George Catlin spent years traveling among the North American native tribes. He painted their portraits and aspects of their cultures.
He set up a museum in the U. S., then toured Europe with his paintings (and Mahaska II). Then he toured the Amazon River, doing similar work with the native people there.
At some point he decided that he had observed something really important, so he wrote a book about it.
His observation was that native people had very low childhood and infant mortality rates. He attributed this to the tendency of most groups of them to strap infants on a board to sleep, and for their mothers to push their mouths shut. This habit he thought they carried with them throughout their adult lives.
His observation was that people of European ancestory had a tendency to breathe through their mouths, causing all kinds of health and cosmetic problems.
So shut your mouth when you breathe, or you could end up looking like this:
George Catlin’s books can be found here.
Shut Your Mouth and Save Your Life!