The healthiness or unhealthiness of a house depends greatly upon its degree of cleanliness. Dirty houses are always more or less unwholesome. In country places care should be taken that no puddles of dirty water remain close to the house, as they not only render the air damp, but cause much dirt to be brought in on the feet. Slops of dirty water, tea-leaves, coffee-grounds, etc., should never be thrown out near the house, all decaying vegetable and animal matter being injurious. Cabbage leaves, potato and apple-parings, and other waste vegetable matters, should never be thrown into the dust-bin. It is far the safest plan to burn them, which can always be done if they are first dried by throwing them at the back of the fire or in the ash-pit.

The inside of a house becomes unclean not only from the dust carried in by the air and the dirt brought in by the feet, but from the odor given out by our skin and with the breath. This odor is absorbed by all porous substances, as the walls, floors, and ceilings, and gives rise to that close, unwholesome smell which is present in all unclean houses, especially such as are overcrowded. No house with such a smell can possibly be a healthy place to live in. This animal effluvium is taken up by some substances much more readily than others. Walls that are covered with paper smell much more offensively than those that are painted. And in rooms where one paper has been pasted over another the whole thickness of paper may absorb it. Painted or lime-washed walls are much to be preferred to paper walls for crowded dwellings and for sleeping-rooms.

Woolen garments, carpets, and curtains absorb such odors freely, and give them out for a long time. Rough wooden floors also take them up, and consequently require frequent washing. For this reason smoothed, waxed, or painted floors are preferable to rough wooden ones.

The wholesomeness of a dwelling is much increased by frequently whitewashing such parts of it as can be treated in this manner—the cellar, storeroom, etc. The dirt and old whitewash should be first washed away with a brush and abundance of clean water.