. When going out, especially after having been using your voice, keep your mouth shut. On going to bed, shut your mouth carefully, and thus go to sleep, being covered well and not fearing to have your room well ventilated.
The Health Reformer, February 1876.