The outlet of the basin is at the lowest point, and is preferably in the front portion of the bottom. The plug is a buoyant one, and automatically rises to uncover the outlet when the water in the basin reaches a certain height. The lower end of the plug is conical, and is ground to closely fit the opening without binding. The plug, after rising by its buoyancy, to pass off an excessive quantity of water, closes by its own weight as the water lowers in the basin. To empty the bowl for use, the plug is raised by hand, by grasping the knob. This plug is an automatic seal, preventing the admission of noxious gases into and through the basin, and an effective waste and automatic overflow device combined. It is little liable to get out of order, and can easily be kept clean. ,; This invention has been patented by Mr. James W. Reid, of Evansville, Ind.