"Many persons during sleep breathe through open mouth, a practice which, in miasmatic regions, is held to render them much more liable to miasmatic poisoning than if they breathed entirely through the nose, the hairs on the inside of the nostrils acting in some measure as a filter to prevent the entrance of miasmatic exhalations. To prevent sleeping with the mouth open, M. F. Pinckard, of New Orleans, Louisiana, patented, through the Scientific American Patent Agency, the "Sanitary B race i". Its operation is sufficiently plain without further description, and it effectually prevents the dropping of the jaw and the opening of the mouth during sleep." Scientific American, January 14, 1871.