This is a very important matter in a country like the United States, where there is so much change of domicile, and that particularly in a city like New York on the first of May. Floors dirty enough to make housekeepers desperate when they think of the bare possibility of being able to clean them, are first scrubbed with sand, then rubbed with the aid of a stiff brush with a lye of caustic soda, and washed with hot water. Then, after the lapse of an hour or so, and before the floor is dry, it is moistened with very dilute hydrochloric acid, and then with a thin, uniform paste of bleaching powder that is, hypochlorite of lime. After having remained over night, it should be washed off in the morning. Housekeepers are then astonished at the beauty of the floor. When no grease spots are present, the application of the caustic soda may be omitted.